Clonazepam side effects: what 159,258 FDA adverse event reports show
Who reports
159,258 reports · 68% serious · 18,605 with death outcome · 65% female
Used for
Seizure Disorders: Clonazepam tablets are useful alone or as an adjunct in the treatment of the Lennox-Gastaut syndrome (petit mal variant), akinetic, and myoclonic seizures. In patients with absence seizures (petit mal) who have failed to respond to succinimides, clonazepam tablets may be useful. Some loss of effect may occur during the course of clonazepam treatment (see PRECAUTIONS: Loss of Effect ).
What it is
Clonazepam is 1,3-Dihydro-2H-1,4-benzodiazepin-2-one in which the hydrogens at positions 5 and 7 are substituted by 2-chlorophenyl and nitro groups, respectively.
Boxed warning
RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate.
Causality screen of the 40 strongest signals
What the badges mean
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Outcome field, not a reaction Death is a report outcome, not a reaction term. It is dominated by the underlying illness; see the seriousness profile and the boxed warning instead.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only (and, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,140 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Ejection fraction | 218 | 78.3 66.2–92.6ROR 78.4 · calibrated p 8e-7 ✓ | 48.9 EB05 43.7 · IC025 +5.2 3/3 methods agree vs other Benzodiazepines: only this drug | Not in label — unassessed | serious n=218 · ♀ 100% (drug 65%) | not reported in cached trials |
| Sensitisation | 274 | 73.3 63.2–85.0ROR 73.4 · calibrated p 1e-6 ✓ | 46.9 EB05 42.5 · IC025 +5.2 3/3 methods agree vs other Benzodiazepines: PRR 64.9 (47.1–89.5) | Not in label — unassessed | serious n=274 · ♀ 100% (drug 65%) | not reported in cached trials |
| Stubbornness | 151 | 70.0 57.4–85.4ROR 70.1 · calibrated p 2e-6 ✓ | 45.5 EB05 39.7 · IC025 +5.0 3/3 methods agree vs other Benzodiazepines: only this drug | Not in label — unassessed | serious n=149 · ♀ 100% (drug 65%) | not reported in cached trials |
| Asthma-chronic obstructive pulmonary disease overlap syndrome | 119 | 38.8 31.6–47.7ROR 38.9 · calibrated p 7e-5 ✓ | 29.9 EB05 25.7 · IC025 +4.4 3/3 methods agree vs other Benzodiazepines: PRR 5.6 (4.4–6.9) | Not in label — unassessed | serious n=119 · ♀ 100% (drug 65%) · 100% clinician | not reported in cached trials |
| Polycystic ovaries | 302 | 31.2 27.5–35.3ROR 31.2 · calibrated p 2e-4 ✓ | 25.3 EB05 23.0 · IC025 +4.4 3/3 methods agree vs other Benzodiazepines: only this drug | Not in label — unassessed | serious n=293 · ♀ 100% (drug 65%) | not reported in cached trials |
| Nasal oedema | 283 | 24.5 21.6–27.9ROR 24.6 · calibrated p 8e-4 ✓ | 20.7 EB05 18.8 · IC025 +4.1 3/3 methods agree vs other Benzodiazepines: only this drug | Not in label — unassessed | serious n=278 · ♀ 100% (drug 65%) · 100% clinician | not reported in cached trials |
| Cogwheel rigidity | 141 | 20.2 16.9–24.1ROR 20.2 · calibrated p 0.002 ✓ | 17.6 EB05 15.3 · IC025 +3.8 3/3 methods agree vs other Benzodiazepines: PRR 7.8 (6.3–9.7) | Not in label — unassessed | serious n=137 · 100% clinician | not reported in cached trials |
| Psychiatric decompensation | 255 | 19.7 17.2–22.4ROR 19.7 · calibrated p 0.002 ✓ | 17.2 EB05 15.5 · IC025 +3.9 3/3 methods agree vs other Benzodiazepines: PRR 144.3 (89.5–232.7) | Not in label — unassessed | serious n=252 · ♀ 0% (drug 65%) · 100% clinician | not reported in cached trials |
