Йодид калия как пишется

Clinical data
Trade names	iOSAT, SSKI, ThyroSafe, ThyroShield, others
AHFS/Drugs.com	Monograph
ATC code	R05CA02 (WHO) S01XA04 (WHO), V03AB21 (WHO)
Legal status
Legal status	US: OTC
Identifiers
IUPAC name Potassium iodide
CAS Number	7681-11-0
PubChem CID	4875
DrugBank	DB06715
ChemSpider	4709
UNII	1C4QK22F9J
KEGG	D01016
ChEBI	CHEBI:8346
ChEMBL	ChEMBL1141
CompTox Dashboard (EPA)	DTXSID7034836
ECHA InfoCard	100.028.782
Chemical and physical data
Formula	KI
3D model (JSmol)	Interactive image
Density	3.13[1] g/cm3
Melting point	681 °C (1,258 °F)
Boiling point	1,330 °C (2,430 °F)
Solubility in water	1280 mg/mL (0 °C (32 °F)) 1400 mg/mL (20 °C (68 °F)) 1760 mg/mL (60 °C (140 °F)) 2060 mg/mL (100 °C (212 °F)) [2] 2 0 0
SMILES [K+].[I-]
InChI InChI=1S/HI.K/h1H;/q;+1/p-1  Key:NLKNQRATVPKPDG-UHFFFAOYSA-M

Potassium iodide is a chemical compound, medication, and dietary supplement.^[3][4] It is a medication used for treating hyperthyroidism, in radiation emergencies, and for protecting the thyroid gland when certain types of radiopharmaceuticals are used.^[5] In the third world it is also used for treating skin sporotrichosis and phycomycosis.^[5][6] It is a supplement used by people with low dietary intake of iodine.^[4] It is administered orally.^[5]

Common side effects include vomiting, diarrhea, abdominal pain, rash, and swelling of the salivary glands.^[5] Other side effects include allergic reactions, headache, goitre, and depression.^[6] While use during pregnancy may harm the baby, its use is still recommended in radiation emergencies.^[5] Potassium iodide has the chemical formula KI.^[7] Commercially it is made by mixing potassium hydroxide with iodine.^[8][9]

Potassium iodide has been used medically since at least 1820.^[10] It is on the World Health Organization’s List of Essential Medicines.^[11] Potassium iodide is available as a generic medication and over the counter.^[12] Potassium iodide is also used for the iodization of salt.^[4]

Medical uses[edit]

Dietary supplement[edit]

Potassium-iodide is a nutritional-supplement in animal feeds and also in the human diet. In humans it is the most common additive used for «iodizing» table salt (a public health measure to prevent iodine deficiency in populations that get little seafood). The oxidation of iodide causes slow loss of iodine content from iodised salts that are exposed to excess air. The alkali metal iodide salt, over time and exposure to excess oxygen and carbon dioxide, slowly oxidizes to metal carbonate and elemental iodine, which then evaporates.^[13] Potassium iodate (KIO₃) is used to iodize some salts so that the iodine is not lost by oxidation. Dextrose or sodium thiosulfate are often added to iodized table salt to stabilize potassium iodide thus reducing loss of the volatile chemical.^[14]

Thyroid protection[edit]

Thyroid iodine uptake blockade with potassium iodide is used in nuclear medicine scintigraphy and therapy with some radioiodinated compounds that are not targeted to the thyroid, such as iobenguane (MIBG), which is used to image or treat neural tissue tumors, or iodinated fibrinogen, which is used in fibrinogen scans to investigate clotting. These compounds contain iodine, but not in the iodide form. However, since they may be ultimately metabolized or break down to radioactive iodide, it is common to administer non-radioactive potassium iodide to ensure that iodide from these radiopharmaceuticals is not sequestered by the normal affinity of the thyroid for iodide.

U.S. Food and Drug Administration-approved dosing of potassium iodide for this purpose with iobenguane, is as follows (per 24 hours): infants less than 1 month old, 16 mg; children 1 month to 3 years, 32 mg; children 3 years to 18 years, 65 mg; adults 130 mg.^[15] However, some sources recommend alternative dosing regimens.^[16]

Not all sources are in agreement on the necessary duration of thyroid blockade, although agreement appears to have been reached about the necessity of blockade for both scintigraphic and therapeutic applications of iobenguane. Commercially available iobenguane is labeled with iodine-123, and product labeling recommends administration of potassium iodide 1 hour prior to administration of the radiopharmaceutical for all age groups,^[17] while the European Association of Nuclear Medicine recommends (for iobenguane labeled with either isotope), that potassium iodide administration begin one day prior to radiopharmaceutical administration, and continue until the day following the injection, with the exception of new-borns, who do not require potassium iodide doses following radiopharmaceutical injection.^[16][18]

Product labeling for diagnostic iodine-131 iobenguane recommends potassium iodide administration one day before injection and continuing 5 to 7 days following administration, in keeping with the much longer half-life of this isotope and its greater danger to the thyroid.^[19] Iodine-131 iobenguane used for therapeutic purposes requires a different pre-medication duration, beginning 24–48 hours prior to iobenguane injection and continuing 10–15 days following injection.^[20]

Nuclear accidents[edit]

In 1982, the U.S. Food and Drug Administration approved potassium iodide to protect thyroid glands from radioactive iodine involving accidents or fission emergencies.^{[citation needed]} In an accidental event or attack on a nuclear power plant, or in nuclear bomb fallout, volatile fission product radionuclides may be released. Of these products, ¹³¹
I
(Iodine-131) is one of the most common and is particularly dangerous to the thyroid gland because it may lead to thyroid cancer.^{[citation needed]} By saturating the body with a source of stable iodide prior to exposure, inhaled or ingested ¹³¹
I
tends to be excreted, which prevents radioiodine uptake by the thyroid. According to one 2000 study «KI administered up to 48 h before ¹³¹
I
exposure can almost completely block thyroid uptake and therefore greatly reduce the thyroid absorbed dose. However, KI administration 96 h or more before ¹³¹
I
exposure has no significant protective effect. In contrast, KI administration after exposure to radioiodine induces a smaller and rapidly decreasing blockade effect.»^[22] For optimal prevention, KI must be dosed daily until a risk of significant exposure to radioiodine by either inhalation or ingestion no longer exists.^{[citation needed]}

Emergency 130 milligrams potassium iodide doses provide 100 mg iodide (the other 30 mg is the potassium in the compound), which is roughly 700 times larger than the normal nutritional need (see recommended dietary allowance) for iodine, which is 150 micrograms (0.15 mg) of iodine (as iodide) per day for an adult. A typical tablet weighs 160 mg, with 130 mg of potassium iodide and 30 mg of excipients, such as binding agents.

Potassium iodide cannot protect against any other mechanisms of radiation poisoning, nor can it provide any degree of protection against dirty bombs that produce radionuclides other than those of iodine.

