Eszopiclone side effects: what 25,310 FDA adverse event reports show
Drug class
Not stated in label
Who reports
25,310 reports · 40% serious · 1,683 with death outcome · 66% female
Used for
Eszopiclone tablets are indicated for the treatment of insomnia. In controlled outpatient and sleep laboratory studies, eszopiclone tablets administered at bedtime decreased sleep latency and improved sleep maintenance. The clinical trials performed in support of efficacy were up to 6 months in duration.
What it is
Eszopiclone, USP is a nonbenzodiazepine hypnotic agent that is a pyrrolopyrazine derivative of the cyclopyrrolone class.
Boxed warning
COMPLEX SLEEP BEHAVIORS WARNING: COMPLEX SLEEP BEHAVIORS Complex sleep behaviors including sleep-walking, sleep-driving, and engaging in other activities while not fully awake may occur following use of eszopiclone tablets. Some of these events may result in serious injuries, including death.
Causality screen of the 40 strongest signals
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- 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.
- 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 flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 1,104 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 |
|---|---|---|---|---|---|---|
| Parasomnia | 67 | 87.5 68.1–112.6ROR 87.8 · χ² 5,099 / p <1e-300 | 77.5 EB05 63.1 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=21 | not reported in cached trials |
| Initial insomnia | 856 | 75.9 70.9–81.3ROR 78.5 · χ² 57,854 / p <1e-300 | 69.4 EB05 65.6 · IC025 +6.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=24 · 93% consumer | not reported in cached trials |
| Middle insomnia | 1,216 | 57.9 54.7–61.3ROR 60.8 · χ² 63,520 / p <1e-300 | 54.1 EB05 51.6 · IC025 +5.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.1 · 92% consumer | not reported in cached trials |
| Paradoxical drug reaction | 196 | 46.7 40.4–53.9ROR 47.0 · χ² 8,247 / p <1e-300 | 44.0 EB05 39.1 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | 82% consumer | not reported in cached trials |
| Dysgeusia (altered taste) | 3,854 | 45.1 43.7–46.4ROR 53.0 · χ² 157,855 / p <1e-300 | 42.7 EB05 41.6 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious PRR 3.5 · 83% consumer | NCT00856973: 8/163 (4.9%) on Eszopiclone; 2/161 (1.2%) control |
| Sleep walking | 27 | 40.2 27.3–59.1ROR 40.2 · χ² 946 / p 6e-208 | 37.4 EB05 27.0 · IC025 +3.9 3/3 methods agree | Labeled (related wording) related wording | – | not reported in cached trials |
| Hangover | 113 | 27.3 22.6–32.9ROR 27.4 · χ² 2,746 / p <1e-300 | 26.4 EB05 22.5 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=16 · 87% consumer | not reported in cached trials |
| Anterograde amnesia | 13 | 18.5 10.7–32.1ROR 18.5 · χ² 194 / p 2e-44 | 17.3 EB05 10.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=11 | not reported in cached trials |
| Abnormal sleep-related event | 26 | 16.6 11.2–24.4ROR 16.6 · χ² 357 / p 5e-80 | 15.9 EB05 11.2 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Pre-existing condition improved | 96 | 12.8 10.5–15.6ROR 12.8 · χ² 1,015 / p 4e-223 | 12.5 EB05 10.5 · IC025 +3.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=49 | not reported in cached trials |
| Cataplexy | 21 | 12.3 8.0–19.0ROR 12.4 · χ² 205 / p 1e-46 | 11.4 EB05 7.4 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Insomnia (trouble sleeping) | 3,901 | 12.3 11.9–12.6ROR 14.3 · χ² 40,332 / p <1e-300 | 12.1 EB05 11.8 · IC025 +3.5 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 4.6 · 83% consumer | not reported in cached trials |
