Iodine GPO

Iodine GPO

iodine

Manufacturer:

GPO

Distributor:

GPO
Full Prescribing Info
Contents
Iodine.
Description
Each tablet contains Iodine 0.15 mg (as potassium iodide 0.196 mg).
Action
Pharmacology: Pharmacodynamics: Iodine is an essential component of the thyroid hormones, triiodothyronine (T3) and thyroxine (T4), and is therefore essential for normal thyroid function. The thyroid gland traps iodine from the blood and incorporates it into thyroid hormones that are stored and released into the circulation. In target tissues, T3, the physiologically active thyroid hormone, can bind to thyroid receptors in the nuclei of cells and regulate gene expression. In target tissues, T4, the most abundant circulating thyroid hormone, can be converted to T3 by selenium-containing enzymes known as deiodinases. In this manner, thyroid hormones regulate a number of physiologic processes, including growth, development, metabolism, and reproductive function.
Pharmacokinetics: Potassium iodide is well absorbed and enters in the circulation in the form of iodide, which is actively transported and concentrated by the thyroid gland.
Indications/Uses
Prevent the iodine deficiency in pregnant women, which could have adverse effects in all stages of development but is most damaging to the developing brain and to regulating many aspects of growth and development.
Dosage/Direction for Use
For pregnant women and breast feeding, orally administered 1 tablet once daily or by physician prescribed.
Overdosage
Acute iodine poisoning: Acute poisoning is rare and usually occurs only with doses of many grams. Symptoms of acute iodine poisoning include burning of the mouth, throat, and stomach; fever; nausea: vomiting; diarrhea; a weak pulse; and coma.
Chronic toxicity: Chronic toxicity may develop when intake is >1.1 mg/day. Most people who ingest excess amounts of iodine remain euthyroid. Some people who ingest excess amounts of iodine, particularly those who were previously deficient, develop hyperthyroidism. Paradoxically, excess uptake of iodine by the thyroid may inhibit thyroid hormone synthesis. Thus, iodine toxicity can eventually cause iodine goiter, hypothyroidism, or myxedema. Very large amount of iodine may cause a brassy taste in the mouth, increased salivation, GI irritation, and acneiform skin lesions. Patients exposed to frequent large amounts of radiographic contrast dyes or the drug amiodarone also need to have their thyroid function monitored. Diagnosis is usually based on thyroid function and imaging test findings, which are correlated with clinical data. Iodine excretion may be more specific but is not usually measured.
Treatment: Acute poisoning: Gastric lavage with soluble starch solution (15 g cornstarch or flour in 500 ml water) is recommended for removing iodine from the stomach. A 1% oral solution of thiosulfate is a specific antidote, as it will reduce iodine to iodide. Milk can help relive gastric irritation. Correct fluid and electrolyte imbalance and treat shock if necessary.
Chronic poisoning: Discontinue use of iodine and iodides. High sodium chloride intake will speed recovery. For iodism characterized by skin or mucous membrane reactions, give cortisone or equivalence corticosteroid 25 to 100 mg every 6 hours orally until symptoms abate.
Contraindications
Iodide preparations are contraindicated in patient with known sensitivity potassium iodide or any component of the formulation.
Warnings
(based on the Ministry of Public Health Announcement): Discontinue the drug and consult the physician immediately if there is skin rashes, abdominal pain, vomiting, respiratory discomfort.
Special Precautions
In iodine deficiency: Iodine supplementation programs in iodine-deficient populations have been associated with an increased incidence of iodine-induced hyperthyroidism (IHH), mainly in older people and those with multinodular goiter. Iodine intakes of 0.15-0.20 mg/day have been found lo increase the incidence of IHH in iodine-deficient populations. Iodine deficiency increases the risk of developing autonomous thyroid nodules that are unresponsive to the normal thyroid regulation system, resulting in hyperthyroidism after iodine supplementation. IHH is considered by some experts to be an iodine deficiency disorder. In general, the large benefit of iodization programs outweighs the small risk of IHH in iodine-deficient populations.
In iodine sufficiency: In iodine-sufficient populations excess iodine intake is most commonly associated with elevated blood levels of thyroid stimulating hormone (TSH), hypothyroidism, and goiter. In iodine-sufficient adults, elevated TSH levels have been found at iodine intakes between 1.70 and 1.80 mg/day. A tolerable upper level of intake (UL) for iodine for adults is 1.10 mg/day. Very high pharmacologic doses of iodine may also produce thyroid enlargement (goiter) due to increased TSH stimulation of the thyroid gland. Prolonged intakes of more than 18 mg/day have been found to increase the incidence of goiter. The UL values for iodine are listed by age group in the table as follows. The UL is not meant lo apply to individuals who are being treated with iodine under medical supervision. (See table.)

