Cyclophosphamide For vs Azathioprine: side effects in FDA adverse event reports
At a glance
| Cyclophosphamide For | Azathioprine | |
|---|---|---|
| Drug class | – | Purine Antimetabolite |
| Brand names | Cyclophosphamide | – |
| FAERS reports | 175,993 | 87,582 |
| Serious | 96% | 87% |
| Death outcome | 35,641 | 8,696 |
| Boxed warning | No | Yes - MALIGNANCY Chronic immunosuppression with azathioprine, a purine antimetabolite increases risk of malignancy in humans. Reports of malignancy include post-tra |
Signals both drugs share
No strong shared signal after removing coding and lab terms.
Labeled signals distinctive to Cyclophosphamide For
- Cytomegalovirus infection reactivation — n=1,352, PRR 55.1 Labeled (related wording)
- Cystitis haemorrhagic — n=1,125, PRR 46.1 Labeled (related wording)
- Hepatitis b reactivation — n=791, PRR 39.3 Labeled (related wording)
- Viral haemorrhagic cystitis — n=284, PRR 80.2 Labeled (related wording)
- Secondary immunodeficiency — n=283, PRR 36.8 Labeled (related wording)
- Cystitis viral — n=177, PRR 103.7 Labeled (related wording)
- Ovarian failure — n=143, PRR 42.7 Labeled adverse reaction
- Cystitis bacterial — n=100, PRR 49.4 Labeled (related wording)
Labeled signals distinctive to Azathioprine
- Hepatosplenic t-cell lymphoma — n=155, PRR 171.2 Labeled — boxed warning
- Cholestasis of pregnancy — n=100, PRR 67.0 Labeled adverse reaction
- Lung transplant rejection — n=93, PRR 38.8 Labeled (related wording)
Common questions
Which has more reported side effects, Cyclophosphamide For or Azathioprine?
Cyclophosphamide For has 175,993 FAERS reports and Azathioprine 87,582. More reports does not mean more dangerous: volume follows how widely and how long a drug has been used, prescription vs over-the-counter status, and publicity. The seriousness share (96% vs 87%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Cyclophosphamide For and Azathioprine share?
They share no strong flagged signal after artifacts and lab terms are removed.
Is Cyclophosphamide For or Azathioprine safer?
FAERS cannot answer that: it has no denominator and no comparator. Use this page to see which risks are already on each label and which signals are unlabeled, then check the prescribing information and your clinician for your situation.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, openFDA count queries for seriousness and deaths. Pair chosen because it is a commonly searched comparison. Generated 2026-10-08.