The potassium iodide in iodized salt is insufficient for this use.^[23] A likely lethal dose of salt (more than a kilogram^[24]) would be needed to equal the potassium iodide in one tablet.^[25]

The World Health Organization does not recommend KI prophylaxis for adults over 40 years, unless the radiation dose from inhaled radioiodine is expected to threaten thyroid function, because the KI side effects increase with age and may exceed the KI protective effects; «…unless doses to the thyroid from inhalation rise to levels threatening thyroid function, that is of the order of about 5 Gy. Such radiation doses will not occur far away from an accident site.»^[21]

The U.S. Department of Health and Human Services restated these two years later as «The downward KI (potassium iodide) dose adjustment by age group, based on body size considerations, adheres to the principle of minimum effective dose. The recommended standard (daily) dose of KI for all school-age children is the same (65 mg). However, adolescents approaching adult size (i.e., >70 kg [154 lbs]) should receive the full adult dose (130 mg) for maximal block of thyroid radioiodine uptake. Neonates ideally should receive the lowest dose (16 mg) of KI.»^[26]

SSKI (i.e., the «saturated solution of KI» rather than tablets) may be used in radioiodine-contamination emergencies (i.e., nuclear accidents) to «block» the thyroid’s uptake of radioiodine, at a dose of two drops of SSKI per day for an adult. This is not the same as blocking the thyroid’s release of thyroid hormone, for which the adult dose is different (and is actually higher by a factor of 7 or 8^{[citation needed]}), and for which KI anti-radiation pills (not a common medical treatment form of KI) are not usually available in pharmacies, or normally used in hospitals, or by physicians.^{[citation needed]} Although the two forms of potassium iodide are completely interchangeable, normally in practice the SSKI solution, which is the historical medical form of high dose iodine, is generally used for all medical purposes save for radioiodine prophylaxis. For protection of the thyroid against radioiodine (iodine-131) contamination, the convenient standard 130 mg KI pill is used, if available.^{[citation needed]} As noted, the equivalent two drops of SSKI (equaling the dose of one KI pill) may be used for this purpose, if the pills are not available.^{[citation needed]}

Side effects[edit]

There is reason for caution with prescribing the ingestion of high doses of potassium iodide and iodate, because their unnecessary use can cause conditions such as the Jod-Basedow phenomena, trigger and/or worsen hyperthyroidism and hypothyroidism, and then cause temporary or even permanent thyroid conditions. It can also cause sialadenitis (an inflammation of the salivary gland), gastrointestinal disturbances, and rashes. Potassium iodide is also not recommended for people with dermatitis herpetiformis and hypocomplementemic vasculitis – conditions that are linked to a risk of iodine sensitivity.^[27]

There have been some reports of potassium iodide treatment causing swelling of the parotid gland (one of the three glands that secrete saliva), due to its stimulatory effects on saliva production.^[28]

A saturated solution of KI (SSKI) is typically given orally in adult doses several times a day (5 drops of SSKI assumed to be 1⁄3 mL) for thyroid blockade (to prevent the thyroid from excreting thyroid hormone) and occasionally this dose is also used, when iodide is used as an expectorant (the total dose is about one gram KI per day for an adult). The anti-radioiodine doses used for ¹³¹
I
uptake blockade are lower, and range downward from 100  mg a day for an adult, to less than this for children (see table). All of these doses should be compared with the far lower dose of iodine needed in normal nutrition, which is only 150 μg per day (150 micrograms, not milligrams).

At maximal doses, and sometimes at much lower doses, side effects of iodide used for medical reasons, in doses of 1000 times the normal nutritional need, may include: acne, loss of appetite, or upset stomach (especially during the first several days, as the body adjusts to the medication). More severe side effects that require notification of a physician are: fever, weakness, unusual tiredness, swelling in the neck or throat, mouth sores, skin rash, nausea, vomiting, stomach pains, irregular heartbeat, numbness or tingling of the hands or feet, or a metallic taste in the mouth.^[29]

In the event of a radioiodine release the ingestion of prophylaxis potassium iodide, if available, or even iodate, would rightly take precedence over perchlorate administration, and would be the first line of defence in protecting the population from a radioiodine release. However, in the event of a radioiodine release too massive and widespread to be controlled by the limited stock of iodide and iodate prophylaxis drugs, then the addition of perchlorate ions to the water supply, or distribution of perchlorate tablets would serve as a cheap, efficacious, second line of defense against carcinogenic radioiodine bioaccumulation.

The ingestion of goitrogen drugs is, much like potassium iodide also not without its dangers, such as hypothyroidism. In all these cases however, despite the risks, the prophylaxis benefits of intervention with iodide, iodate or perchlorate outweigh the serious cancer risk from radioiodine bioaccumulation in regions where radioiodine has sufficiently contaminated the environment.

Potassium iodide in its raw form is a mild irritant and should be handled with gloves. Chronic overexposure can have adverse effects on the thyroid. Potassium iodide is a possible teratogen.^{[citation needed]}

Industrial uses[edit]

KI is used with silver nitrate to make silver iodide (AgI), an important chemical in film photography. KI is a component in some disinfectants and hair treatment chemicals. KI is also used as a fluorescence quenching agent in biomedical research, an application that takes advantage of collisional quenching of fluorescent substances by the iodide ion. However, for several fluorophores addition of KI in μM-mM concentrations results in increase of fluorescence intensity, and iodide acts as fluorescence enhancer.^[30]

Potassium iodide is a component in the electrolyte of dye sensitised solar cells (DSSC) along with iodine.

Potassium iodide finds its most important applications in organic synthesis mainly in the preparation of aryl iodides in the Sandmeyer reaction, starting from aryl amines. Aryl iodides are in turn used to attach aryl groups to other organics by nucleophilic substitution, with iodide ion as the leaving group.

Chemistry[edit]

Potassium iodide is an ionic compound which is made of the following ions: K⁺I⁻. It crystallises in the sodium chloride structure. It is produced industrially by treating KOH with iodine.^[31]

It is a white salt, which is the most commercially significant iodide compound, with approximately 37,000 tons produced in 1985. It absorbs water less readily than sodium iodide, making it easier to work with.

Aged and impure samples are yellow because of the slow oxidation of the salt to potassium carbonate and elemental iodine.^[31]

Inorganic chemistry[edit]

Since the iodide ion is a mild reducing agent, I⁻ is easily oxidised to iodine (I₂) by powerful oxidising agents such as chlorine:

This reaction is employed in the isolation of iodine from natural sources. Air will oxidize iodide, as evidenced by the observation of a purple extract when aged samples of KI are rinsed with dichloromethane. As formed under acidic conditions, hydriodic acid (HI) is a stronger reducing agent.^[32][33][34]

Like other iodide salts, KI forms triiodide (I−3) when combined with elemental iodine.

Unlike I₂, I−3 salts can be highly water-soluble. Through this reaction, iodine is used in redox titrations. Aqueous KI₃, «Lugol’s solution», is used as a disinfectant and as an etchant for gold surfaces.

Potassium iodide and silver nitrate are used to make silver(I) iodide, which is used for high speed photographic film and for cloud seeding:

Organic chemistry[edit]

KI serves as a source of iodide in organic synthesis. A useful application is in the preparation of aryl iodides from arenediazonium salts.^[35][36]

KI, acting as a source of iodide, may also act as a nucleophilic catalyst for the alkylation of alkyl chlorides, bromides, or mesylates.

History[edit]

Potassium iodide has been used medically since at least 1820.^[10] Some of the earliest uses included cures for syphilis,^[10] lead and mercury poisoning.

Chernobyl[edit]

Potassium iodide’s (KI) value as a radiation protective (thyroid blocking) agent was demonstrated following the Chernobyl nuclear reactor disaster in April, 1986. A saturated solution of potassium iodide (SSKI) was administered to 10.5 million children and 7 million adults in Poland^[26][37] as a preventative measure against accumulation of radioactive ¹³¹
I
in the thyroid gland.

