Immunoprin (Azathioprine)

Azathioprine is used to modulate immune activity in transplant and autoimmune disease settings.

• Organ transplant rejection: helps prevent graft rejection by suppressing immune response.
• Rheumatoid arthritis: reduces joint inflammation and disease progression.
• Systemic lupus erythematosus: controls disease activity and flares.
• Inflammatory bowel disease (Crohn’s disease and ulcerative colitis): maintains remission and reduces inflammatory lesions.

• Azathioprine is a prodrug that is intracellularly converted to 6‑mercaptopurine, which interferes with purine nucleotide synthesis. By inhibiting the formation of DNA and RNA precursors, it blocks proliferation of rapidly dividing T‑ and B‑lymphocytes, thereby dampening cellular and humoral immune responses. The metabolite also incorporates into nucleic acids, causing chain termination, and reduces cytokine production, contributing to overall immunosuppression. These actions collectively limit the activation and clonal expansion of immune cells involved in graft rejection and autoimmune pathology.

Azathioprine may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Nausea: mild gastrointestinal upset.
• Vomiting: occasional episodes.
• Diarrhea: loose stools.
• Decreased white blood cell count: mild leukopenia.
• Elevated liver enzymes: mild hepatic irritation.
• Fatigue: general tiredness.

Serious or Rare Side Effects

• Severe bone marrow suppression: pancytopenia requiring medical attention.
• Hepatotoxicity: significant liver injury.
• Increased risk of infections: opportunistic or severe infections.
• Malignancies: higher incidence of lymphomas and skin cancers.
• Pancreatitis: inflammation of the pancreas.
• Hypersensitivity reactions: rash, fever, or organ involvement.

When prescribing Azathioprine, clinicians should observe several safety precautions.

• Baseline testing: obtain complete blood count and liver function tests before initiation.
• Monitoring: perform regular CBC and liver enzymes during therapy.
• Infection risk: avoid use in patients with active infections.
• Pregnancy: drug is category D; discuss risks with pregnant patients.
• Drug interactions: review concomitant medications that affect bone marrow or liver.
• Store at ambient temperature: keep tablets in original container, protect from moisture and light.

Azathioprine interacts with several medicines that can alter its efficacy or safety.

Major Interactions (Avoid)

• Allopurinol or febuxostat: increase risk of myelosuppression.
• TPMT inhibitors: potentiate toxicity.
• Live vaccines: may cause severe infection.

Moderate Interactions (Monitor Closely)

• Warfarin: may enhance anticoagulant effect.
• ACE inhibitors or ARBs: possible additive renal effects.
• Antacids containing magnesium or aluminum: may reduce absorption.