Comparative Pharmacology
Head-to-head clinical analysis: POTASSIUM IODIDE versus PROPYLTHIOURACIL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: POTASSIUM IODIDE versus PROPYLTHIOURACIL.
POTASSIUM IODIDE vs PROPYLTHIOURACIL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Potassium iodide suppresses thyroid hormone synthesis and release via the Wolff-Chaikoff effect, inhibiting iodide organification and reducing vascularity of the thyroid gland.
Propylthiouracil (PTU) inhibits thyroid peroxidase, thereby blocking the synthesis of thyroid hormones. It also inhibits the peripheral conversion of thyroxine (T4) to triiodothyronine (T3).
Oral: 300 mg (0.3 mL of saturated solution) three times daily for thyroid protection in radiation exposure; for hyperthyroidism preoperative: 60-250 mg (0.06-0.25 mL) three times daily.
Oral, 300-600 mg/day in 3 divided doses until euthyroid; then 50-150 mg/day as maintenance.
None Documented
None Documented
Clinical Note
moderatePropylthiouracil + Clozapine
"The risk or severity of adverse effects can be increased when Propylthiouracil is combined with Clozapine."
Clinical Note
moderateWarfarin + Potassium Iodide
"Warfarin may decrease the anticoagulant activities of Potassium Iodide."
Clinical Note
moderatePhenprocoumon + Potassium Iodide
"Phenprocoumon may decrease the anticoagulant activities of Potassium Iodide."
Clinical Note
moderatePhenindione + Potassium Iodide
Terminal half-life in euthyroid individuals is approximately 13 days (range 10–15 days). In hyperthyroidism, half-life may be shortened to 5–6 days due to increased thyroid clearance; in hypothyroidism, half-life may be prolonged up to 40 days.
Terminal elimination half-life is 1-2 hours in euthyroid patients, but may be prolonged to 2-5 hours in hyperthyroid patients due to altered metabolism and thyroid status. Clinical effect persists longer than half-life due to inhibition of thyroid peroxidase.
Renal: >90% of absorbed iodide is excreted in urine; fecal elimination is negligible (<2%).
Primarily renal (approximately 35% as unchanged drug within 24 hours; remainder as inactive metabolites). Minor biliary/fecal elimination (<5%).
Category C
Category D/X
Antithyroid Agent
Antithyroid Agent
"Phenindione may decrease the anticoagulant activities of Potassium Iodide."