Reports differ concerning whether people in the areas immediately surrounding Chernobyl itself were given the supplement.^[38][18] However the US Nuclear Regulatory Commission (NRC) reported, «thousands of measurements of I-131 (radioactive iodine) activity…suggest that the observed levels were lower than would have been expected had this prophylactic measure not been taken. The use of KI…was credited with permissible iodine content in 97% of the evacuees tested.»^[18]

With the passage of time, people living in irradiated areas where KI was not available have developed thyroid cancer at epidemic levels, which is why the US Food and Drug Administration (FDA) reported «The data clearly demonstrate the risks of thyroid radiation… KI can be used [to] provide safe and effective protection against thyroid cancer caused by irradiation.»^[39]

Chernobyl also demonstrated that the need to protect the thyroid from radiation was greater than expected. Within ten years of the accident, it became clear that thyroid damage caused by released radioactive iodine was virtually the only adverse health effect that could be measured. As reported by the NRC, studies after the accident showed that «As of 1996, except for thyroid cancer, there has been no confirmed increase in the rates of other cancers, including leukemia, among the… public, that have been attributed to releases from the accident.»^[40]

But equally important to the question of KI is the fact that radioactivity releases are not «local» events. Researchers at the World Health Organization accurately located and counted the residents with cancer from Chernobyl and were startled to find that «the increase in incidence [of thyroid cancer] has been documented up to 500 km from the accident site… significant doses from radioactive iodine can occur hundreds of kilometers from the site, beyond emergency planning zones.»^[21] Consequently, far more people than anticipated were affected by the radiation, which caused the United Nations to report in 2002 that «The number of people with thyroid cancer… has exceeded expectations. Over 11,000 cases have already been reported.»^[41]

Nagasaki[edit]

These findings were consistent with studies of the effects of previous radioactivity releases. In 1945, millions of Japanese were exposed to radiation from nuclear weapons, and the effects can still be measured. Today, nearly half (44.8%) the survivors of Nagasaki studied have identifiable thyroid disease, with an editorial in The Journal of the American Medical Association reporting «it is remarkable that a biological effect from a single brief environmental exposure nearly 60 years in the past is still present and can be detected.»^[42]

Nuclear weapons testing[edit]

The development of thyroid cancer among residents in the North Pacific from radioactive fallout following the United States’ nuclear weapons testing in the 1950s (on islands nearly 200 miles downwind of the tests) were instrumental in the 1978 decision by the FDA to issue a request for the availability of KI for thyroid protection in the event of a release from a commercial nuclear power plant or weapons-related nuclear incident. Noting that KI’s effectiveness was «virtually complete» and finding that iodine in the form of KI was substantially superior to other forms including iodate (KIO₃) in terms of safety, effectiveness, lack of side effects, and speed of onset, the FDA invited manufacturers to submit applications to produce and market KI.^[43]

Fukushima[edit]

It was reported on March 16, 2011, that potassium iodide tablets were given preventively to U.S. Naval air crew members flying within 70 nautical miles of the Fukushima Daiichi Nuclear Power Plant damaged in the earthquake (8.9/9.0 magnitude) and ensuing tsunami on March 11, 2011. The measures were seen as precautions, and the Pentagon said no U.S. forces have shown signs of radiation poisoning. By March 20, the US Navy instructed personnel coming within 100 miles of the reactor to take the pills.^[44]

The Netherlands[edit]

In the Netherlands, the central storage of iodine-pills is located in Zoetermeer, near The Hague. In 2017, the Dutch government distributed pills to hundreds of thousands of residents who lived within a certain distance of nuclear power plants and met some other criteria.^[45][46]

Belgium[edit]

By 2020, potassium iodide tablets are made available free of charge for all residents in all pharmacies throughout the country.^[47]

Formulations[edit]

Three companies (Anbex, Inc., Fleming Co, and Recipharm of Sweden) have met the strict FDA requirements for manufacturing and testing of KI, and they offer products (IOSAT, ThyroShield, and ThyroSafe,^[48] respectively) which are available for purchase. In 2012, Fleming Co. sold all its product rights and manufacturing facility to other companies and no longer exists. ThyroShield is currently not in production. The Swedish manufacturing facility for Thyrosafe, a half-strength potassium iodide tablet for thyroid protection from radiation, was mentioned on the secret US 2008 Critical Foreign Dependencies Initiative leaked by Wikileaks in 2010.^[49]

Tablets of potassium iodide are supplied for emergency purposes related to blockade of radioiodine uptake, a common form of radiation poisoning due to environmental contamination by the short-lived fission product ¹³¹
I
.^[50] Potassium iodide may also be administered pharmaceutically for thyroid storm.

For reasons noted above, therapeutic drops of SSKI, or 130 mg tablets of KI as used for nuclear fission accidents, are not used as nutritional supplements, since an SSKI drop or nuclear-emergency tablet provides 300 to 700 times more iodine than the daily adult nutritional requirement. Dedicated nutritional iodide tablets containing 0.15 mg (150 micrograms (μg)) of iodide, from KI or from various other sources (such as kelp extract) are marketed as supplements, but they are not to be confused with the much higher pharmaceutical dose preparations.

Potassium iodide can be conveniently prepared in a saturated solution, abbreviated SSKI. This method of delivering potassium iodide doesn’t require a method to weigh out the potassium iodide, thus allowing it to be used in an emergency situation. KI crystals are simply added to water until no more KI will dissolve and instead sits at the bottom of the container. With pure water, the concentration of KI in the solution depends only on the temperature. Potassium iodide is highly soluble in water thus SSKI is a concentrated source of KI. At 20 degrees Celsius the solubility of KI is 140-148 grams per 100 grams of water.^[51] Because the volumes of KI and water are approximately additive, the resulting SSKI solution will contain about 1.00 gram (1000 mg) KI per milliliter (mL) of solution. This is 100% weight/volume (note units of mass concentration) of KI (one gram KI per mL solution), which is possible because SSKI is significantly more dense than pure water—about 1.67 g/mL.^[52] Because KI is about 76.4% iodide by weight, SSKI contains about 764 mg iodide per mL. This concentration of iodide allows the calculation of the iodide dose per drop, if one knows the number of drops per milliliter. For SSKI, a solution more viscous than water, there are assumed to be 15 drops per mL; the iodide dose is therefore approximately 51 mg per drop. It is conventionally rounded to 50 mg per drop.

The term SSKI is also used, especially by pharmacists, to refer to a U.S.P. pre-prepared solution formula, made by adding KI to water to prepare a solution containing 1000 mg KI per mL solution (100% wt/volume KI solution), to closely approximate the concentration of SSKI made by saturation. This is essentially interchangeable with SSKI made by saturation, and also contains about 50 mg iodide per drop.

• Saturated solutions of potassium iodide can be an emergency treatment for hyperthyroidism (so-called thyroid storm), as high amounts of iodide temporarily suppress secretion of thyroxine from the thyroid gland.^[53] The dose typically begins with a loading dose, then 1⁄3 mL SSKI (5 drops or 250 mg iodine as iodide), three times per day.
• Iodide solutions made from a few drops of SSKI added to drinks have also been used as expectorants to increase the water content of respiratory secretions and encourage effective coughing.^[54]
• SSKI has been proposed as a topical treatment for sporotrichosis, but no trials have been conducted to determine the efficacy or side effects of such treatment.^[55]
• Potassium iodide has been used for symptomatic treatment of erythema nodosum patients for persistent lesions whose cause remains unknown. It has been used in cases of erythema nodosum associated with Crohn’s disease.^[56]
• Due to its high potassium content, SSKI is extremely bitter, and if possible it is administered in a sugar cube or small ball of bread. It may also be mixed into much larger volumes of juices.
• Neither SSKI or KI tablets form nutritional supplements, since the nutritional requirement for iodine is only 150 micrograms (0.15 mg) of iodide per day. Thus, a drop of SSKI provides 50/0.15 = 333 times the daily iodine requirement, and a standard KI tablet provides twice this much.

