Potassium iodide (drug)

Pharmacological action - replenishing iodine deficiency, antithyroid, mucolytic, expectorant, antifungal, absorbable, radioprotective. When ingested in physiological amounts, iodide normalizes the synthesis of thyroid hormones, triiodothyronine (T3) and thyroxine (T4), which is disturbed due to iodine deficiency , and normalizes the T3 / T4 ratio. In thyroid follicle epithelial cells , under the action of thyroperoxidase, it is oxidized to elemental iodine, which provides iodination of tyrosine residues on the side chains of the thyroglobulin molecule with the formation of thyroid hormone precursors - monoiodotyrosines (MIT) and diiodotyrosines (DITs), which are composed of 140 residues thyroglobulin, only 1/5 part is subjected to iodination. Under the influence of oxidative enzymes, MIT and DIT condense with the formation of thyronins, the main of which are triiodothyronine (T3) and thyroxine (T4). The complex of thyroglobulin with thyronines by endocytosis moves from the colloid to the follicular cell, where it is deposited. The release of thyroid hormones from association with thyroglobulin occurs in the apical part of the thyrocyte by hydrolysis with lysosomal enzymes . As a result of the hydrolysis of thyroglobulin, a number of compounds are released, including triiodothyronine and thyroxine, as well as MIT and DIT. The latter are deodorated inside the gland, and the released iodine is again used for biosynthesis of hormones.

The introduction of a significant excess of iodide (more than 6 mg daily) for hyperthyroidism according to the feedback principle leads to a suppression of the synthesis and release of the thyroid stimulating hormone of the pituitary gland , inhibits the synthesis and release of (predominantly) thyroid hormones, possibly by suppressing the proteolysis of thyroglobulin. In addition, iodide reduces the vascularization and size of the thyroid gland, tightens its tissue, prevents thyroid hyperplasia and restores its size in children and adolescents.

In patients with hyperthyroidism, it quickly causes remission of symptoms, and therefore large doses of iodide are used in the preoperative preparation of patients for thyroid resection to facilitate thyroidectomy (together with other antithyroid drugs) and in thyrotoxic crisis. The antithyroid effect of iodide is unstable - it lasts only 2-3 weeks and is used to temporarily reduce thyroid function.

The radioprotective effect of iodide is due to the fact that it prevents the thyroid gland from absorbing the radioactive isotopes of iodine and protects it from the effects of radiation. When taking potassium iodide at the same time as radiation, the protective effect is about 97%; when taken 12 and 24 hours before exposure to radiation - 90% and 70%, respectively, when taken 1 and 3 hours after exposure - 85% and 50%, more than 6 hours later - the effect is insignificant.

The expectorant effect is due to the fact that iodide, secreted by the bronchial mucous glands, causes reactive hyperemia of the mucosa, promotes liquefaction of sputum, including due to an increase in the secretion of water, enhances the function of ciliated epithelium and increases mucociliary clearance .

There is evidence of the effectiveness of iodide in erythema nodosum and fungal infections.

After oral administration, it is rapidly and completely absorbed in the small intestine and distributed within the intracellular space within 2 hours. It accumulates mainly in the thyroid gland (iodide concentration of more than 500 μg / g of tissue), as well as in the salivary and mammary glands , and the gastric mucosa. It penetrates the placenta well . It is excreted mainly by the kidneys (trace amounts are determined in the urine 10 minutes after ingestion, 80% of the dose is excreted within 48 hours, the rest within 10-20 days), partially with the secrets of the salivary, bronchial , sweat and other glands.

• Prevention of iodine deficiency diseases ( endemic goiter , etc.) in areas with iodine deficiency, including in children, adolescents, pregnant and lactating women, prevention of goiter recurrence after thyroid resection ;
• Treatment of goiter and other iodine deficiency diseases in children (including newborns), adolescents and adults;
• Hyperthyroidism , preparation for thyroid resection, thyrotoxic crisis ;
• Difficult sputum discharge (inflammatory diseases of the upper respiratory tract, bronchial asthma , lung actinomycosis , some forms of aspergillosis );
• Prevention of thyroid absorption of radioactive iodine and protection against radiation ;
• Syphilis (resorption of infiltrates in the tertiary period) - auxiliary treatment;
• In ophthalmology : cataracts , clouding of the cornea and vitreous humor , hemorrhage in the membranes of the eye, fungal lesions of the conjunctiva and cornea ;
• In dentistry : inflammatory diseases of the salivary glands , xerostomia .

