potassium iodide (redirected from ThyroShield)

potassium /po·tas·si·um/ (K) (pah-tas´e-um) chemical element, at. no. 19. Potassium is the chief cation of intracellular fluid, and many of its salts are used as electrolyte replenishers and antihypokalemics, including p. acetate, p. bicarbonate, p. chloride, and p. gluconate. For potassium salts not listed here, see under the active ingredient.

---

potassium bitartrate  a compound administered rectally with sodium bicarbonate to produce carbon dioxide; used for relief of constipation, evacuation of the colon before surgical or diagnostic procedures, and pre- and postpartum bowel emptying.

potassium chloride  an electrolyte replenisher, KCl.

potassium citrate  a systemic and urinary alkalizer, electrolyte replenisher, and diuretic.

dibasic potassium phosphate  the dipotassium salt, K2HPO4; used alone or in combination with other phosphate compounds as an electrolyte replenisher.

potassium hydroxide  an alkalizer used in pharmaceutical preparations.

potassium iodide  a thyroid inhibitor used in the treatment of hyperthyroidism, as a radiation protectant to the thyroid, as an iodine replenisher, and as an antifungal.

monobasic potassium phosphate  the monopotassium salt, KH2PO4; used as a buffering agent in pharmaceutical preparations and, alone or in combination with other phosphate compounds, as an electrolyte replenisher, urinary acidifier, and antiurolithic.

potassium permanganate  the potassium salt of permanganic acid, used as a topical anti-infective, oxidizing agent, and as an antidote for certain poisons.

potassium phosphate  a compound combining potassium and phosphoric acid, usually dibasic potassium phosphate.

---

potassium iodide

n.

A white crystalline compound used as a source of iodine to treat thyrotoxic crisis and to prevent thyroid cancer in the event of overexposure to nuclear radiation. It is also used as an expectorant and antifungal.

---

potassium iodide,

an expectorant.

indications It is prescribed in the treatment of chronic bronchitis, bronchiectasis, asthma, and other pulmonary disease with excess mucus formation and of various thyroid disorders.

contraindications Acute bronchitis, known or suspected pregnancy, or known hypersensitivity to this drug or to any iodide prohibits its use.

adverse effects Among the more serious adverse effects are hypersensitivity, goiter, myxedema, GI disturbance, and skin lesions.

---

potassium

a chemical element, atomic number 19, atomic weight 39.102, symbol K. See Table 6. In combination with other minerals, potassium forms alkaline salts that are important in body processes and play an essential role in maintenance of its acid-base and water balance. All body cells, especially muscle tissue, require a high content of potassium. A proper balance between sodium, calcium and potassium in the blood plasma is necessary for proper cardiac function. Alfalfa meal, molasses and soyabean meal are good sources for herbivores.

---

potassium acetate, bicarbonate, bitartrate, citrate, gluconate

electrolyte replenishers, weak diuretics and urinary alkalinizers. Some are also used as expectorants.

potassium arsenite

see fowler's solution.

potassium bromide

used in the treatment of seizures in humans and dogs.

potassium carbonate

used commercially as a fertilizer.

potassium channel

see channel.

potassium chloride

a compound used orally or intravenously as an electrolyte replenisher.

potassium cyanide

may be present in industrial effluents. A potent cause of cyanide poisoning.

potassium deficiency

nutritional deficiency of potassium is very rare. In calves can cause poor growth, anemia and diarrhea. Experimental deficiency in piglets causes also incoordination and cardiac insufficiency.

potassium exchange resins

an oral preparation administered to limit the amount of potassium available for absorption; used in the management of hyperkalemia. See also ion-exchange resin; sodium polystyrene sulfonate.

potassium guaiacolsulfonate

an expectorant.

potassium hydroxide (syn. potassium hydrate)

used commercially as a caustic. In veterinary medicine used mostly for clearing skin scrapings in the diagnosis of ectoparasite infestation.

potassium iodate

used as a constituent of salt blocks and mixes to supplement the diet with iodine. Overdosing will cause iodism.

potassium iodide

an expectorant and antithyroid agent.

potassium nitrate

used commercially as a fertilizer and a meat preservative. Can cause nitrate poisoning or nitrite poisoning in ruminants.

potassium nitrite

a compound sometimes used in place of potassium nitrate. Overdosing causes methemoglobin formation and severe, sometimes fatal hypoxia.

potassium nutritional deficiency

causes poor growth, anemia and diarrhea in pigs and calves. Electrocardiographic changes are also recorded. See also hypokalemia.

potassium oxalate

causes oxalate poisoning.

potassium permanganate

a topical anti-infective, oxidizing agent, and antidote for many poisons. See also permanganate.

potassium phosphate

a cathartic.

potassium pump

see sodium pump.

potassium sodium tartrate

a compound used as a saline cathartic and also in combination with sodium bicarbonate and tartaric acid (Seidlitz powders, a cathartic).

---

potassium iodide

Iostat, Pima, Thyro-Block, Thyrosafe, ThyroShield

Pharmacologic class: Iodine, iodide

Therapeutic class: Antithyroid agent, expectorant

Pregnancy risk category D

Action

Rapidly inhibits thyroid hormone release, reduces thyroid vascularity, and decreases thyroid uptake of radioactive iodine after radiation emergencies or administration of radioactive iodine isotopes. As expectorant, thought to increase respiratory tract secretions, thereby decreasing mucus viscosity.