| Agoraphobia | 154 | 16.6 14.0–19.6ROR 16.6 · calibrated p 0.005 ✓ | 14.8 EB05 12.9 · IC025 +3.6 3/3 methods agree vs other Benzodiazepines: PRR 5.3 (4.3–6.4) | Likely indication confounding term in indications | serious n=133 · 100% consumer | not reported in cached trials |
| Rhinitis allergic | 479 | 15.8 14.4–17.4ROR 15.9 · calibrated p 0.006 ✓ | 14.2 EB05 13.1 · IC025 +3.7 3/3 methods agree vs other Benzodiazepines: PRR 14.5 (12.6–16.6) | Labeled (related wording) related wording | serious n=467 · ♀ 100% (drug 65%) | not reported in cached trials |
| Multiple-drug resistance | 327 | 15.5 13.8–17.3ROR 15.5 · calibrated p 0.006 ✓ | 13.9 EB05 12.7 · IC025 +3.6 3/3 methods agree vs other Benzodiazepines: PRR 2.1 (1.9–2.4) | Reporting / coding artifact | serious n=275 · 100% clinician | not reported in cached trials |
| Hypomania | 369 | 14.5 13.1–16.2ROR 14.6 · calibrated p 0.008 ✓ | 13.1 EB05 12.1 · IC025 +3.5 3/3 methods agree vs other Benzodiazepines: PRR 6.6 (5.8–7.5) | Not in label — unassessed | serious n=339 | not reported in cached trials |
| Substance use disorder | 301 | 14.2 12.6–16.0ROR 14.2 · calibrated p 0.009 ✓ | 12.8 EB05 11.7 · IC025 +3.5 3/3 methods agree vs other Benzodiazepines: PRR 1.6 (1.4–1.8) | Labeled adverse reaction exact term | serious n=301 · ♀ 0% (drug 65%) · 100% clinician | not reported in cached trials |
| Drug screen negative | 163 | 13.3 11.3–15.6ROR 13.3 · calibrated p 0.012 ✓ | 12.1 EB05 10.6 · IC025 +3.3 3/3 methods agree vs other Benzodiazepines: only this drug | Reporting / coding artifact | 100% consumer | not reported in cached trials |
| Myoclonic epilepsy | 134 | 13.1 11.0–15.6ROR 13.1 · calibrated p 0.013 ✓ | 11.9 EB05 10.3 · IC025 +3.2 3/3 methods agree vs other Benzodiazepines: PRR 5.8 (4.7–7.2) | Likely indication confounding shares a disease stem with the indications wording | serious n=134 · ♀ 0% (drug 65%) · 100% clinician | not reported in cached trials |
| Drug withdrawal convulsions | 161 | 13.0 11.0–15.2ROR 13.0 · calibrated p 0.013 ✓ | 11.8 EB05 10.3 · IC025 +3.3 3/3 methods agree vs other Benzodiazepines: PRR 2.8 (2.4–3.3) | Not in label — unassessed | serious n=159 · 100% clinician | not reported in cached trials |
| Derealisation | 177 | 11.8 10.1–13.8ROR 11.8 · calibrated p 0.018 ✓ | 10.8 EB05 9.5 · IC025 +3.2 3/3 methods agree vs other Benzodiazepines: PRR 8.0 (6.6–9.8) | Likely indication confounding shares a disease stem with the indications wording | serious n=162 | not reported in cached trials |
| Depersonalisation/derealisation disorder | 131 | 11.6 9.7–13.8ROR 11.6 · calibrated p 0.020 ✓ | 10.6 EB05 9.1 · IC025 +3.1 3/3 methods agree vs other Benzodiazepines: PRR 7.0 (5.6–8.8) | Likely indication confounding shares a disease stem with the indications wording | serious n=123 · ♀ 100% (drug 65%) · 100% consumer | not reported in cached trials |
| Psychomotor skills impaired | 208 | 11.2 9.8–12.9ROR 11.3 · calibrated p 0.022 ✓ | 10.3 EB05 9.2 · IC025 +3.1 3/3 methods agree vs other Benzodiazepines: PRR 5.1 (4.3–6.0) | Not in label — unassessed | serious n=208 · ♀ 0% (drug 65%) · 100% clinician | not reported in cached trials |