Click on icon to see table/diagram/image

Individuals with increased sensitivity to excess iodine intake: Individuals with iodine deficiency, nodular goiter, or autoimmune thyroid disease may be sensitive to intake levels considered safe for the general population and may not be protected by the UL for iodine intake. Children with cystic fibrosis may also be more sensitive to the adverse effects of excess iodine.
Excess iodine and thyroid cancer: Observational studies have found increased iodine intake to be associated with an increased incidence of thyroid papillary cancer. The reasons for this association are not clear. In populations that were previously iodine deficient, salt iodization programs have resulted in relative increases in thyroid papillary cancers and relative decreases in thyroid follicular cancers. In general, thyroid papillary cancers are less aggressive and have a better prognosis than thyroid follicular cancers.
Use In Pregnancy & Lactation
The Recommended Dietary Allowance (RDA) for iodine of pregnancy and breast feeding are 0.22 and 0.29 mg/day, respectively. Therefore, the recommended dose is safe.
Do not take more than 1.10 mg of iodine per day if the patient is over 18 years old; do not take more than 900 mcg of iodine per day if the patient is 14 to 18 years old. Higher intake might cause thyroid problems.
Adverse Reactions
Iodine is likely safe for most people when taken by mouth at recommended amounts. Therefore, iodine can cause significant side effects in some people. Common side effects include nausea and stomach pain, runny nose, headache, metallic taste, and diarrhea. In sensitive people iodine can cause side effects including swelling of the lips and face (angioedema), severe bleeding and bruising, fever, joint pain, lymph node enlargement, allergic reactions including hives, and death.
In both children and adults,there is concern that higher intake can increase the risk of side effects such as thyroid problems. Iodine in larger amounts can cause metallic taste, soreness of teeth and gums, burning in the mouth and throat, increased saliva, throat inflammation, stomach upset, diarrhea, wasting, depression, skin problems, and many other side effects. When iodine is used directly on the skin, it can cause skin irritation, stains, allergic reactions, and other side effects.
Drug Interactions
Amiodarone: a medication used to prevent abnormal heart rhythms, contains high levels of iodine and may affect thyroid function.
Medications used to treat hyperthyroidism: such as propylthiouracil (PTU) and methimazole, may increase the risk of hypothyroidism.
Lithium: The use of lithium in combination with pharmacologic doses of potassium iodide may result in hypothyroidism.
Warfarin: The use of pharmacologic doses of potassium iodide may decrease the anticoagulant effect of warfarin (coumarin).
Medications for high blood pressure: Angiotensin-converting enzyme (ACE) inhibitors: such as benazepril, lisinopril and fosinopril are used preliminary to treat high blood pressure. Taking potassium iodide with ACE inhibitors can increase the risk of hyperkalemia (elevated blood level of potassium).
Angiotensin receptor blockers (ARBs): Some medications for high blood pressure might decrease how quickly the body gets rid of potassium. Most iodine supplements contain potassium. Taking potassium iodide along with some medications for high blood pressure might cause too much potassium in the body. Do not take potassium iodide if taking medications for high blood pressure. The ARBs include losartan, valsartan, irbesartan, candesartan, telmisartan, and eprosartan.
Potassium-sparing diuretics: Taking potassium iodide with potassium-sparing diuretics, such as spironolactone and amiodarone can increase risk of hyperkalemia.
Food or dietary supplement: Selenium deficiency can exacerbate the effects of iodine deficiency. Iodine is essential for the synthesis of thyroid hormone, but selenium­-dependent enzymes (iodothyronine delodinases) are also required for the conversion of thyroxine (T4) to the biologically active thyroid hormone, triiodothyronine (T3). Additionally, deficiencies of vitamin A or iron may exacerbate the affects of iodine deficiency.
Storage
Store below 30°C.
ATC Classification
V06D - OTHER NUTRIENTS ; Used as general nutrients.
Presentation/Packing
Tab (white, circular, biconvex) 150 mcg x 60's.
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