Azathioprine Tab

Immunosuppressive therapy for immune-mediated diseases in dogs including IMHA, IMT, pemphigus, and inflammatory bowel disease. Purine antimetabolite immunosuppressant. Mechanism: converted to 6-mercaptopurine (6-MP) → inhibits purine synthesis and DNA/RNA synthesis → suppresses lymphocyte proliferation (T and B cells). Slow onset (2–6 weeks for full effect). Myelosuppression is primary dose-limiting toxicity. Hepatically activated via TPMT enzyme (genetic variation affects toxicity risk). Key information CYTOTOXIC — handle with care; wear gloves. Do NOT use in cats — severe fatal bone marrow suppression. Dogs: monitor CBC every 2 weeks initially, then monthly. Drug interaction with allopurinol — reduce dose 75%. Teratogenic and carcinogenic potential. Store at room temperature.

Oral tablets: Administer orally. May be given with food to improve compliance and reduce GI upset. Administer with food to reduce GI adverse effects. to reduce GI upset. Wear gloves when handling — cytotoxic immunosuppressant. Do not crush tablets (inhalation risk). Store at room temperature; protect from light. If a dose is missed Administer as soon as you remember. If it is almost time for the next scheduled dose, skip the missed dose and resume the normal schedule. Never double up doses to make up for a missed one. Wear gloves when handling. Complete the prescribed course.

Myelosuppression: leukopenia, thrombocytopenia, anemia (dose-dependent; monitor CBC q2 weeks initially then monthly). GI: vomiting, diarrhea, anorexia, hepatotoxicity. Pancreatitis (rare). Increased infection susceptibility. Cats: severe myelosuppression — use with caution or avoid; thiopurine methyltransferase (TPMT) deficiency in cats increases toxicity risk. Teratogenic.

For animals CATS: Use with extreme caution or avoid — cats have deficient TPMT enzyme activity and are highly susceptible to severe myelosuppression. If used in cats, start at lowest dose and monitor CBC every 1–2 weeks. Dogs: monitor CBC every 2 weeks for first 2 months, then monthly. Monitor liver enzymes with prolonged use. Avoid in pregnant animals. Teratogenic and embryotoxic. Allow 4–6 weeks for full immunosuppressive effect. Avoid live vaccines. Drug interactions: allopurinol markedly increases toxicity. For people handling this medication Wear gloves when handling. Cytotoxic immunosuppressant — wear gloves when handling and do not crush tablets. Wash hands thoroughly with soap and water after handling. Keep out of reach of children. Pregnant women and women of childbearing age should avoid contact. Teratogenic — women of childbearing age must use contraception. Do not handle if pregnant. Keep out of reach of children. Contact Poison Control if ingested.

Contact your veterinarian immediately. Azathioprine overdose causes severe bone marrow suppression, GI signs, and liver toxicity. CBC monitoring required. Do not use in cats. Contact your veterinarian, a veterinary emergency clinic, or the ASPCA Animal Poison Control Center (888-426-4435) immediately. Do not induce vomiting unless specifically directed by a veterinary professional.