Hypersensitivity to iodine, pronounced and latent (for doses exceeding 150 μg / day), thyroid gland hyperfunction, toxic thyroid adenoma, nodular goiter and other benign thyroid tumors (for doses exceeding 300 μg / day, with the exception of preoperative iodine therapy), Dühring's herpetiform dermatitis, pulmonary tuberculosis , nephritis , hemorrhagic diathesis , nephrosis, furunculosis , acne , pyoderma .

Caution

Pregnancy , breastfeeding .

During pregnancy and lactation, it is possible to use only in physiological (preventive) doses. Use during pregnancy can lead to inhibition of thyroid function (hypothyroidism) and increase its size in the fetus, and during breastfeeding - to the appearance of a rash and decrease in thyroid function in the newborn (at doses above 300 mcg iodine per day, breast-feeding should be stopped )

• From the organs of the gastrointestinal tract : nausea , vomiting , dyspeptic symptoms , gastralgia , diarrhea .
• From the nervous system and sensory organs: anxiety, headache .
• Allergic reactions: angioedema , hemorrhages on the skin and mucous membranes, edema of the salivary glands, urticaria .
• Other: changes in thyroid function (hyperthyroidism, hypothyroidism), hyperkalemia , mumps , iodine toxicity (confusion, irregular heart contractions; numbness, tingling, pain or weakness in the hands and feet, unusual lethargy, weakness or heaviness in the legs); iodism (with prolonged use, especially in high doses): burning in the mouth or throat, metallic taste in the mouth, increased salivation, sore teeth and gums, conjunctival redness, swelling of the eyelids , rhinitis , fever , arthralgia , acne, dermatitis (exfoliative, etc. .), eosinophilia .

Overdose

Symptoms of acute overdose: staining of the oral mucosa in brown, rhinitis, bronchitis , gastroenteritis , vocal cord edema, bleeding from the urinary tract , anuria , collapse (up to death).
Treatment of acute overdose: gastric lavage with starch solution (until the blue color of the solution disappears) and 1% sodium thiosulfate solution, the reception of pulp from flour , corn, potato, rice or oat broth, symptomatic and supportive therapy.

The antithyroid effect is enhanced by (mutually) antithyroid drugs. Thyroid-stimulating hormone activates the accumulation of iodine by the thyroid gland, and perchlorate and potassium thiocyanate inhibit it. Taking high doses of iodide simultaneously with potassium - sparing diuretics increases the risk of developing hyperkalemia and arrhythmias . With concomitant use with ACE inhibitors, the risk of developing hyperkalemia also increases, with lithium, the risk of hypothyroidism and the occurrence of goiter.

Inside, after eating, drinking plenty of fluids. Goiter prophylaxis: in 1 dose, for adults and children from 12 years old - 100-200 mcg / day, for newborns and children under 12 years old - 50-100 mcg / day, prevention is carried out for several years, sometimes throughout life; during pregnancy and lactation - 150-200 mcg / day; prevention of recurrence of goiter after resection - 100-200 mcg / day. Treatment of goiter: adults - 200-600 mcg / day, newborns, children and adolescents - 50-200 mcg / day, course of treatment - 6-12 months or more (by decision of the attending physician). As a mucolytic agent: 2-3 tablespoons of a 1-3% solution (0.3-1 g) 3-4 times a day. Treatment of syphilis in the tertiary period: 1 tablespoon of 3% solution 3 times a day. As a radioprotective agent: adults and children over 2 years old - 0.125 g once a day, children under 2 years old - 0.04 g once a day.
Hyperthyroidism: inside, 250 mcg 3 times a day.
In ophthalmology: 1 drop of a 3% solution (eye drops) 3 times a day in the form of conjunctival instillations, the course is 10-15 days.
In dentistry: inside, 1 tablespoon of 0.5-2% solution 3 times a day for 1 month.

Before starting treatment, it is necessary to exclude malignant damage to the thyroid gland. It is used with caution in patients with impaired renal function (periodic monitoring of the level of potassium in the blood is necessary).

Colorless or white cubic crystals or a white crystalline powder of bitter-salty taste, odorless. It absorbs water from moist air well. Easily soluble in water (1: 0.75), alcohol (1:12), glycerin (1: 2.5).

• Description and Specifications of Potassium Iodide