Pima, SSKI, Thyro-Block
Classifications: antithyroid agent; expectorant; Therapeutic: antithyroid; expectorant
Pregnancy Category: D
325 mg/5 mL syrup; 1 g/mL solution
Pharmacologic use primarily related to iodide portion of molecule. Appears to increase secretion of respiratory fluids by
direct action on bronchial tissue, thereby decreasing mucus viscosity. If patient is euthyroid, excess iodide ions causes
minimal change in thyroid gland mass. Conversely, when the thyroid gland is hyperplastic, excess iodide ions temporarily
inhibit secretion of thyroid hormone, foster accumulation in thyroid follicles, and decrease vascularity of gland.
Potassium iodide administration for hyperthyroidism is limited to short-term therapy. As an expectorant, the iodine ion
increases mucous secretion formation in the bronchi, and decreases viscosity of the mucus.
To facilitate bronchial drainage and cough in emphysema, asthma, chronic bronchitis, bronchiectasis, and respiratory tract
allergies characterized by difficult-to-raise sputum. Also used alone for hyperthyroidism or in conjunction with antithyroid
drugs and propranolol in treatment of thyrotoxic crisis; in immediate preoperative period for thyroidectomy to decrease
vascularity, fragility, and size of thyroid gland and for treatment of persistent or recurring hyperthyroidism that occurs
in Graves' disease patients. Used as a radiation protectant in patients receiving radioactive iodine and to shield the thyroid
gland from radiation in the wake of a serious nuclear plant accident. (Use as an expectorant has been largely replaced by
Hypersensitivity or idiosyncrasy to iodine; hyperthyroidism; hyperkalemia; acute bronchitis; pregnancy (category D), lactation.
Renal impairment; cardiac disease; pulmonary tuberculosis; Addison's disease.
Route & Dosage
|To Reduce Thyroid Vascularity
Adult/Child: PO 50250 mg t.i.d. for 1014 d before surgery
Adult: PO 300650 mg p.c. b.i.d. or t.i.d.
Child: PO 60250 mg p.c. b.i.d. or t.i.d.
Thyroid Blocking in Radiation Emergency
Adult: PO 130 mg/d for 10 d
Child: PO <1 y, 65 mg/d for 10 d; >1 y, 130 mg/d for 10 d
- Give with meals in a full glass (240 mL) of water or fruit juice and at bedtime with food or juice to disguise salty taste
and minimize gastric distress.
- Avoid giving KI with milk; absorption of the drug may be decreased by dairy products.
- Adhere strictly to schedule and accurate dose measurements when iodide is administered to prepare thyroid gland for surgery,
particularly at end of treatment period when possibility of "escape" (from iodide) effect on thyroid gland increases.
- Place container in warm water and gently agitating to dissolve if crystals are noted in the solution.
- Discard any solution that has turned a brownish yellow on standing, especially if exposed to light (caused by liberated
trace of free iodine).
- Store in airtight, light-resistant container.
Adverse Effects (≥1%)GI: Diarrhea
, nausea, vomiting, stomach pain, nonspecific small bowel lesions (associated with enteric
coated tablets). Body as a Whole: Angioneurotic edema, cutaneous
and mucosal hemorrhage, fever, arthralgias, lymph
node enlargement, eosinophilia, paresthesias, periorbital edema,
weakness. Iodine poisoning (iodism):
Metallic taste, stomatitis
, salivation, coryza, sneezing; swollen and tender salivary glands (sialadenitis), frontal headache,
vomiting (blue vomitus if stomach contained starches, otherwise yellow vomitus), bloody diarrhea
Hyperthyroid adenoma, goiter
, hypothyroidism, collagen diseaselike syndromes. CV:
Irregular heartbeat. CNS:
Mental confusion. Skin:
Acneiform skin lesions (prolonged use), flare-up of adolescent acne
Productive cough, pulmonary
Diagnostic Test Interference
Potassium iodide may alter thyroid function test results and may interfere with urinary 17-OHCS determinations.
InteractionsDrug: antithyroid drugs
may potentiate hypothyroid and goitrogenic actions; potassium-sparing diuretics
, potassium supplements
, ace inhibitors
increase risk of hyperkalemia.
Adequately absorbed from GI tract. Distribution:
Crosses placenta. Elimination:
Cleared from plasma
excretion or thyroid
Assessment & Drug Effects
- Lab tests: Determine serum potassium levels before and periodically during therapy.
- Keep physician informed about characteristics of sputum: quantity, consistency, color.
Patient & Family Education
- Report to physician promptly the occurrence of GI bleeding, abdominal pain, distension, nausea, or vomiting.
- Report clinical S&S of iodism (see ADVERSE EFFECTS). Usually, symptoms will subside with dose reduction and lengthened intervals between doses.
- Avoid foods rich in iodine if iodism develops: Seafood, fish liver oils, and iodized salt.
- Be aware that sudden withdrawal following prolonged use may precipitate thyroid storm.
- Do not use OTC drugs without consulting physician. Many preparations contain iodides and could augment prescribed dose [e.g.,
cough syrups, gargles, asthma medication, salt substitutes, cod liver oil, multiple vitamins (often suspended in iodide
- Be aware that optimum hydration is the best expectorant when taking KI as an expectorant. Increase daily fluid intake.