Alprazolam vs Clonazepam: side effects in FDA adverse event reports
At a glance
| Alprazolam | Clonazepam | |
|---|---|---|
| Drug class | Benzodiazepine | Benzodiazepine |
| Brand names | – | – |
| FAERS reports | 204,870 | 159,258 |
| Serious | 71% | 68% |
| Death outcome | 33,446 | 18,605 |
| 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 RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids ma |
Signals both drugs share
| Reaction | Alprazolam | Clonazepam | Label screen (A / B) |
|---|---|---|---|
| Drug use disorder | 951 · PRR 13.2 | 477 · PRR 8.0 | Labeled (related wording) / Likely indication confounding |
| Substance use disorder | 283 · PRR 10.3 | 301 · PRR 14.2 | Labeled adverse reaction / Labeled adverse reaction |
| Miosis | 512 · PRR 7.0 | 459 · PRR 8.0 | Not in label — unassessed / Not in label — unassessed |
| Pre-existing condition improved | 409 · PRR 7.0 | 427 · PRR 9.5 | Not in label — unassessed / Not in label — unassessed |
| Panic disorder | 256 · PRR 7.2 | 210 · PRR 7.5 | Likely indication confounding / Likely indication confounding |
Labeled signals distinctive to Alprazolam
- Suicide attempt — n=3,736, PRR 6.6 Labeled (related wording)
- Coma — n=2,872, PRR 6.5 Labeled — boxed warning
- Poisoning — n=1,659, PRR 15.4 Labeled adverse reaction
- Bradyphrenia — n=447, PRR 7.4 Labeled adverse reaction
- Suspected suicide — n=325, PRR 7.4 Labeled (related wording)
- Multiple drug overdose intentional — n=312, PRR 10.7 Labeled (related wording)
- Rebound acid hypersecretion — n=252, PRR 9.1 Labeled (related wording)
- Anxiety disorder — n=199, PRR 6.4 Labeled (related wording)
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
Common questions
Which has more reported side effects, Alprazolam or Clonazepam?
Alprazolam has 204,870 FAERS reports and Clonazepam 159,258. 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 (71% vs 68%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Alprazolam and Clonazepam share?
Both drugs carry disproportionality signals for drug use disorder, substance use disorder, miosis, pre-existing condition improved, panic disorder. Shared signals often reflect a shared drug class or the condition both are used for.
Is Alprazolam or Clonazepam 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.