See also[edit]

• Elephant toothpaste

References[edit]

External links[edit]

• «Potassium iodide». Drug Information Portal. U.S. National Library of Medicine.
• World Health Organization’s guidelines for iodine prophylaxis following a nuclear accident

Clinical data
Trade names	iOSAT, SSKI, ThyroSafe, ThyroShield, others
AHFS/Drugs.com	Monograph
ATC code	R05CA02 (WHO) S01XA04 (WHO), V03AB21 (WHO)
Legal status
Legal status	US: OTC
Identifiers
IUPAC name Potassium iodide
CAS Number	7681-11-0
PubChem CID	4875
DrugBank	DB06715
ChemSpider	4709
UNII	1C4QK22F9J
KEGG	D01016
ChEBI	CHEBI:8346
ChEMBL	ChEMBL1141
CompTox Dashboard (EPA)	DTXSID7034836
ECHA InfoCard	100.028.782
Chemical and physical data
Formula	KI
3D model (JSmol)	Interactive image
Density	3.13[1] g/cm3
Melting point	681 °C (1,258 °F)
Boiling point	1,330 °C (2,430 °F)
Solubility in water	1280 mg/mL (0 °C (32 °F)) 1400 mg/mL (20 °C (68 °F)) 1760 mg/mL (60 °C (140 °F)) 2060 mg/mL (100 °C (212 °F)) [2] 2 0 0
SMILES [K+].[I-]
InChI InChI=1S/HI.K/h1H;/q;+1/p-1  Key:NLKNQRATVPKPDG-UHFFFAOYSA-M

Potassium iodide is a chemical compound, medication, and dietary supplement.^[3][4] It is a medication used for treating hyperthyroidism, in radiation emergencies, and for protecting the thyroid gland when certain types of radiopharmaceuticals are used.^[5] In the third world it is also used for treating skin sporotrichosis and phycomycosis.^[5][6] It is a supplement used by people with low dietary intake of iodine.^[4] It is administered orally.^[5]

Common side effects include vomiting, diarrhea, abdominal pain, rash, and swelling of the salivary glands.^[5] Other side effects include allergic reactions, headache, goitre, and depression.^[6] While use during pregnancy may harm the baby, its use is still recommended in radiation emergencies.^[5] Potassium iodide has the chemical formula KI.^[7] Commercially it is made by mixing potassium hydroxide with iodine.^[8][9]

Potassium iodide has been used medically since at least 1820.^[10] It is on the World Health Organization’s List of Essential Medicines.^[11] Potassium iodide is available as a generic medication and over the counter.^[12] Potassium iodide is also used for the iodization of salt.^[4]

Medical uses[edit]

Dietary supplement[edit]

Potassium-iodide is a nutritional-supplement in animal feeds and also in the human diet. In humans it is the most common additive used for «iodizing» table salt (a public health measure to prevent iodine deficiency in populations that get little seafood). The oxidation of iodide causes slow loss of iodine content from iodised salts that are exposed to excess air. The alkali metal iodide salt, over time and exposure to excess oxygen and carbon dioxide, slowly oxidizes to metal carbonate and elemental iodine, which then evaporates.^[13] Potassium iodate (KIO₃) is used to iodize some salts so that the iodine is not lost by oxidation. Dextrose or sodium thiosulfate are often added to iodized table salt to stabilize potassium iodide thus reducing loss of the volatile chemical.^[14]

Thyroid protection[edit]

Thyroid iodine uptake blockade with potassium iodide is used in nuclear medicine scintigraphy and therapy with some radioiodinated compounds that are not targeted to the thyroid, such as iobenguane (MIBG), which is used to image or treat neural tissue tumors, or iodinated fibrinogen, which is used in fibrinogen scans to investigate clotting. These compounds contain iodine, but not in the iodide form. However, since they may be ultimately metabolized or break down to radioactive iodide, it is common to administer non-radioactive potassium iodide to ensure that iodide from these radiopharmaceuticals is not sequestered by the normal affinity of the thyroid for iodide.

U.S. Food and Drug Administration-approved dosing of potassium iodide for this purpose with iobenguane, is as follows (per 24 hours): infants less than 1 month old, 16 mg; children 1 month to 3 years, 32 mg; children 3 years to 18 years, 65 mg; adults 130 mg.^[15] However, some sources recommend alternative dosing regimens.^[16]

Not all sources are in agreement on the necessary duration of thyroid blockade, although agreement appears to have been reached about the necessity of blockade for both scintigraphic and therapeutic applications of iobenguane. Commercially available iobenguane is labeled with iodine-123, and product labeling recommends administration of potassium iodide 1 hour prior to administration of the radiopharmaceutical for all age groups,^[17] while the European Association of Nuclear Medicine recommends (for iobenguane labeled with either isotope), that potassium iodide administration begin one day prior to radiopharmaceutical administration, and continue until the day following the injection, with the exception of new-borns, who do not require potassium iodide doses following radiopharmaceutical injection.^[16][18]

Product labeling for diagnostic iodine-131 iobenguane recommends potassium iodide administration one day before injection and continuing 5 to 7 days following administration, in keeping with the much longer half-life of this isotope and its greater danger to the thyroid.^[19] Iodine-131 iobenguane used for therapeutic purposes requires a different pre-medication duration, beginning 24–48 hours prior to iobenguane injection and continuing 10–15 days following injection.^[20]

Nuclear accidents[edit]

In 1982, the U.S. Food and Drug Administration approved potassium iodide to protect thyroid glands from radioactive iodine involving accidents or fission emergencies.^{[citation needed]} In an accidental event or attack on a nuclear power plant, or in nuclear bomb fallout, volatile fission product radionuclides may be released. Of these products, ¹³¹
I
(Iodine-131) is one of the most common and is particularly dangerous to the thyroid gland because it may lead to thyroid cancer.^{[citation needed]} By saturating the body with a source of stable iodide prior to exposure, inhaled or ingested ¹³¹
I
tends to be excreted, which prevents radioiodine uptake by the thyroid. According to one 2000 study «KI administered up to 48 h before ¹³¹
I
exposure can almost completely block thyroid uptake and therefore greatly reduce the thyroid absorbed dose. However, KI administration 96 h or more before ¹³¹
I
exposure has no significant protective effect. In contrast, KI administration after exposure to radioiodine induces a smaller and rapidly decreasing blockade effect.»^[22] For optimal prevention, KI must be dosed daily until a risk of significant exposure to radioiodine by either inhalation or ingestion no longer exists.^{[citation needed]}

Emergency 130 milligrams potassium iodide doses provide 100 mg iodide (the other 30 mg is the potassium in the compound), which is roughly 700 times larger than the normal nutritional need (see recommended dietary allowance) for iodine, which is 150 micrograms (0.15 mg) of iodine (as iodide) per day for an adult. A typical tablet weighs 160 mg, with 130 mg of potassium iodide and 30 mg of excipients, such as binding agents.

Potassium iodide cannot protect against any other mechanisms of radiation poisoning, nor can it provide any degree of protection against dirty bombs that produce radionuclides other than those of iodine.

