What are the side effects of azathioprine?

How common are serious infections with azathioprine?

Azathioprine suppresses parts of the immune system, raising infection risk. Patients often report bacterial, viral, and fungal infections, ranging from mild respiratory illnesses to life-threatening cases. Some require hospitalization. Clinical reports show higher rates when the drug is combined with other immunosuppressants.

What blood cell changes should patients watch for?

Azathioprine can lower white blood cells, red blood cells, and platelets. This is due to bone marrow suppression. Low counts lead to anemia, increased infection risk, and bleeding problems. Regular blood tests catch these changes before severe symptoms appear.

When does azathioprine cause liver damage?

Liver enzyme elevations appear in some patients. Serious damage occurs rare cases. Doctors monitor liver function blood tests every few weeks at first, then less often once stable. Early signs include fatigue, yellowing skin, or abdominal pain.

What skin cancers and lymphomas are linked to azathioprine?

Long-term azathioprine use raises skin cancer risk, especially squamous cell carcinoma. Lymphoma rates also increase. Sun protection and regular skin checks are recommended. Risk grows with duration of treatment and total dose.

How does azathioprine interact with allopurinol?

Allopurinol blocks azathioprine metabolism, so small doses of azathioprine must be used together. Without proper adjustment, bone marrow suppression can occur much faster. Doctors either avoid the combination or scale down azathioprine by 75 percent.

What happens if a woman takes azathioprine during pregnancy?

Azathioprine crosses the placenta. Some studies show increased premature delivery and low birth weight. Data on malformation rates vary. Women on the drug are advised to use reliable contraception during treatment and for three months afterward.

Can biosimilars or generics of azathioprine change the side effect profile?

Azathioprine has no biosimilars because it is a small-molecule drug. Generic versions exist. Generic quality varies between manufacturers. Some patients report different tolerance when switching brands, but clinical studies show the main side effects remain the same.