| Nephrogenic anaemia | 61 | 10.9 8.5–14.1ROR 11.0 · χ² 534 / p 2e-118 | 10.5 EB05 8.4 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=61 | not reported in cached trials |
| Somnambulism | 84 | 10.7 8.6–13.2ROR 10.7 · χ² 719 / p 1e-158 | 10.4 EB05 8.6 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=57 | not reported in cached trials |
| Hyperparathyroidism secondary | 31 | 10.3 7.2–14.6ROR 10.3 · χ² 247 / p 7e-56 | 9.5 EB05 6.8 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=31 · ♀ 39% (drug 66%) | not reported in cached trials |
| Chronic kidney disease-mineral and bone disorder | 12 | 9.3 5.3–16.5ROR 9.3 · χ² 80 / p 2e-19 | 7.5 EB05 4.4 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious n=12 | not reported in cached trials |
| Sternal fracture | 13 | 8.8 5.1–15.2ROR 8.8 · χ² 82 / p 9e-20 | 7.2 EB05 4.3 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious n=13 | not reported in cached trials |
| Rebound acid hypersecretion | 30 | 8.2 5.7–11.7ROR 8.2 · χ² 180 / p 2e-41 | 7.4 EB05 5.4 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious n=30 | not reported in cached trials |
| Osteosclerosis | 15 | 7.9 4.8–13.2ROR 7.9 · χ² 83 / p 3e-20 | 6.6 EB05 4.2 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Gun shot wound | 17 | 7.5 4.6–12.0ROR 7.5 · χ² 88 / p 3e-21 | 6.4 EB05 4.1 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Stomach discomfort | 45 | 7.2 5.3–9.6ROR 7.2 · χ² 231 / p 2e-52 | 6.7 EB05 5.2 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | 100% consumer | not reported in cached trials |
| Narcolepsy | 16 | 7.1 4.3–11.6ROR 7.1 · χ² 77 / p 9e-19 | 6.0 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious n=12 | not reported in cached trials |
| Drug tolerance | 42 | 6.9 5.1–9.3ROR 6.9 · χ² 204 / p 1e-46 | 6.4 EB05 4.9 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious n=17 | not reported in cached trials |
| Sleep apnoea syndrome | 151 | 6.6 5.6–7.7ROR 6.6 · χ² 705 / p 1e-155 | 6.4 EB05 5.6 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 9.8 | not reported in cached trials |
| Kyphosis | 14 | 6.6 3.9–11.1ROR 6.6 · χ² 60 / p 4e-15 | 5.5 EB05 3.5 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious n=14 | not reported in cached trials |
| Acute sinusitis | 13 | 6.3 3.6–10.9ROR 6.3 · χ² 52 / p 2e-13 | 5.2 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious n=12 | not reported in cached trials |
| Cervical spinal stenosis | 13 | 6.3 3.6–10.8ROR 6.3 · χ² 52 / p 3e-13 | 5.2 EB05 3.2 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious n=13 | not reported in cached trials |
| Snoring | 28 | 6.2 4.3–9.0ROR 6.2 · χ² 116 / p 3e-27 | 5.6 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious n=24 | not reported in cached trials |
| Abnormal dreams | 200 | 6.0 5.2–6.9ROR 6.0 · χ² 823 / p 3e-181 | 5.9 EB05 5.2 · IC025 +2.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.7 · 78% consumer | not reported in cached trials |
| Alcohol use | 25 | 5.6 3.8–8.3ROR 5.6 · χ² 89 / p 2e-21 | 5.1 EB05 3.6 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious n=23 | not reported in cached trials |
| Nightmare | 231 | 5.5 4.9–6.3ROR 5.6 · χ² 850 / p 4e-187 | 5.4 EB05 4.9 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 3.2 | not reported in cached trials |