The potassium iodide in iodized salt is insufficient for this use.^[23] A likely lethal dose of salt (more than a kilogram^[24]) would be needed to equal the potassium iodide in one tablet.^[25]

The World Health Organization does not recommend KI prophylaxis for adults over 40 years, unless the radiation dose from inhaled radioiodine is expected to threaten thyroid function, because the KI side effects increase with age and may exceed the KI protective effects; «…unless doses to the thyroid from inhalation rise to levels threatening thyroid function, that is of the order of about 5 Gy. Such radiation doses will not occur far away from an accident site.»^[21]

The U.S. Department of Health and Human Services restated these two years later as «The downward KI (potassium iodide) dose adjustment by age group, based on body size considerations, adheres to the principle of minimum effective dose. The recommended standard (daily) dose of KI for all school-age children is the same (65 mg). However, adolescents approaching adult size (i.e., >70 kg [154 lbs]) should receive the full adult dose (130 mg) for maximal block of thyroid radioiodine uptake. Neonates ideally should receive the lowest dose (16 mg) of KI.»^[26]

SSKI (i.e., the «saturated solution of KI» rather than tablets) may be used in radioiodine-contamination emergencies (i.e., nuclear accidents) to «block» the thyroid’s uptake of radioiodine, at a dose of two drops of SSKI per day for an adult. This is not the same as blocking the thyroid’s release of thyroid hormone, for which the adult dose is different (and is actually higher by a factor of 7 or 8^{[citation needed]}), and for which KI anti-radiation pills (not a common medical treatment form of KI) are not usually available in pharmacies, or normally used in hospitals, or by physicians.^{[citation needed]} Although the two forms of potassium iodide are completely interchangeable, normally in practice the SSKI solution, which is the historical medical form of high dose iodine, is generally used for all medical purposes save for radioiodine prophylaxis. For protection of the thyroid against radioiodine (iodine-131) contamination, the convenient standard 130 mg KI pill is used, if available.^{[citation needed]} As noted, the equivalent two drops of SSKI (equaling the dose of one KI pill) may be used for this purpose, if the pills are not available.^{[citation needed]}

Side effects[edit]

There is reason for caution with prescribing the ingestion of high doses of potassium iodide and iodate, because their unnecessary use can cause conditions such as the Jod-Basedow phenomena, trigger and/or worsen hyperthyroidism and hypothyroidism, and then cause temporary or even permanent thyroid conditions. It can also cause sialadenitis (an inflammation of the salivary gland), gastrointestinal disturbances, and rashes. Potassium iodide is also not recommended for people with dermatitis herpetiformis and hypocomplementemic vasculitis – conditions that are linked to a risk of iodine sensitivity.^[27]

There have been some reports of potassium iodide treatment causing swelling of the parotid gland (one of the three glands that secrete saliva), due to its stimulatory effects on saliva production.^[28]

A saturated solution of KI (SSKI) is typically given orally in adult doses several times a day (5 drops of SSKI assumed to be 1⁄3 mL) for thyroid blockade (to prevent the thyroid from excreting thyroid hormone) and occasionally this dose is also used, when iodide is used as an expectorant (the total dose is about one gram KI per day for an adult). The anti-radioiodine doses used for ¹³¹
I
uptake blockade are lower, and range downward from 100  mg a day for an adult, to less than this for children (see table). All of these doses should be compared with the far lower dose of iodine needed in normal nutrition, which is only 150 μg per day (150 micrograms, not milligrams).

At maximal doses, and sometimes at much lower doses, side effects of iodide used for medical reasons, in doses of 1000 times the normal nutritional need, may include: acne, loss of appetite, or upset stomach (especially during the first several days, as the body adjusts to the medication). More severe side effects that require notification of a physician are: fever, weakness, unusual tiredness, swelling in the neck or throat, mouth sores, skin rash, nausea, vomiting, stomach pains, irregular heartbeat, numbness or tingling of the hands or feet, or a metallic taste in the mouth.^[29]

In the event of a radioiodine release the ingestion of prophylaxis potassium iodide, if available, or even iodate, would rightly take precedence over perchlorate administration, and would be the first line of defence in protecting the population from a radioiodine release. However, in the event of a radioiodine release too massive and widespread to be controlled by the limited stock of iodide and iodate prophylaxis drugs, then the addition of perchlorate ions to the water supply, or distribution of perchlorate tablets would serve as a cheap, efficacious, second line of defense against carcinogenic radioiodine bioaccumulation.

The ingestion of goitrogen drugs is, much like potassium iodide also not without its dangers, such as hypothyroidism. In all these cases however, despite the risks, the prophylaxis benefits of intervention with iodide, iodate or perchlorate outweigh the serious cancer risk from radioiodine bioaccumulation in regions where radioiodine has sufficiently contaminated the environment.

Potassium iodide in its raw form is a mild irritant and should be handled with gloves. Chronic overexposure can have adverse effects on the thyroid. Potassium iodide is a possible teratogen.^{[citation needed]}

Industrial uses[edit]

KI is used with silver nitrate to make silver iodide (AgI), an important chemical in film photography. KI is a component in some disinfectants and hair treatment chemicals. KI is also used as a fluorescence quenching agent in biomedical research, an application that takes advantage of collisional quenching of fluorescent substances by the iodide ion. However, for several fluorophores addition of KI in μM-mM concentrations results in increase of fluorescence intensity, and iodide acts as fluorescence enhancer.^[30]

Potassium iodide is a component in the electrolyte of dye sensitised solar cells (DSSC) along with iodine.

Potassium iodide finds its most important applications in organic synthesis mainly in the preparation of aryl iodides in the Sandmeyer reaction, starting from aryl amines. Aryl iodides are in turn used to attach aryl groups to other organics by nucleophilic substitution, with iodide ion as the leaving group.

Chemistry[edit]

Potassium iodide is an ionic compound which is made of the following ions: K⁺I⁻. It crystallises in the sodium chloride structure. It is produced industrially by treating KOH with iodine.^[31]

It is a white salt, which is the most commercially significant iodide compound, with approximately 37,000 tons produced in 1985. It absorbs water less readily than sodium iodide, making it easier to work with.

Aged and impure samples are yellow because of the slow oxidation of the salt to potassium carbonate and elemental iodine.^[31]

Inorganic chemistry[edit]

Since the iodide ion is a mild reducing agent, I⁻ is easily oxidised to iodine (I₂) by powerful oxidising agents such as chlorine:

This reaction is employed in the isolation of iodine from natural sources. Air will oxidize iodide, as evidenced by the observation of a purple extract when aged samples of KI are rinsed with dichloromethane. As formed under acidic conditions, hydriodic acid (HI) is a stronger reducing agent.^[32][33][34]

Like other iodide salts, KI forms triiodide (I−3) when combined with elemental iodine.

Unlike I₂, I−3 salts can be highly water-soluble. Through this reaction, iodine is used in redox titrations. Aqueous KI₃, «Lugol’s solution», is used as a disinfectant and as an etchant for gold surfaces.

Potassium iodide and silver nitrate are used to make silver(I) iodide, which is used for high speed photographic film and for cloud seeding:

Organic chemistry[edit]

KI serves as a source of iodide in organic synthesis. A useful application is in the preparation of aryl iodides from arenediazonium salts.^[35][36]

KI, acting as a source of iodide, may also act as a nucleophilic catalyst for the alkylation of alkyl chlorides, bromides, or mesylates.

History[edit]

Potassium iodide has been used medically since at least 1820.^[10] Some of the earliest uses included cures for syphilis,^[10] lead and mercury poisoning.

Chernobyl[edit]

Potassium iodide’s (KI) value as a radiation protective (thyroid blocking) agent was demonstrated following the Chernobyl nuclear reactor disaster in April, 1986. A saturated solution of potassium iodide (SSKI) was administered to 10.5 million children and 7 million adults in Poland^[26][37] as a preventative measure against accumulation of radioactive ¹³¹
I
in the thyroid gland.

