Azatiopirin / Merkaptopürin

Clinical Effects:

  • OVERDOSE: Nausea, vomiting, diarrhea, delayed leukopenia, increased SGOT and bilirubin, and impaired renal function can occur in overdose. ADVERSE EFFECTS: Fever, hepatitis, pancreatitis, skin rashes, and alopecia have developed Myelosuppression is the dose-limiting toxicity.

Range of Toxicity:

  • TOXICITY: A toxic dose has not been established. ADULT: An adult developed transient neutropenia after ingesting azathioprine 7500 mg. CHILD: Transient neutropenia occurred in a 22-month-old child following ingestion of 1 g of 6-mercaptopurine (86 mg/kg). A 30-month-old child developed elevated liver enzymes following ingestion of 400 mg (500 mg/m(2)) of 6-MP. THERAPEUTIC DOSE: ADULT: Azathioprine: 1 to 5 mg/kg/day orally. 6-mercaptopurine: 1.5 to 2.5 mg/kg/day orally as a single dose. PEDIATRIC: Azathioprine: Safety and efficacy not established. 6-mercaptopurine: 1.5 to 2.5 mg/kg/day as a single dose, usually in combination with methotrexate.


  • Decontamination: Activated charcoal
  • Support: Care is symptomatic and supportive.
  • Neutropenia: Severe neutropenia: filgrastim 5 mcg/kg/day subcutaneously, or sargramostim 250 mcg/m(2)/day infused over 4 hrs.
  • Enhanced elimination procedure: Azathioprine and metabolites are hemodialyzable
  • Monitoring of patient: Serial CBC with differential due to possible delayed neutropenia, hepatic enzymes and renal function