Comparative Pharmacology
Head-to-head clinical analysis: IOSAT versus PROPYLTHIOURACIL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: IOSAT versus PROPYLTHIOURACIL.
IOSAT vs PROPYLTHIOURACIL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Blocks thyroidal uptake of radioactive iodine isotopes, reduces thyroid exposure to radiation by saturating thyroid gland with stable iodine.
Propylthiouracil (PTU) inhibits thyroid peroxidase, thereby blocking the synthesis of thyroid hormones. It also inhibits the peripheral conversion of thyroxine (T4) to triiodothyronine (T3).
Adults: 130 mg orally once daily for potassium iodide (SSKI 1 g/mL). For thyroid protection in radiation exposure: 130 mg orally once, may repeat after 24 hours if necessary.
Oral, 300-600 mg/day in 3 divided doses until euthyroid; then 50-150 mg/day as maintenance.
None Documented
None Documented
3-5 days in euthyroid individuals; prolonged in hyperthyroidism (6-12 days) and renal impairment (up to 30 days)
Clinical Note
moderatePropylthiouracil + Clozapine
"The risk or severity of adverse effects can be increased when Propylthiouracil is combined with Clozapine."
Clinical Note
moderateWarfarin + Propylthiouracil
"Warfarin may decrease the anticoagulant activities of Propylthiouracil."
Clinical Note
moderatePhenprocoumon + Propylthiouracil
"Phenprocoumon may decrease the anticoagulant activities of Propylthiouracil."
Clinical Note
moderatePhenindione + Propylthiouracil
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: >99% as iodide; fecal/biliary: <1%
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 Propylthiouracil."