Reports differ concerning whether people in the areas immediately surrounding Chernobyl itself were given the supplement.^[38][18] However the US Nuclear Regulatory Commission (NRC) reported, «thousands of measurements of I-131 (radioactive iodine) activity…suggest that the observed levels were lower than would have been expected had this prophylactic measure not been taken. The use of KI…was credited with permissible iodine content in 97% of the evacuees tested.»^[18]

With the passage of time, people living in irradiated areas where KI was not available have developed thyroid cancer at epidemic levels, which is why the US Food and Drug Administration (FDA) reported «The data clearly demonstrate the risks of thyroid radiation… KI can be used [to] provide safe and effective protection against thyroid cancer caused by irradiation.»^[39]

Chernobyl also demonstrated that the need to protect the thyroid from radiation was greater than expected. Within ten years of the accident, it became clear that thyroid damage caused by released radioactive iodine was virtually the only adverse health effect that could be measured. As reported by the NRC, studies after the accident showed that «As of 1996, except for thyroid cancer, there has been no confirmed increase in the rates of other cancers, including leukemia, among the… public, that have been attributed to releases from the accident.»^[40]

But equally important to the question of KI is the fact that radioactivity releases are not «local» events. Researchers at the World Health Organization accurately located and counted the residents with cancer from Chernobyl and were startled to find that «the increase in incidence [of thyroid cancer] has been documented up to 500 km from the accident site… significant doses from radioactive iodine can occur hundreds of kilometers from the site, beyond emergency planning zones.»^[21] Consequently, far more people than anticipated were affected by the radiation, which caused the United Nations to report in 2002 that «The number of people with thyroid cancer… has exceeded expectations. Over 11,000 cases have already been reported.»^[41]

Nagasaki[edit]

These findings were consistent with studies of the effects of previous radioactivity releases. In 1945, millions of Japanese were exposed to radiation from nuclear weapons, and the effects can still be measured. Today, nearly half (44.8%) the survivors of Nagasaki studied have identifiable thyroid disease, with an editorial in The Journal of the American Medical Association reporting «it is remarkable that a biological effect from a single brief environmental exposure nearly 60 years in the past is still present and can be detected.»^[42]

Nuclear weapons testing[edit]

The development of thyroid cancer among residents in the North Pacific from radioactive fallout following the United States’ nuclear weapons testing in the 1950s (on islands nearly 200 miles downwind of the tests) were instrumental in the 1978 decision by the FDA to issue a request for the availability of KI for thyroid protection in the event of a release from a commercial nuclear power plant or weapons-related nuclear incident. Noting that KI’s effectiveness was «virtually complete» and finding that iodine in the form of KI was substantially superior to other forms including iodate (KIO₃) in terms of safety, effectiveness, lack of side effects, and speed of onset, the FDA invited manufacturers to submit applications to produce and market KI.^[43]

Fukushima[edit]

It was reported on March 16, 2011, that potassium iodide tablets were given preventively to U.S. Naval air crew members flying within 70 nautical miles of the Fukushima Daiichi Nuclear Power Plant damaged in the earthquake (8.9/9.0 magnitude) and ensuing tsunami on March 11, 2011. The measures were seen as precautions, and the Pentagon said no U.S. forces have shown signs of radiation poisoning. By March 20, the US Navy instructed personnel coming within 100 miles of the reactor to take the pills.^[44]

The Netherlands[edit]

In the Netherlands, the central storage of iodine-pills is located in Zoetermeer, near The Hague. In 2017, the Dutch government distributed pills to hundreds of thousands of residents who lived within a certain distance of nuclear power plants and met some other criteria.^[45][46]

Belgium[edit]

By 2020, potassium iodide tablets are made available free of charge for all residents in all pharmacies throughout the country.^[47]

Formulations[edit]

Three companies (Anbex, Inc., Fleming Co, and Recipharm of Sweden) have met the strict FDA requirements for manufacturing and testing of KI, and they offer products (IOSAT, ThyroShield, and ThyroSafe,^[48] respectively) which are available for purchase. In 2012, Fleming Co. sold all its product rights and manufacturing facility to other companies and no longer exists. ThyroShield is currently not in production. The Swedish manufacturing facility for Thyrosafe, a half-strength potassium iodide tablet for thyroid protection from radiation, was mentioned on the secret US 2008 Critical Foreign Dependencies Initiative leaked by Wikileaks in 2010.^[49]

Tablets of potassium iodide are supplied for emergency purposes related to blockade of radioiodine uptake, a common form of radiation poisoning due to environmental contamination by the short-lived fission product ¹³¹
I
.^[50] Potassium iodide may also be administered pharmaceutically for thyroid storm.

For reasons noted above, therapeutic drops of SSKI, or 130 mg tablets of KI as used for nuclear fission accidents, are not used as nutritional supplements, since an SSKI drop or nuclear-emergency tablet provides 300 to 700 times more iodine than the daily adult nutritional requirement. Dedicated nutritional iodide tablets containing 0.15 mg (150 micrograms (μg)) of iodide, from KI or from various other sources (such as kelp extract) are marketed as supplements, but they are not to be confused with the much higher pharmaceutical dose preparations.

Potassium iodide can be conveniently prepared in a saturated solution, abbreviated SSKI. This method of delivering potassium iodide doesn’t require a method to weigh out the potassium iodide, thus allowing it to be used in an emergency situation. KI crystals are simply added to water until no more KI will dissolve and instead sits at the bottom of the container. With pure water, the concentration of KI in the solution depends only on the temperature. Potassium iodide is highly soluble in water thus SSKI is a concentrated source of KI. At 20 degrees Celsius the solubility of KI is 140-148 grams per 100 grams of water.^[51] Because the volumes of KI and water are approximately additive, the resulting SSKI solution will contain about 1.00 gram (1000 mg) KI per milliliter (mL) of solution. This is 100% weight/volume (note units of mass concentration) of KI (one gram KI per mL solution), which is possible because SSKI is significantly more dense than pure water—about 1.67 g/mL.^[52] Because KI is about 76.4% iodide by weight, SSKI contains about 764 mg iodide per mL. This concentration of iodide allows the calculation of the iodide dose per drop, if one knows the number of drops per milliliter. For SSKI, a solution more viscous than water, there are assumed to be 15 drops per mL; the iodide dose is therefore approximately 51 mg per drop. It is conventionally rounded to 50 mg per drop.

The term SSKI is also used, especially by pharmacists, to refer to a U.S.P. pre-prepared solution formula, made by adding KI to water to prepare a solution containing 1000 mg KI per mL solution (100% wt/volume KI solution), to closely approximate the concentration of SSKI made by saturation. This is essentially interchangeable with SSKI made by saturation, and also contains about 50 mg iodide per drop.

• Saturated solutions of potassium iodide can be an emergency treatment for hyperthyroidism (so-called thyroid storm), as high amounts of iodide temporarily suppress secretion of thyroxine from the thyroid gland.^[53] The dose typically begins with a loading dose, then 1⁄3 mL SSKI (5 drops or 250 mg iodine as iodide), three times per day.
• Iodide solutions made from a few drops of SSKI added to drinks have also been used as expectorants to increase the water content of respiratory secretions and encourage effective coughing.^[54]
• SSKI has been proposed as a topical treatment for sporotrichosis, but no trials have been conducted to determine the efficacy or side effects of such treatment.^[55]
• Potassium iodide has been used for symptomatic treatment of erythema nodosum patients for persistent lesions whose cause remains unknown. It has been used in cases of erythema nodosum associated with Crohn’s disease.^[56]
• Due to its high potassium content, SSKI is extremely bitter, and if possible it is administered in a sugar cube or small ball of bread. It may also be mixed into much larger volumes of juices.
• Neither SSKI or KI tablets form nutritional supplements, since the nutritional requirement for iodine is only 150 micrograms (0.15 mg) of iodide per day. Thus, a drop of SSKI provides 50/0.15 = 333 times the daily iodine requirement, and a standard KI tablet provides twice this much.

See also[edit]

• Elephant toothpaste

References[edit]

External links[edit]

• «Potassium iodide». Drug Information Portal. U.S. National Library of Medicine.
• World Health Organization’s guidelines for iodine prophylaxis following a nuclear accident

Йодид калия

Полезное

Содержание

Фармакологическая группа вещества Калия йодид

Фармакологическое действие

Характеристика

Фармакология

Применение вещества Калия йодид

Противопоказания

Гиперчувствительность к йоду, выраженная и скрытая (для доз, превышающих 150 мкг/сут) гиперфункция щитовидной железы, токсическая аденома щитовидной железы, узловой зоб и другие доброкачественные опухоли щитовидной железы (для доз, превышающих 300 мкг/сут, за исключением предоперационной йодотерапии), герпетиформный дерматит Дюринга, туберкулез легких, нефрит, геморрагический диатез, нефроз, фурункулез, угревая сыпь, пиодермия.