| Dissociation | 528 | 9.8 9.0–10.8ROR 9.9 · calibrated p 0.034 ✓ | 9.2 EB05 8.5 · IC025 +3.0 3/3 methods agree vs other Benzodiazepines: PRR 4.7 (4.3–5.2) | Not in label — unassessed | serious n=476 | not reported in cached trials |
| Bipolar i disorder | 149 | 9.5 8.1–11.3ROR 9.6 · calibrated p 0.039 ✓ | 8.8 EB05 7.7 · IC025 +2.9 3/3 methods agree vs other Benzodiazepines: PRR 24.1 (17.9–32.3) | Not in label — unassessed | serious n=133 | not reported in cached trials |
| Pre-existing condition improved | 427 | 9.5 8.6–10.5ROR 9.5 · calibrated p 0.039 ✓ | 8.9 EB05 8.2 · IC025 +3.0 3/3 methods agree vs other Benzodiazepines: PRR 4.3 (3.9–4.9) | Not in label — unassessed | serious n=217 | not reported in cached trials |
| Depression suicidal | 229 | 9.3 8.1–10.6ROR 9.3 · calibrated p 0.042 ✓ | 8.6 EB05 7.7 · IC025 +2.9 3/3 methods agree vs other Benzodiazepines: only this drug | Labeled (related wording) related wording | serious n=226 · ♀ 0% (drug 65%) | not reported in cached trials |
| Tearfulness | 274 | 8.8 7.8–10.0ROR 8.9 · calibrated p 0.049 ✓ | 8.3 EB05 7.5 · IC025 +2.8 3/3 methods agree vs other Benzodiazepines: PRR 7.7 (6.6–9.0) | Not in label — unassessed | serious n=252 · ♀ 37% (drug 65%) | not reported in cached trials |
| Personality disorder | 166 | 8.8 7.5–10.3ROR 8.8 · calibrated p 0.051 | 8.2 EB05 7.2 · IC025 +2.8 3/3 methods agree vs other Benzodiazepines: PRR 5.4 (4.5–6.5) | Not in label — unassessed | serious n=156 | not reported in cached trials |
| Post-traumatic stress disorder | 421 | 8.7 7.9–9.6ROR 8.8 · calibrated p 0.050 | 8.2 EB05 7.6 · IC025 +2.9 3/3 methods agree vs other Benzodiazepines: PRR 4.0 (3.5–4.4) | Not in label — unassessed | serious n=382 | not reported in cached trials |
| Depressive symptom | 219 | 8.7 7.6–10.0ROR 8.7 · calibrated p 0.052 | 8.1 EB05 7.2 · IC025 +2.8 3/3 methods agree vs other Benzodiazepines: PRR 31.9 (24.4–41.7) | Labeled adverse reaction exact term | serious n=209 · ♀ 0% (drug 65%) · 100% clinician | not reported in cached trials |
| Substance abuse | 507 | 8.7 7.9–9.5ROR 8.7 · calibrated p 0.052 | 8.1 EB05 7.6 · IC025 +2.9 3/3 methods agree vs other Benzodiazepines: PRR 1.7 (1.5–1.8) | Reporting / coding artifact | serious PRR 7.4 · ♀ 33% (drug 65%) | not reported in cached trials |
| Bipolar disorder | 658 | 8.4 7.7–9.0ROR 8.4 · calibrated p 0.058 | 7.9 EB05 7.4 · IC025 +2.8 3/3 methods agree vs other Benzodiazepines: PRR 4.7 (4.3–5.2) | Not in label — unassessed | serious PRR 7.0 | not reported in cached trials |
| Completed suicide (death by suicide) | 5,016 | 8.3 8.1–8.5ROR 8.5 · calibrated p 0.055 | 7.8 EB05 7.7 · IC025 +2.9 3/3 methods agree vs other Benzodiazepines: PRR 2.4 (2.3–2.4) | Outcome field, not a reaction boxed warning mentions mortality | age-adj. PRR 6.7 · serious PRR 6.6 · 95% clinician | not reported in cached trials |
| Neuroleptic malignant syndrome | 703 | 8.2 7.6–8.9ROR 8.2 · calibrated p 0.061 | 7.8 EB05 7.3 · IC025 +2.8 3/3 methods agree vs other Benzodiazepines: PRR 1.9 (1.8–2.1) | Not in label — unassessed | age-adj. PRR 6.9 · serious PRR 6.6 · ♀ 40% (drug 65%) | not reported in cached trials |
| Miosis | 459 | 8.0 7.3–8.8ROR 8.0 · calibrated p 0.067 | 7.5 EB05 7.0 · IC025 +2.8 3/3 methods agree vs other Benzodiazepines: PRR 1.5 (1.3–1.6) | Not in label — unassessed | serious PRR 6.7 · ♀ 28% (drug 65%) · 100% clinician | not reported in cached trials |
