Clonazepam vs Diazepam: side effects in FDA adverse event reports
At a glance
| Clonazepam | Diazepam | |
|---|---|---|
| Drug class | Benzodiazepine | Benzodiazepine |
| Brand names | – | – |
| FAERS reports | 159,258 | 120,964 |
| Serious | 68% | 81% |
| Death outcome | 18,605 | 22,961 |
| Boxed warning | Yes RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids ma | Yes WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS • Concomitant use of benzodiazepines and |
Signals both drugs share
| Reaction | Clonazepam | Diazepam | Label screen (A / B) |
|---|---|---|---|
| Drug use disorder | 477 · PRR 8.0 | 1,142 · PRR 27.6 | Likely indication confounding / Labeled (related wording) |
| Substance use disorder | 301 · PRR 14.2 | 790 · PRR 59.8 | Labeled adverse reaction / Labeled adverse reaction |
| Neuroleptic malignant syndrome | 703 · PRR 8.2 | 807 · PRR 12.6 | Not in label — unassessed / Not in label — unassessed |
| Miosis | 459 · PRR 8.0 | 1,012 · PRR 25.1 | Not in label — unassessed / Not in label — unassessed |
| Hypomania | 369 · PRR 14.5 | 288 · PRR 14.6 | Not in label — unassessed / Not in label — unassessed |
| Agoraphobia | 154 · PRR 16.6 | 171 · PRR 24.6 | Likely indication confounding / Not in label — unassessed |
| Drug withdrawal convulsions | 161 · PRR 13.0 | 143 · PRR 15.0 | Not in label — unassessed / Likely indication confounding |
| Cogwheel rigidity | 141 · PRR 20.2 | 94 · PRR 16.9 | Not in label — unassessed / Not in label — unassessed |
| Depersonalisation/derealisation disorder | 131 · PRR 11.6 | 101 · PRR 11.5 | Likely indication confounding / Not in label — unassessed |
| Asthma-chronic obstructive pulmonary disease overlap syndrome | 119 · PRR 38.8 | 110 · PRR 46.3 | Not in label — unassessed / Not in label — unassessed |
Labeled signals distinctive to Clonazepam
- Rhinitis allergic — n=479, PRR 15.8 Labeled (related wording)
- Depression suicidal — n=229, PRR 9.3 Labeled (related wording)
- Depressive symptom — n=219, PRR 8.7 Labeled adverse reaction
- Hostility — n=144, PRR 7.8 Labeled adverse reaction
Labeled signals distinctive to Diazepam
- Coma — n=3,231, PRR 12.5 Labeled — boxed warning
- Respiratory depression — n=1,038, PRR 16.0 Labeled — boxed warning
- Alcohol interaction — n=127, PRR 12.0 Labeled (related wording)
Common questions
Which has more reported side effects, Clonazepam or Diazepam?
Clonazepam has 159,258 FAERS reports and Diazepam 120,964. 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 (68% vs 81%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Clonazepam and Diazepam share?
Both drugs carry disproportionality signals for drug use disorder, substance use disorder, neuroleptic malignant syndrome, miosis, hypomania. Shared signals often reflect a shared drug class or the condition both are used for.
Is Clonazepam or Diazepam 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.