Methimazole (Tapazole)

Endocrinology (Antithyroid Agent)

Dosing & Administration

Adult Dose

Initial: 15-60 mg PO daily divided TID. Maintenance: 5-15 mg daily.

Pediatric Dose

0.4 mg/kg/day PO divided every 8 hours.

Renal Adjustment

No adjustment necessary.

Hepatic Adjustment

Use caution.

Safety & Special Populations

Pregnancy Category

D - Avoid in 1st trimester (use PTU instead); preferred in 2nd/3rd.

Lactation Safety

Compatible (monitor infant thyroid function).

Contraindications & Adverse Effects

Contraindications

  • Hypersensitivity

Common Adverse Effects

  • Agranulocytosis
  • Hepatotoxicity
  • Rash