Ограничения к применению

Беременность, кормление грудью.

Применение при беременности и кормлении грудью

Во время беременности и кормления грудью возможно применение только в физиологических (профилактических) дозах. Применение во время беременности может привести к угнетению функции щитовидной железы (гипотиреозу) и увеличению ее размеров у плода, а в период кормления грудью — к появлению сыпи и понижению функции щитовидной железы у новорожденного (при дозах свыше 300 мкг йода в день грудное вскармливание следует прекратить).

Побочные действия вещества Калия йодид

Взаимодействие

Антитиреоидный эффект усиливают (взаимно) антитиреоидные препараты. Тиреотропный гормон активирует аккумуляцию йода щитовидной железой, перхлорат и тиоцианат калия — тормозят. Прием высоких доз йодида одновременно с калийсберегающими диуретиками повышает риск развития гиперкалиемии и аритмии. При одновременном приеме с ингибиторами АПФ также повышается риск развития гиперкалиемии, с препаратами лития — риск развития гипотиреоза и возникновения зоба.

Передозировка

Способ применения и дозы

Меры предосторожности

До начала лечения необходимо исключить злокачественное поражение щитовидной железы. С осторожностью применяют у пациентов с нарушением функции почек (необходим периодический контроль уровня калия в крови).

Торговые названия с действующим веществом Калия йодид

Физические свойства

Йодид калия KI — соль щелочного металла калия и йодоводородной кислоты. Белый, при хранении на свету желтеет из-за окисления. Хорошо растворяется в воде (гидролиза нет).

Относительная молекулярная масса M_r = 166; относительная плотность для тв. и ж. состояния d = 3,115; t_пл = 681º C

Способ получения 

1. При температуре 150–200º C, в результате взаимодействия калия и йода, образуется йодид калия:

2K + I₂ = 2KI

2. Разбавленный раствор гидроксида калия реагирует с йодидом железа в атмосфере азота. При этом образуются йодид калия и осадок гидроксид железа:

2KOH + FeI₂ = 2KI + Fe(OH)₂↓

Качественная реакция

Качественная реакция на йодид калия — взаимодействие его с нитратом серебра, в результате реакции происходит образование осадка желтого цвета:

При взаимодействии с нитратом серебра, йодид калия образует нитрат калия и осадок йодид серебра:

KI + AgNO₃ = KNO₃ + AgI↓

Химические свойства

1. Йодид калия вступает в реакцию с простыми веществами:

1.1. Холодный йодид калия взаимодействует с хлором. В результате реакции происходит образование хлорида калия и осадка йода:

2KI + Cl₂ = 2KCl + I_2↓

1.2. Холодный йодид калия взаимодействует с бромом. В результате реакции происходит образование бромида калия и осадка йода:

2KI + Br₂ = 2KBr + I_2↓

2. Йодид калия способен вступать в реакцию со сложными веществами:

2.1. Йодид калия реагирует с кислотами:

2.1.1. Твердый йодид калия реагирует с концентрированной серной кислотой при 30 — 50º С. Взаимодействие данных веществ приводит к образованию осадка йода, газа сероводорода, воды и гидросульфата калия:

8KI + 9H₂SO₄ = 4I₂↓ + H₂S↑ + 4H₂O + 8KHSO₄

2.2. Йодид калия вступает в реакцию с солями:

2.2.1. Йодид калия реагирует с разбавленной серной кислотой и перманганатом калия. В результате данной реакции образуется осадок йод, сульфат марганца, вода и сульфат калия:

10KI + 8H₂SO₄ + 2KMnO₄ = 5I₂↓ + 2MnSO₄ + 8H₂O + 6K₂SO₄

3.2.2. В результате взаимодействия йодида калия с разбавленной серной кислотой и дихроматом калия происходит образование сульфата хрома, осадка йода, воды и сульфата калия:

6KI + 7H₂SO₄ + K₂Cr₂O₇ = Cr₂(SO₄)₃ + 3I₂↓ + 7H₂O + 4K₂SO₄

2.2.3. Йодид калия в разбавленной серной кислоте взаимодействует с сульфатом железа(III), образуя осадок йод, сульфат железа (II) и сульфат калия:

2KI + Fe₂(SO₄)₃ = I₂↓ +2FeSO₄ + K₂SO₄ 

Йо́дистый ка́лий (иодистый калий) или иоди́д ка́лия (йоди́д ка́лия) — неорганическое соединение, калиевая соль йодоводородной кислоты с химической формулой KI. Йодид калия представляет собой бесцветную кристаллическую соль, постепенно желтеющую (разлагающуюся) на свету.

Йодистый калий широко используется в качестве источника иодид-ионов. Применяется в медицине и ветеринарии как лекарственное средство, в сельском хозяйстве как удобрение, а также в фотографии и аналитической химии. В малых количествах наряду с иодатом калия добавляется в поваренную соль (для получения так называемой йодированной соли).

Йодистый калий в определениях и коротких высказываниях[править]

Йодистый калий в научной и научно-популярной литературе[править]

Йодистый калий в публицистике и мемуарах[править]

Йодистый калий в художественной литературе[править]

Йодистый калий в поэзии[править]

Источники[править]

См. также[править]

• Щелочные металлы
• Калий
• Йод
• Едкое кали
• Бертолетова соль
• Цианистый калий
• Хлористый калий
• Бромистый калий
• Поташ
• Калийная селитра
• Сода

Состав

Формула йодида калия — KI. В состав одной таблетки Калия йодида может входить 100 или 200 мкг активного вещества. Капли для глаз – это раствор, в котором содержится 3% активного вещества. В раствор Калия йодида может входить разное количество действующего вещества — 0,25%, 10–20%.

Форма выпуска

Производители выпускают таблетки, капли, а также раствор Калия йодида. Таблетки вмещаются в банки из оранжевого стекла. Раствор Калия йодида 3% расфасован во флаконах по 200 мл. Капли для глаз реализуются во флаконах по 10 мл.

Фармакологическое действие

Фармакопея свидетельствует, что препарат оказывает воздействие на функции щитовидной железы, влияя, в частности, на процесс образования гормонов. Он приостанавливает продукцию тиреотропного гормона, который вырабатывается в передней доли гипофиза, увеличивает активность секреции бронхиальных желез, способствуя отделению мокроты. Также Калия йодид обладает протеолитическими свойствами, то есть способствует расщеплению белков.

Если средство применяется местно, оно оказывает антисептическую активность, обеззараживая обработанные поверхности. Еще оно важное свойство этого лекарства – предупреждение процесса накопления в щитовидной железе радиоактивного йода. Препарат эффективно защищает щитовидную железу от влияния радиации.

Фармакокинетика и фармакодинамика

Если в окружающей среде содержится нормальное количество йода, то под воздействием избыточного количества йодидов приостанавливается процесс биосинтеза тиреоидных гормонов, уменьшается уровень чувствительности щитовидки к тиреотропному гормону гипофиза, а также блокируется продукция тиреотропного гормона гипофизом.

После того, как Калия йодид попадает внутрь, он полностью и быстро всасывается в тонком кишечнике. На протяжении двух часов он распределяется внутри клеток организма. Накопление происходит в большей степени в щитовидной железе, также йодид накапливается в молочных, слюнных железах, в слизистой желудка. Вещество проникает сквозь плаценту.

