Cyclophosphamide vs Mycophenolate Mofetil: side effects in FDA adverse event reports
At a glance
| Cyclophosphamide | Mycophenolate Mofetil | |
|---|---|---|
| Drug class | Alkylating Drug | – |
| Brand names | – | – |
| FAERS reports | 175,993 | 32,904 |
| Serious | 96% | 84% |
| Death outcome | 35,641 | 4,489 |
| Boxed warning | No | Yes EMBRYOFETAL TOXICITY, MALIGNANCIES and SERIOUS INFECTIONS Use during pregnancy is associated with increased risks of first trimester pregnancy loss and congenit |
Signals both drugs share
| Reaction | Cyclophosphamide | Mycophenolate Mofetil | Label screen (A / B) |
|---|---|---|---|
| Bk virus infection | 810 · PRR 37.8 | 1,455 · PRR 119.5 | Not in label — unassessed / Labeled adverse reaction |
| Human polyomavirus infection | 132 · PRR 40.4 | 227 · PRR 120.6 | Not in label — unassessed / Labeled (related wording) |
| Acute graft versus host disease in skin | 871 · PRR 54.8 | 1,046 · PRR 94.7 | Not in label — unassessed / Not in label — unassessed |
| Acute graft versus host disease in intestine | 348 · PRR 39.1 | 536 · PRR 95.9 | Not in label — unassessed / Not in label — unassessed |
| Chronic graft versus host disease in skin | 213 · PRR 36.2 | 372 · PRR 107.3 | Not in label — unassessed / Not in label — unassessed |
| Acute graft versus host disease in liver | 180 · PRR 39.4 | 273 · PRR 94.5 | Not in label — unassessed / Not in label — unassessed |
Labeled signals distinctive to Cyclophosphamide
- 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 Mycophenolate Mofetil
- Post transplant lymphoproliferative disorder — n=2,254, PRR 126.8 Labeled (related wording)
- Polyomavirus-associated nephropathy — n=1,473, PRR 272.3 Labeled adverse reaction
- Chronic allograft nephropathy — n=435, PRR 192.7 Labeled (related wording)
- Renal transplant failure — n=425, PRR 117.2 Labeled (related wording)
- Graft loss — n=296, PRR 105.1 Labeled adverse reaction
- Lung transplant rejection — n=251, PRR 94.0 Labeled (related wording)
- Renal graft infection — n=144, PRR 257.5 Labeled (related wording)
- Cytomegalovirus gastrointestinal infection — n=113, PRR 93.8 Labeled (related wording)
Common questions
Which has more reported side effects, Cyclophosphamide or Mycophenolate Mofetil?
Cyclophosphamide has 175,993 FAERS reports and Mycophenolate Mofetil 32,904. 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 84%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Cyclophosphamide and Mycophenolate Mofetil share?
Both drugs carry disproportionality signals for bk virus infection, human polyomavirus infection, acute graft versus host disease in skin, acute graft versus host disease in intestine, chronic graft versus host disease in skin. Shared signals often reflect a shared drug class or the condition both are used for.
Is Cyclophosphamide or Mycophenolate Mofetil 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.