৳ 12/unit
Pack: ৳ 120
৳ 12/unit
Pack: ৳ 120
At a glance
Azathioprine is an immunosuppressant used to prevent organ rejection after transplantation and to treat various autoimmune diseases including rheumatoid arthritis, inflammatory bowel disease, and systemic lupus erythematosus.
Indications
- Organ transplantation (kidney, heart, liver) - prevention of rejection
- Severe active rheumatoid arthritis
- Inflammatory bowel disease (Crohn's disease, ulcerative colitis)
- Systemic lupus erythematosus
- Dermatomyositis and polymyositis
- Autoimmune chronic active hepatitis
- Pemphigus vulgaris
- Polyarteritis nodosa
- Autoimmune haemolytic anaemia
- Chronic refractory idiopathic thrombocytopenic purpura
Pharmacology
Azathioprine is an imidazole derivative of 6-mercaptopurine (6-MP). It is rapidly broken down in vivo into 6-MP and a methylnitroimidazole moiety. 6-MP readily crosses cell membranes and is converted intracellularly into a number of purine thioanalogues, which include the main active nucleotide, thioinosinic acid.
Thiopurine S-Methyl Transferase (TPMT) activity is inversely related to red blood cell 6-mercaptopurine derived thioguanine nucleotide concentration. Individuals with TPMT deficiency develop very high cytotoxic thioguanine nucleotide concentrations.
The therapeutic effect of azathioprine may be evident only after several weeks or months of treatment. It is well absorbed from the upper gastrointestinal tract. Plasma levels of azathioprine and 6-mercaptopurine do not correlate well with therapeutic efficacy or toxicity.
Dosage
Transplantation:
- Initial dose: up to 5 mg/kg/day (oral or IV)
- Maintenance: 1-4 mg/kg/day (adjusted according to hematological tolerance)
Other indications (Rheumatoid arthritis, IBD, SLE, etc.):
- Initial dose: 1-3 mg/kg/day
- Maintenance: less than 1 mg/kg/day to 3 mg/kg/day
Special populations:
- Elderly: Start at lower end of dose range
- Renal/hepatic impairment: Consider dose reduction
- Co-administration with allopurinol: Reduce azathioprine dose to 25%
Side effects
- Bone marrow suppression (leukopenia, thrombocytopenia)
- Nausea
- Increased risk of infections (viral, fungal, bacterial)
- Increased bleeding tendency
- Anorexia
- Lymphoproliferative disorders and malignancies (rare)
- Hypersensitivity reactions
- Hepatotoxicity (rare)
Use in pregnancy
[CONSULT YOUR DOCTOR] Azathioprine is unsafe during pregnancy (Category D). May have teratogenic effects on the fetus. Women of reproductive potential should use effective contraception during treatment and for 1 month after the last dose.
Pregnancy Category: D — always consult a doctor before taking during pregnancy.
Precautions & warnings
- Regular blood count monitoring during treatment (weekly for first 8 weeks, then monthly)
- Extreme caution in patients with TPMT enzyme deficiency
- Avoid live vaccines
- Protect skin from sunlight and UV exposure (skin cancer risk)
- Avoid use during pregnancy and breastfeeding
- Men and women of reproductive potential should use effective contraception
Overdose effects
Symptoms: Unexplained infection, throat ulceration, bruising and bleeding (due to bone marrow depression, maximal after 9-14 days). More likely with chronic overdose. A single 7.5 g overdose caused nausea, vomiting, diarrhea, mild leukopenia and mild liver abnormalities.
Treatment: No specific antidote. Close blood count monitoring. Activated charcoal may be effective within 60 minutes. Azathioprine is partially dialysable.
Storage conditions
Store below 25°C. Protect from light.