Из организма выводится через почки, причем, около 80 % дозы препарата выводится на протяжении 48 часов, а оставшаяся часть из организма выводится от 10 до 20 дней. Также частичное выведение происходит с секретами, выделяемыми слюнными, бронхиальными, потовыми и другими железами.

Показания к применению

Средство применяется в качестве препарата йода для лечения больных гипертиреозом (болезнь щитовидной железы), при развитии эндемического зоба (болезнь щитовидной железы, которая развивается в связи со сниженным содержанием в воде йода). Также его назначают в процессе подготовки к оперативным вмешательствам у людей с выраженной формой тиреотоксикоза (болезнь, связанная с повышенной функцией щитовидной железы человека). Лекарство назначается для профилактики поражения радиацией щитовидной железы. Как вспомогательный препарат применяется при лечении сифилиса.

Калия йодид назначается также при следующих болезнях:

• воспалительные болезни дыхательных путей;
• бронхиальная астма.

Глазные капли Калия йодид назначаются при следующих состояниях:

• болезни глаз (помутнение роговицы, катаракта, кровоизлияния);
• грибковые болезни роговицы и конъюнктивы.

Противопоказания

Нельзя назначать данное ЛС при следующих заболеваниях и состояниях:

• туберкулез;
• нефрит, нефроз;
• фурункулез, угревая сыпь;
• гнойные воспалительные процессы на кожных покровах;
• крапивница, геморрагический диатез;
• высокая чувствительность к йоду;
• беременность.

Побочные действия

В процессе лечения Калия йодидом могут развиваться явления йодизма. Это воспаление слизистых оболочек неинфекционного характера, которое сопровождается насморком, крапивницей, отеками слизистой оболочки носа, другими аллергическими реакциями. При приеме внутрь может отмечаться неприятное чувство в подложечной области.

Кроме того, в качестве побочных реакций может проявляться тахикардия, проблемы со сном, диарея, усиленное потоотделение.

При лечении большими дозами средства может развиваться гипертиреоз. Чаще всего это происходит у пожилых людей, у которых диагностирован токсический зоб узлового или диффузного типа.

Йодид Калия, инструкция по применению (Способ и дозировка)

Калия йодид принимают внутрь в виде растворов и таблеток, в/в введение противопоказано. При приеме препарата рекомендовано запивать его сладким чаем, киселем или молоком, чтобы предотвратить раздражение ЖКТ.

Пациентам, которым назначается Йодид Калия, инструкция по применению предполагает прием определенных доз средства при конкретном заболевании.

Если назначаются глазные капли Калия йодид, инструкция предусматривает применение 3% раствора который нужно закапывать в конъюнктивальный мешок. Капать в каждый глаз следует по 2 капли, делая это 3-4 раза в день. Период лечения продолжается от 10 до 15 дней, в зависимости от заболевания.

Людям, болеющим эндемическим зобом, внутрь назначается по 0,04 г ЛС 1 раз в неделю. Если больной страдает диффузным зобом, изначально ему показан прием по 0,04 г препарата трижды в день, после чего дозировку следует изменить: по 0,125 г 1 или 2 раза в день. Период терапии продолжается 20 дней, далее следует десятидневный перерыв.

С целью разжижения мокроты используется 1-3% раствор. Его нужно принимать по 2-3 ст. л. 3-4 раза ежедневно.

Как вспомогательное средство назначается при сифилисе, в основном, такое лечение целесообразно в третичном периоде. Под воздействием препарата уменьшаются боли, более интенсивно рассасываются инфильтраты. Для лечения сифилиса по 1 ст. л. 3-4% раствора нужно принимать трижды в день после употребления пищи.

Для лечения актиномикоза легких назначаются большие дозы средства — 1 ст. ложка 10-20% раствора четырежды в день.

С целью защиты от воздействия радиоактивного йода взрослые и дети после двухлетнего возраста должны получать по 0,125 г средства 1 раз в день. Детям до двух лет показан прием по 0,04 г в день. Принимать таблетки нужно каждый день, до того времени, пока не исчезнет угроза попадания в организм радиоактивного йода.

Чтобы обеспечить защиту щитовидной железы от влияния радофармацевтических препаратов, следует принимать по 0,125 г один раз в день в течение 5-10 дней.

Передозировка

При передозировке любым из препаратов Калия йодид может отмечаться окрашивание слизистых в коричневый оттенок. Также у пациента происходит рвота, его беспокоит боль в животе, приступы диареи. В тяжелых случаях может произойти дегидратация, развивается шоковое состояние.

При передозировке необходимо сразу промыть желудок и ввести пациенту Натрия тиосульфат. Также практикуется симптоматическое лечение, при необходимости проводится терапия, направленная на преодоление шокового состояния, на восстановление водно-электролитного баланса.

При хронической передозировке развивается явление йодизма, сопровождаемое металлическим привкусом во рту, воспалительными процессами на слизистых, появлением угрей, дерматит, нервной возбудимостью. В случае хронической передозировки необходимо отменить лечение.

Взаимодействие

Если проводится одновременное лечение большими дозами йодсодержащего препарата и калийсберегающими диуретиками, у пациента может развиваться гиперкалиемия.

При одновременном употреблении препаратов лития может развиваться гипотиреоз и зоб.

При одновременном приеме тиоционата и перхлората конкурентно тормозится поглощение щитовидной железой йода.

При лечении антитиреоидными препаратами отмечается взаимное ослабление эффекта.

Условия продажи

Отпускается из аптек без рецепта.

Условия хранения

Капли для глаз и раствор нужно хранить при температуре воздуха не более 25° C.

Срок годности

Препарат нужно хранить не более 3 лет.

Особые указания

Если лечение проводится у людей, страдающих почечной недостаточностью, может развиваться гиперкалиемия. Важно регулярно проводить проверку уровня калия в крови. Если лечение проводится в домашних условиях, нужно периодически посещать врача.

Перед началом лечения Калия йодидом необходимо проверить состояние щитовидной железы и исключить наличие злокачественных заболеваний.

Синонимы

Калий йодистый.

Аналоги

Совпадения по коду АТХ 4-го уровня:

Аналогами Калия йодид являются другие йодсодержащие препараты: Йодомарин, Йодбаланс, Йод Витрум и др. Какой именно препарат целесообразно использовать в процессе лечения, должен определить врач.

Йодомарин или Калия йодид: что лучше?

Оба препарата содержат йод и оказывают соответствующее воздействие на организм человека и, соответственно, такие же показания к применению. Отличаются только вспомогательные вещества. Кроме того, Калия йодид – более дешевый препарат.

Детям

Применяется под контролем врача. Важно четко придерживаться указанной дозировки.

При беременности и лактации

При беременности Калия йодид может применяться только в рекомендуемой дозировке. Йод способен проникать через плаценту, поэтому его чрезмерное количество может спровоцировать развитие у плода зоба и гипотиреоза. При беременности перед применением этого препарата нужно обязательно консультироваться с доктором.

Также этот элемент выделяется с грудным молоком. Поэтому если кормящая мама применяет препарат для лечения во время кормления, и при этом доза превышает 1 мг в сутки, у грудничка может развиться гипотиреоз.

Отзывы на Йодид калия

Оставляя отзывы о препарате Калия йодид, люди отмечают, что средство имеет доступную цену, упаковки таблеток хватает на продолжительный период. Йодид калия часто применяется с целью профилактики, однако в отзывах речь идет о  необходимости придерживаться той дозировки, которую назначил врач. В качестве побочных эффектов чаще всего отмечается появление угрей. Важно обязательно проверять состояние щитовидной железы перед лечением, чтобы не усугубить течение заболевания.

Цена Йодида калия, где купить

Купить таблетки, раствор или капли можно в любой аптеке без рецепта. Цена Йодида калия составляет в среднем 140 рублей за 100 таблеток. Цена глазных капель – в среднем 150 рублей.