Diazepam vs Cyclobenzaprine: side effects in FDA adverse event reports
At a glance
| Diazepam | Cyclobenzaprine | |
|---|---|---|
| Drug class | Benzodiazepine | – |
| Brand names | – | Cyclobenzaprine Hydrochloride |
| FAERS reports | 120,964 | 49,555 |
| Serious | 81% | 68% |
| Death outcome | 22,961 | 7,144 |
| Boxed warning | Yes WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS • Concomitant use of benzodiazepines and | No |
Signals both drugs share
| Reaction | Diazepam | Cyclobenzaprine | Label screen (A / B) |
|---|---|---|---|
| Nephrogenic anaemia | 266 · PRR 10.4 | 439 · PRR 43.8 | Not in label — unassessed / Not in label — unassessed |
| Hyperparathyroidism secondary | 153 · PRR 11.1 | 235 · PRR 43.2 | Not in label — unassessed / Not in label — unassessed |
| Asthma-chronic obstructive pulmonary disease overlap syndrome | 110 · PRR 46.3 | 37 · PRR 32.3 | Not in label — unassessed / Not in label — unassessed |
Labeled signals distinctive to Diazepam
- Coma — n=3,231, PRR 12.5 Labeled — boxed warning
- Drug use disorder — n=1,142, PRR 27.6 Labeled (related wording)
- Respiratory depression — n=1,038, PRR 16.0 Labeled — boxed warning
- Substance use disorder — n=790, PRR 59.8 Labeled adverse reaction
- Alcohol interaction — n=127, PRR 12.0 Labeled (related wording)
Labeled signals distinctive to Cyclobenzaprine
- None stood out among the strongest labeled signals.
Common questions
Which has more reported side effects, Diazepam or Cyclobenzaprine?
Diazepam has 120,964 FAERS reports and Cyclobenzaprine 49,555. 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 (81% vs 68%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Diazepam and Cyclobenzaprine share?
Both drugs carry disproportionality signals for nephrogenic anaemia, hyperparathyroidism secondary, asthma-chronic obstructive pulmonary disease overlap syndrome. Shared signals often reflect a shared drug class or the condition both are used for.
Is Diazepam or Cyclobenzaprine 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.