| Hypertonic bladder | 19 | 5.5 3.5–8.6ROR 5.5 · χ² 65 / p 4e-16 | 4.9 EB05 3.3 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Oral intake reduced | 16 | 5.4 3.3–8.9ROR 5.4 · χ² 53 / p 2e-13 | 4.7 EB05 3.1 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious n=12 | not reported in cached trials |
| Spinal osteoarthritis | 57 | 5.4 4.1–7.0ROR 5.4 · χ² 197 / p 4e-45 | 5.1 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 · 72% consumer | not reported in cached trials |
| Bipolar i disorder | 14 | 5.3 3.1–9.0ROR 5.3 · χ² 45 / p 1e-11 | 4.6 EB05 2.9 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious n=12 | not reported in cached trials |
| Completed suicide (death by suicide) | 537 | 5.3 4.9–5.8ROR 5.4 · χ² 1,872 / p <1e-300 | 5.3 EB05 4.9 · IC025 +2.3 3/3 methods agree | Outcome field, not a reaction boxed warning mentions mortality | serious PRR 7.5 · 94% clinician | not reported in cached trials |
| Suspected suicide | 30 | 5.2 3.7–7.5ROR 5.2 · χ² 98 / p 2e-23 | 4.8 EB05 3.6 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious n=30 · 100% clinician | not reported in cached trials |
| Major depression | 45 | 5.1 3.8–6.9ROR 5.1 · χ² 144 / p 2e-33 | 4.8 EB05 3.8 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 7.0 | not reported in cached trials |
| Breath odour | 15 | 5.1 3.1–8.5ROR 5.1 · χ² 45 / p 8e-12 | 4.4 EB05 2.9 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | – | not reported in cached trials |
| Tachyphrenia | 21 | 5.0 3.3–7.7ROR 5.0 · χ² 64 / p 7e-16 | 4.6 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Eszopiclone 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).
- NCT00856973 — Safety & Efficacy Study of Study Drug (Eszopiclone) in Children and Adolescents With Attention-deficit/Hyperac (N=486, PHASE3; 22 AE terms posted; arms: Pooled High Dose Eszopiclone; Pooled Low Dose Eszopiclone; Placebo)
- NCT00616655 — Generalized Anxiety Disorder Proof of Concept Efficacy and Safety Study of SEP-225441 (Eszopiclone) In GAD Sub (N=456, PHASE2; 18 AE terms posted; arms: Placebo Arm; Eszopiclone Low Dose Arm; Eszopiclone High Dose Arm)
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) | 4,867 | 3.1 3.0–3.1ROR 3.6 · χ² 7,220 / p <1e-300 | 3.1 EB05 3.0 · IC025 +1.6 3/3 methods agree | Reporting / coding artifact | serious PRR 1.1 · 84% consumer | not reported in cached trials |
| Insomnia (trouble sleeping) | 3,901 | 12.3 11.9–12.6ROR 14.3 · χ² 40,332 / p <1e-300 | 12.1 EB05 11.8 · IC025 +3.5 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 4.6 · 83% consumer | not reported in cached trials |
| Dysgeusia (altered taste) | 3,854 | 45.1 43.7–46.4ROR 53.0 · χ² 157,855 / p <1e-300 | 42.7 EB05 41.6 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious PRR 3.5 · 83% consumer | NCT00856973: 8/163 (4.9%) on Eszopiclone; 2/161 (1.2%) control |
| Nausea | 1,417 | 1.5 1.4–1.6ROR 1.5 · χ² 235 / p 2e-53 | 1.5 EB05 1.4 · IC025 +0.5 | Labeled adverse reaction exact term | serious PRR 2.0 | NCT00856973: 4/163 (2.5%) on Eszopiclone; 6/161 (3.7%) control |
| Middle insomnia | 1,216 | 57.9 54.7–61.3ROR 60.8 · χ² 63,520 / p <1e-300 | 54.1 EB05 51.6 · IC025 +5.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.1 · 92% consumer | not reported in cached trials |
| Fatigue (tiredness) | 1,215 | 1.3 1.2–1.4ROR 1.3 · χ² 85 / p 2e-20 | 1.3 EB05 1.2 · IC025 +0.3 | Labeled (related wording) related wording | serious PRR 1.8 | NCT00616655: 4/145 (2.8%) on Eszopiclone; 12/149 (8.1%) control |
