Ondansetron vs Metoclopramide: side effects in FDA adverse event reports
At a glance
| Ondansetron | Metoclopramide | |
|---|---|---|
| Drug class | Serotonin-3 Receptor Antagonist | – |
| Brand names | – | – |
| FAERS reports | 121,725 | 76,703 |
| Serious | 79% | 89% |
| Death outcome | 15,159 | 9,885 |
| Boxed warning | No | Yes TARDIVE DYSKINESIA Metoclopramide can cause tardive dyskinesia (TD), a serious movement disorder that is often irreversible. There is no known treatment for TD. |
Signals both drugs share
| Reaction | Ondansetron | Metoclopramide | Label screen (A / B) |
|---|---|---|---|
| Neutropenic sepsis | 441 · PRR 11.2 | 376 · PRR 15.1 | Not in label — unassessed / Not in label — unassessed |
| Nephrogenic anaemia | 470 · PRR 19.1 | 289 · PRR 18.0 | Not in label — unassessed / Not in label — unassessed |
| Hyperparathyroidism secondary | 229 · PRR 17.0 | 149 · PRR 17.0 | Not in label — unassessed / Not in label — unassessed |
| Chronic kidney disease-mineral and bone disorder | 142 · PRR 26.1 | 63 · PRR 16.9 | Not in label — unassessed / Not in label — unassessed |
| Lymphoid tissue hypoplasia | 84 · PRR 225.1 | 84 · PRR 358.3 | Not in label — unassessed / Not in label — unassessed |
| Thymus hypoplasia | 82 · PRR 157.3 | 85 · PRR 268.7 | Not in label — unassessed / Not in label — unassessed |
| Disseminated aspergillosis | 88 · PRR 39.6 | 79 · PRR 55.3 | Not in label — unassessed / Not in label — unassessed |
Labeled signals distinctive to Ondansetron
- Serotonin syndrome — n=975, PRR 9.2 Labeled adverse reaction
- Ventricular fibrillation — n=581, PRR 9.4 Labeled (related wording)
- Torsade de pointes — n=465, PRR 10.8 Labeled adverse reaction
- Heart disease congenital — n=201, PRR 10.2 Labeled (related wording)
- Long qt syndrome — n=127, PRR 9.5 Labeled adverse reaction
- Oculogyric crisis — n=107, PRR 9.2 Labeled adverse reaction
Labeled signals distinctive to Metoclopramide
- Tardive dyskinesia — n=16,218, PRR 366.3 Labeled — boxed warning
- Nervous system disorder — n=7,526, PRR 86.5 Labeled adverse reaction
- Movement disorder — n=3,273, PRR 30.8 Labeled — boxed warning
- Dyskinesia — n=3,221, PRR 23.5 Labeled — boxed warning
- Akathisia — n=1,898, PRR 44.1 Labeled adverse reaction
- Parkinsonism — n=614, PRR 18.3 Labeled adverse reaction
- Depression suicidal — n=369, PRR 32.5 Labeled (related wording)
- Grimacing — n=233, PRR 117.0 Labeled adverse reaction
Common questions
Which has more reported side effects, Ondansetron or Metoclopramide?
Ondansetron has 121,725 FAERS reports and Metoclopramide 76,703. 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 (79% vs 89%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Ondansetron and Metoclopramide share?
Both drugs carry disproportionality signals for neutropenic sepsis, nephrogenic anaemia, hyperparathyroidism secondary, chronic kidney disease-mineral and bone disorder, lymphoid tissue hypoplasia. Shared signals often reflect a shared drug class or the condition both are used for.
Is Ondansetron or Metoclopramide 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.