Medicine & USMLE


Musculoskeletal Drugs
  1. Corticosteroids
  2. Acetaminophen
  3. Azathioprine
  4. Sulfasalazine
  5. TNF Inhibitors
  6. Immunosuppressants (Cyclosporine, Mycophenolate, Tacrolimus)
  7. NSAIDs
  8. Colchicine
  9. Allopurinol
  10. Rasburicase
  11. Dantrolene
  12. Muscle Relaxants
  13. Bisphosphonates: Alendronate, Risedronate


Azathioprine is an immunosuppressant drug used to treat autoimmune diseases like lupus and irritable bowel syndrome, among others. Azathioprine is also used to prevent organ transplant rejection. A major side effect to know is bone marrow suppression, which can manifest as a reduction of red blood cells, white blood cells, and platelets.

Key Points

  • Azathioprine (Imuran)
    • Also known as AZA
    • Mechanism
      • Immunosuppressant
        • Purine antimetabolite
          • Blocks purine metabolism and DNA synthesis, suppressing T- and B-lymphocyte proliferation
      • A precursor to the drug 6-MP (6-mercaptopurine)
    • Clinical Uses
      • Autoimmune conditions
        • Systemic Lupus Erythematosus (SLE)
        • Irritable bowel syndrome (IBS)
        • Ulcerative colitis
        • Myasthenia Gravis
      • Prevention of organ transplant rejection
        • Most commonly used post-kidney transplant
    • Side Effects and Adverse Reactions
      • Bone Marrow Suppression
        • Also known as myelosuppression
        • Can lead to anemia (low red blood cells)
        • Can lead to thrombocytopenia (low platelets)
        • Can lead to leukopenia (low white blood cells)
          • Severe, adverse reaction that should be reported to provider
          • Increased when taken with antihypertensives
          • Increased risk of infection
            • Should not receive live vaccines
        • A CBC, including platelet count, should be monitored
      • Nausea and fatigue
      • Hepatotoxicity
        • Liver enzymes should be monitored during treatment