Carbimazole Tablets

Mechanism

Carbimazole is a prodrug that is rapidly converted into its active metabolite, methimazole. It inhibits thyroid peroxidase enzyme, thereby blocking the iodination of tyrosine residues and the synthesis of thyroid hormones (T3 and T4).

Pharmacokinetics

• Absorption: Rapidly absorbed after oral administration with good bioavailability.
• Distribution: Widely distributed in body tissues, especially in the thyroid gland.
• Metabolism: Converted in the liver to active metabolite methimazole.
• Elimination: Excreted mainly via urine as metabolites.

Side Effects

• Nausea
• Headache
• Skin rash
• Agranulocytosis (rare but serious)
• Hepatic dysfunction

Contraindication

• Hypercalcemia
• Severe renal impairment
• Kidney stones
• Hypersensitivity to any component

Interaction

• Anticoagulants (may enhance effect)
• Beta-blockers
• Theophylline

Warning and Precautions

• Monitor blood counts regularly
• Use cautiously in liver disorders
• Avoid during pregnancy unless necessary