| Headache | 1,184 | 1.6 1.5–1.7ROR 1.6 · χ² 250 / p 1e-56 | 1.6 EB05 1.5 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.8 | NCT00856973: 19/163 (11.7%) on Eszopiclone; 19/161 (11.8%) control |
| Dizziness | 890 | 1.5 1.4–1.6ROR 1.5 · χ² 142 / p 5e-33 | 1.5 EB05 1.4 · IC025 +0.5 | Labeled adverse reaction exact term | serious PRR 1.8 | NCT00856973: 6/163 (3.7%) on Eszopiclone; 3/161 (1.9%) control |
| Somnolence (drowsiness) | 888 | 3.7 3.4–3.9ROR 3.8 · χ² 1,732 / p <1e-300 | 3.7 EB05 3.5 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.7 · 72% consumer | NCT00856973: 4/163 (2.5%) on Eszopiclone; 3/161 (1.9%) control |
| Anxiety | 864 | 2.5 2.4–2.7ROR 2.6 · χ² 794 / p 4e-175 | 2.5 EB05 2.4 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.4 | not reported in cached trials |
| Initial insomnia | 856 | 75.9 70.9–81.3ROR 78.5 · χ² 57,854 / p <1e-300 | 69.4 EB05 65.6 · IC025 +6.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=24 · 93% consumer | not reported in cached trials |
| Pain | 826 | 1.1 1.0–1.2ROR 1.1 · χ² 10 / p 0.001 | 1.1 EB05 1.1 · IC025 +0.0 | Labeled adverse reaction exact term | serious PRR 1.8 | NCT00856973: 6/163 (3.7%) on Eszopiclone; 5/161 (3.1%) control |
| Diarrhoea (diarrhea) | 780 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.455 | 1.0 EB05 0.9 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 1.4 | NCT00856973: 4/163 (2.5%) on Eszopiclone; 6/161 (3.7%) control |
| Depression | 721 | 2.6 2.4–2.8ROR 2.7 · χ² 726 / p 4e-160 | 2.6 EB05 2.5 · IC025 +1.3 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 3.5 | not reported in cached trials |
| Fall | 669 | 1.7 1.5–1.8ROR 1.7 · χ² 181 / p 1e-41 | 1.7 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 2.4 | 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.
- Parasomnia — n=67, PRR 87.5
- Paradoxical drug reaction — n=196, PRR 46.7
- Dysgeusia — n=3,854, PRR 45.1 (also seen in trial arm)
- Hangover — n=113, PRR 27.3
- Abnormal sleep-related event — n=26, PRR 16.6
- Cataplexy — n=21, PRR 12.3
- Nephrogenic anaemia — n=61, PRR 10.9
- Somnambulism — n=84, PRR 10.7
- Hyperparathyroidism secondary — n=31, PRR 10.3
- Rebound acid hypersecretion — n=30, PRR 8.2
✓ A hand-written Bradford Hill causality assessment exists for this drug: Eszopiclone ↔ Amnesia.
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 Eszopiclone?
In FDA FAERS, the most frequently co-reported reaction terms for Eszopiclone are insomnia, dysgeusia, nausea, middle insomnia, fatigue, headache. 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 Eszopiclone have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: COMPLEX SLEEP BEHAVIORS WARNING: COMPLEX SLEEP BEHAVIORS Complex sleep behaviors including sleep-walking, sleep-driving, and engaging in other activities while not fully awake may occur following use of eszopiclone tablets. Some of these events may result in serious injuries, including death.
Do FAERS signals prove that Eszopiclone 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 10175591-c1b4-461a-830e-8df982d0d2bf, effective 20250212; matched on
openfda.generic_name.exact:"ESZOPICLONE") - 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, 1,144 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
ESZOPICLONE, results-bearing studies sorted by enrollment)
Page generated 2026-10-08. 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.