Availability

Saturated solution (SSKI): 1 g potassium iodide/ml in 30- and 240-ml bottles

Solution (strong iodine solution, Lugol's solution): 5% iodine and 10% potassium iodide in 120-ml bottle

Syrup: 325 mg potassium iodide/5 ml

Tablets: 130 mg (available only through state and federal agencies)

⊘Indications and dosages

➣ Preparation for thyroidectomy

Adults and children: One to five drops SSKI P.O. t.i.d. or three to six drops strong iodine solution P.O. t.i.d. for 10 days before surgery

➣ Thyrotoxic crisis

Adults and children: 500 mg P.O. (approximately 10 drops SSKI) q 4 hours or 1 ml P.O. (strong iodine solution) t.i.d., at least 1 hour after initial propylthiouracil or methimazole dose

➣ Radiation protectant in emergencies

Adults older than age 40 with predicted thyroid exposure of 500 centigrays (cGy), adults ages 18 to 40 with predicted exposure of 10 cGy, pregnant or breastfeeding women with predicted exposure of 5 cGy, and adolescents weighing 70 kg (154 lb) or more with predicted exposure of 5 cGy: 130 mg P.O. (tablet)

Children ages 3 to 18 (except adolescents weighing 70 kg [154 lb] or more) with predicted thyroid exposure of 5 cGy: 65 mg P.O. (tablet)

Children ages 1 month to 3 years with predicted thyroid exposure of 5 cGy: 32 mg P.O. (tablet)

Infants from birth to age 1 month with predicted thyroid exposure of 5 cGy: 16 mg P.O. (tablet)

➣ Expectorant

Adults: 300 to 650 mg P.O. (SSKI) three or four times daily, given with at least 6 oz of fluid

Children: 60 to 250 mg P.O. (SSKI) q.i.d., given with at least 6 oz of fluid

Off-label uses

• Lymphocutaneous sporotrichosis

Contraindications

• Hypersensitivity to iodine, shellfish, or bisulfites (with some products)
• Hypothyroidism
• Renal impairment
• Acute bronchitis
• Addison's disease
• Acute dehydration
• Heat cramps
• Hyperkalemia
• Tuberculosis
• Iodism
• Concurrent use of potassium-containing drugs, potassium-sparing diuretics, or salt substitutes containing potassium

Precautions

Use cautiously in:
• cystic fibrosis, adolescent acne, hypocomplementemic vasculitis, goiter, autoimmune thyroid disease
• pregnant or breastfeeding patients
• children.

Administration

• Dilute saturated solution with at least 6 oz of water.
☞ Don't give concurrently with other potassium-containing drugs or potassium-sparing diuretics, because of increased risk of hyperkalemia, arrhythmias, and cardiac arrest.
• Know that U.S. government stockpiles potassium iodide 130-mg tablets for emergency use.
• When giving to very young children or patients who can't swallow tablets, crush tablet, dissolve in 20 ml of water, and add 20 ml of selected beverage (such as orange juice).
• Be aware that potassium iodide use as expectorant has been largely replaced by safer and more effective drugs.

Route	Onset	Peak	Duration
P.O.	24 hr	10-15 days	Variable

Adverse reactions

CNS: confusion; unusual fatigue; paresthesia, pain, or weakness in hands or feet

Metabolic: thyroid hyperplasia, goiter (with prolonged use), thyroid adenoma, severe hypothyroidism, hyperkalemia, iodism (with large doses or prolonged use)

Musculoskeletal: weakness and heaviness of legs

Other: tooth discoloration (with strong iodide solution), hypersensitivity reactions including angioedema, fever, cutaneous and mucosal hemorrhage, serum sickness-like reaction

Interactions

Drug-drug. Lithium, other thyroid drugs: additive hypothyroidism

Potassium-sparing diuretics, other potassium preparations: increased risk of hyperkalemia, arrhythmias, and cardiac arrest

Drug-diagnostic tests. Radionuclide thyroid imaging: altered test results

Thyroid uptake of ¹³¹I, ¹²³I, sodium pertechnetate Tc 99m: decreased uptake

Drug-food. Salt substitutes containing potassium: increased risk of hyperkalemia

Patient monitoring

☞ In long-term use, check for signs and symptoms of iodism (metallic taste, sore teeth and gums, sore throat, burning of mouth and throat, coldlike symptoms, severe headache, productive cough, GI irritation, diarrhea, angioedema, rash, fever, and cutaneous or mucosal hemorrhage). Discontinue drug immediately if these occur.
• Monitor potassium level; watch for signs and symptoms of potassium toxicity.
• Assess ECG, renal function, fluid intake and output, and creatinine and blood urea nitrogen levels.
• Monitor thyroid function tests. Watch for evidence of hypothyroidism or hyperthyroidism.

Patient teaching

• Tell patient to dilute in at least 6 oz of water or juice and to take with meals.
• Advise patient to sip strong iodine solution through a straw to help prevent tooth discoloration.
☞ Teach patient to recognize and immediately report signs and symptoms of iodism and potassium toxicity.
• Instruct patient to minimize GI upset by eating small, frequent servings of food and drinking plenty of fluids.
• Inform patient that many salt substitutes are high in potassium. Advise him not to use these without prescriber's approval.
• Caution patient not to take drug if she is pregnant or breastfeeding (except in emergency use).
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.