| Drug use disorder | 477 | 8.0 7.3–8.8ROR 8.0 · calibrated p 0.067 | 7.5 EB05 7.0 · IC025 +2.8 3/3 methods agree vs other Benzodiazepines: PRR 1.3 (1.2–1.4) | Likely indication confounding term in indications; also in warnings | serious PRR 6.2 · ♀ 30% (drug 65%) | not reported in cached trials |
| Tachyphrenia | 196 | 7.8 6.8–9.1ROR 7.8 · calibrated p 0.072 | 7.3 EB05 6.5 · IC025 +2.6 3/3 methods agree vs other Benzodiazepines: PRR 4.1 (3.5–4.9) | Not in label — unassessed | serious n=124 | not reported in cached trials |
| Hostility | 144 | 7.8 6.6–9.2ROR 7.8 · calibrated p 0.075 | 7.2 EB05 6.3 · IC025 +2.6 3/3 methods agree vs other Benzodiazepines: PRR 7.2 (5.8–8.9) | Labeled adverse reaction exact term | serious n=124 | not reported in cached trials |
| Compulsive shopping | 116 | 7.8 6.4–9.4ROR 7.8 · calibrated p 0.075 | 7.2 EB05 6.2 · IC025 +2.5 3/3 methods agree vs other Benzodiazepines: only this drug | Not in label — unassessed | serious n=98 | not reported in cached trials |
| Gambling disorder | 152 | 7.8 6.6–9.1ROR 7.8 · calibrated p 0.075 | 7.2 EB05 6.3 · IC025 +2.6 3/3 methods agree vs other Benzodiazepines: only this drug | Not in label — unassessed | serious n=131 · ♀ 0% (drug 65%) | not reported in cached trials |
| Diabetic neuropathy | 273 | 7.6 6.7–8.6ROR 7.6 · calibrated p 0.079 | 7.1 EB05 6.5 · IC025 +2.6 3/3 methods agree vs other Benzodiazepines: PRR 3.6 (3.1–4.1) | Not in label — unassessed | serious n=260 | not reported in cached trials |
| Sleep apnoea syndrome | 1,048 | 7.6 7.1–8.1ROR 7.6 · calibrated p 0.077 | 7.2 EB05 6.8 · IC025 +2.7 3/3 methods agree vs other Benzodiazepines: PRR 4.6 (4.3–4.9) | Not in label — unassessed | age-adj. PRR 6.6 · serious PRR 6.8 | not reported in cached trials |
| Panic disorder | 210 | 7.5 6.5–8.6ROR 7.5 · calibrated p 0.082 | 7.0 EB05 6.3 · IC025 +2.6 3/3 methods agree vs other Benzodiazepines: PRR 4.9 (4.1–5.7) | Likely indication confounding term in indications; also in warnings | serious n=176 | NCT00282828: 1/63 (1.6%) on Clonazepam (serious AE) |
Clinical concept groups
MedDRA splits one clinical problem across several terms (e.g. "neutropenia", "neutrophil count decreased", "agranulocytosis"), which dilutes term-level signals. These rows count reports with any term in a concept group (an exact union, not a sum), compared with all other drugs. Groups are hand-built and listed in the methods.
| Concept | Reports | PRR 95% CI | Reading |
|---|---|---|---|
| Suicidality | 10,942 | 6.16.0–6.2 | signal |
| Extrapyramidal | 3,629 | 4.74.5–4.8 | signal |
| Depression | 9,426 | 4.54.4–4.6 | signal |
| Seizure | 6,394 | 4.44.3–4.5 | signal |
| Fall / fracture | 7,102 | 2.52.4–2.5 | signal |
| Dependence / withdrawal | 5,140 | 2.32.2–2.4 | signal |
| Rhabdomyolysis / myopathy | 1,370 | 2.22.1–2.4 | signal |
| Hyponatraemia | 1,113 | 1.81.7–1.9 | raised |
| Serious infection | 9,783 | 1.71.6–1.7 | raised |
| Hyperglycaemia / diabetes | 4,128 | 1.61.5–1.6 | raised |
| Pancreatitis | 944 | 1.51.5–1.6 | raised |
| Arrhythmia / qt | 2,089 | 1.41.4–1.5 | raised |
| Tendon disorder | 390 | 1.41.2–1.5 | raised |
| Hypoglycaemia | 955 | 1.31.2–1.4 | raised |
| Venous thromboembolism | 2,013 | 1.21.2–1.3 | raised |
| Kidney injury | 4,169 | 1.21.2–1.2 | raised |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Clonazepam as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (1 of 40 signal terms matched).
