เมทิมะโซล

Key Facts

• Blocks thyroid hormone production; takes 3-4 weeks to show effect on blood tests
• Available as tablets, flavored liquid, or transdermal ear gel
• Carbimazole (used in UK/Australia) converts to methimazole in the body
• Side effects (15% of cats): lethargy, appetite loss, vomiting; usually resolve with dose adjustment
• Serious side effects (rare): facial itching (<4%), liver toxicity (<2%), bone marrow changes (<4%)
• Most side effects occur in first 3 months of therapy
• Hazardous to humans; gloves recommended when handling; pregnant women must avoid contact
• Does not shrink the thyroid nodule; tumor may grow over time and become resistant
• Treating hyperthyroidism may unmask underlying chronic-kidney-disease
• Transdermal gel: lower GI side effects but slower to achieve control (67% vs 82% at 4 weeks)
• radioactive-iodine-therapy is the gold standard; methimazole is often used as a bridge or when I-131 is unavailable
• Species: cats