- NCT00282828 — Improving Treatment Outcomes in Pharmacotherapy of Generalized Social Anxiety Disorder (N=397, PHASE4; 34 AE terms posted; arms: Sertraline and Clonazepam; Venlafaxine; Sertraline and Placebo)
- NCT02913924 — Effect of Clonazepam on Cannabis Withdrawal and Relapse in Treatment-seeking Patients (N=68, PHASE2; 47 AE terms posted; arms: Clonazepam; Placebo)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Drug ineffective (drug did not work) | 13,989 | 1.4 1.4–1.4ROR 1.4 · calibrated p 0.603 | 1.4 EB05 1.4 · IC025 +0.5 vs other Benzodiazepines: PRR 2.8 (2.7–2.8) | Reporting / coding artifact | age-adj. PRR 1.5 · serious PRR 1.9 | not reported in cached trials |
| Fatigue (tiredness) | 10,474 | 1.8 1.8–1.8ROR 1.8 · calibrated p 0.854 | 1.8 EB05 1.7 · IC025 +0.8 vs other Benzodiazepines: PRR 2.6 (2.6–2.6) | Labeled adverse reaction exact term | age-adj. PRR 1.6 · serious PRR 1.8 | NCT02913924: 2/34 (5.9%) on Clonazepam; 1/34 (2.9%) control |
| Nausea | 9,819 | 1.6 1.6–1.7ROR 1.7 · calibrated p 0.762 | 1.6 EB05 1.6 · IC025 +0.7 vs other Benzodiazepines: PRR 2.4 (2.3–2.4) | Likely indication confounding term in indications; also in warnings | age-adj. PRR 1.4 · serious PRR 1.6 | NCT00282828: 8/63 (12.7%) on Clonazepam; 9/59 (15.3%) control |
| Anxiety | 8,894 | 4.2 4.1–4.3ROR 4.4 · calibrated p 0.312 | 4.1 EB05 4.0 · IC025 +2.0 3/3 methods agree vs other Benzodiazepines: PRR 2.9 (2.9–3.0) | Labeled adverse reaction exact term | age-adj. PRR 3.6 · serious PRR 3.6 | NCT00282828: 3/63 (4.8%) on Clonazepam; 3/59 (5.1%) control |
| Headache | 8,761 | 1.9 1.8–1.9ROR 1.9 · calibrated p 0.890 | 1.8 EB05 1.8 · IC025 +0.8 vs other Benzodiazepines: PRR 2.8 (2.8–2.9) | Labeled adverse reaction exact term | age-adj. PRR 1.6 · serious PRR 2.0 | NCT00282828: 12/63 (19.0%) on Clonazepam; 15/59 (25.4%) control |
| Depression | 8,228 | 4.9 4.8–5.0ROR 5.1 · calibrated p 0.225 | 4.7 EB05 4.7 · IC025 +2.2 3/3 methods agree vs other Benzodiazepines: PRR 3.8 (3.7–3.9) | Labeled — boxed warning exact term | age-adj. PRR 4.0 · serious PRR 4.5 | NCT00282828: 2/63 (3.2%) on Clonazepam; 2/59 (3.4%) control |
| Pain | 8,224 | 1.8 1.7–1.8ROR 1.8 · calibrated p 0.837 | 1.8 EB05 1.7 · IC025 +0.8 vs other Benzodiazepines: PRR 2.6 (2.6–2.7) | Likely indication confounding term in indications; also in warnings | age-adj. PRR 1.8 · serious PRR 1.8 | NCT00282828: 2/63 (3.2%) on Clonazepam; 5/59 (8.5%) control |
| Off label use (used outside approved label) | 8,038 | 1.2 1.2–1.2ROR 1.2 · calibrated p 0.463 | 1.2 EB05 1.2 · IC025 +0.2 vs other Benzodiazepines: PRR 2.3 (2.2–2.3) | Reporting / coding artifact | age-adj. PRR 1.2 · serious PRR 1.3 | not reported in cached trials |
| Dizziness | 7,398 | 2.0 1.9–2.0ROR 2.0 · calibrated p 0.954 | 2.0 EB05 1.9 · IC025 +0.9 vs other Benzodiazepines: PRR 2.8 (2.7–2.8) | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 1.9 | NCT00282828: 6/63 (9.5%) on Clonazepam; 6/59 (10.2%) control |
| Insomnia (trouble sleeping) | 7,120 | 3.6 3.5–3.7ROR 3.7 · calibrated p 0.437 | 3.5 EB05 3.4 · IC025 +1.8 3/3 methods agree vs other Benzodiazepines: PRR 3.1 (3.1–3.2) | Labeled adverse reaction exact term | age-adj. PRR 3.1 · serious PRR 3.5 | NCT00282828: 8/63 (12.7%) on Clonazepam; 25/59 (42.4%) control |
| Dyspnoea (shortness of breath) | 7,072 | 1.7 1.6–1.7ROR 1.7 · calibrated p 0.760 | 1.6 EB05 1.6 · IC025 +0.7 vs other Benzodiazepines: PRR 2.4 (2.4–2.5) | Labeled adverse reaction exact term | age-adj. PRR 1.6 · serious PRR 1.6 | not reported in cached trials |
| Diarrhoea (diarrhea) | 6,807 | 1.4 1.4–1.4ROR 1.4 · calibrated p 0.585 | 1.4 EB05 1.4 · IC025 +0.4 vs other Benzodiazepines: PRR 2.3 (2.2–2.3) | Labeled adverse reaction exact term | age-adj. PRR 1.3 · serious PRR 1.4 | NCT00282828: 7/63 (11.1%) on Clonazepam; 11/59 (18.6%) control |
| Fall | 6,799 | 2.7 2.7–2.8ROR 2.8 · calibrated p 0.693 | 2.7 EB05 2.6 · IC025 +1.4 3/3 methods agree vs other Benzodiazepines: PRR 2.8 (2.7–2.8) | Labeled adverse reaction exact term | age-adj. PRR 2.7 · serious PRR 2.3 | not reported in cached trials |
| Vomiting | 6,549 | 1.9 1.8–1.9ROR 1.9 · calibrated p 0.881 | 1.8 EB05 1.8 · IC025 +0.8 vs other Benzodiazepines: PRR 2.4 (2.4–2.5) | Not in label — unassessed | age-adj. PRR 1.7 · serious PRR 1.9 | NCT02913924: 1/34 (2.9%) on Clonazepam; 1/34 (2.9%) control |
| Malaise (feeling unwell) | 6,157 | 1.9 1.8–1.9ROR 1.9 · calibrated p 0.883 | 1.8 EB05 1.8 · IC025 +0.8 vs other Benzodiazepines: PRR 2.9 (2.8–3.0) | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 1.9 | not reported in cached trials |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Ejection fraction — n=218, PRR 78.3
- Sensitisation — n=274, PRR 73.3
- Stubbornness — n=151, PRR 70.0
- Asthma-chronic obstructive pulmonary disease overlap syndrome — n=119, PRR 38.8
- Polycystic ovaries — n=302, PRR 31.2
- Nasal oedema — n=283, PRR 24.5
- Cogwheel rigidity — n=141, PRR 20.2
- Psychiatric decompensation — n=255, PRR 19.7
- Hypomania — n=369, PRR 14.5
- Drug withdrawal convulsions — n=161, PRR 13.0
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Clonazepam?
In FDA FAERS, the most frequently co-reported reaction terms for Clonazepam are fatigue, nausea, anxiety, headache, depression, pain. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Clonazepam have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate.
Do FAERS signals prove that Clonazepam causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 04db0fbe-7fa3-28af-e063-6294a90abbe6, effective 20240607; matched on
openfda.generic_name.exact:"CLONAZEPAM" AND openfda.product_type:"HUMAN PRESCRIPTION DRUG") - PubChem CID 2802 description (ChEBI)
- Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 1,180 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath - ClinicalTrials.gov API v2 (query
CLONAZEPAM, results-bearing studies sorted by enrollment)
Page generated 2026-10-14. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.