Drug · FAERS side-effect profile with label screen
Acetazolamide side effects: what 5,943 FDA adverse event reports show
Drug class
FDA label (Established Pharmacologic Class) · compare the class
Who reports
5,943 reports · 80% serious · 462 with death outcome · 63% female
openFDA FAERS counts, all years, deduplication not applied
Used for
For adjunctive treatment of: edema due to congestive heart failure; drug-induced edema; centrencephalic epilepsies (petit mal, unlocalized seizures); chronic simple (open-angle) glaucoma, secondary glaucoma, and preoperatively in acute angle-closure glaucoma where delay of surgery is desired in order to lower intraocular pressure.
FDA label, Indications and Usage
What it is
DESCRIPTION Acetazolamide, an inhibitor of the enzyme carbonic anhydrase is a white to faintly yellowish white crystalline, odorless powder, weakly acidic, very slightly soluble in water and slightly soluble in alcohol.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled adverse reaction 7Labeled (related wording) 1Likely indication confounding 2Reporting / coding artifact 4Lab value / disease marker 1Not in label — unassessed 25
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.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- 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. 331 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Intraocular pressure increased (raised eye pressure) | 149 | 41.4 35.3–48.6ROR 42.4 · χ² 5,770 / p <1e-300 | 40.7 EB05 35.5 · IC025 +4.9 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 39.3 | no trial data cached |
| Metabolic acidosis | 206 | 23.1 20.2–26.4ROR 23.9 · χ² 4,312 / p <1e-300 | 22.9 EB05 20.4 · IC025 +4.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 15.9 · 96% clinician | no trial data cached |
| Glaucoma | 85 | 15.6 12.6–19.3ROR 15.8 · χ² 1,145 / p 3e-251 | 15.5 EB05 12.9 · IC025 +3.5 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 12.0 | no trial data cached |
| Arteriosclerosis | 32 | 12.0 8.5–17.0ROR 12.1 · χ² 311 / p 6e-70 | 11.5 EB05 8.3 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 8.8 · ♀ 7% (drug 63%) | no trial data cached |
| Full blood count abnormal | 32 | 10.7 7.6–15.2ROR 10.8 · χ² 272 / p 2e-61 | 10.1 EB05 7.3 · IC025 +2.6 3/3 methods agree | Lab value / disease marker | serious PRR 10.2 · ♀ 0% (drug 63%) | no trial data cached |
| Obstructive airways disorder | 32 | 10.1 7.2–14.3ROR 10.2 · χ² 254 / p 2e-57 | 9.5 EB05 6.8 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 7.5 · ♀ 0% (drug 63%) | no trial data cached |
| Retinal detachment | 26 | 10.0 6.8–14.7ROR 10.0 · χ² 201 / p 6e-46 | 9.2 EB05 6.4 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 7.2 | no trial data cached |
| Vasculitis | 32 | 9.7 6.9–13.7ROR 9.8 · χ² 241 / p 1e-54 | 9.0 EB05 6.5 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 7.2 · ♀ 0% (drug 63%) | no trial data cached |
| Hypokalaemia (low potassium) | 125 | 9.6 8.1–11.5ROR 9.8 · χ² 958 / p 1e-210 | 9.5 EB05 8.1 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.0 · 94% clinician | no trial data cached |
| Drug ineffective for unapproved indication | 140 | 8.9 7.5–10.5ROR 9.1 · χ² 971 / p 2e-213 | 8.7 EB05 7.5 · IC025 +2.8 3/3 methods agree | Reporting / coding artifact | serious PRR 12.7 · 93% clinician | no trial data cached |
| Acute respiratory failure | 44 | 8.1 6.0–10.9ROR 8.2 · χ² 267 / p 2e-60 | 7.6 EB05 5.9 · IC025 +2.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.8 | no trial data cached |
| Toxic epidermal necrolysis (severe skin peeling reaction) | 34 | 8.0 5.7–11.1ROR 8.0 · χ² 200 / p 1e-45 | 7.4 EB05 5.4 · IC025 +2.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.7 · ♀ 32% (drug 63%) · 100% clinician | no trial data cached |
| Drug reaction with eosinophilia and systemic symptoms | 57 | 7.9 6.1–10.2ROR 8.0 · χ² 335 / p 3e-75 | 7.5 EB05 6.0 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 · ♀ 19% (drug 63%) · 100% clinician | no trial data cached |
| Uveitis | 30 | 7.8 5.5–11.2ROR 7.9 · χ² 172 / p 1e-39 | 7.2 EB05 5.2 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 | no trial data cached |
| Sickle cell anaemia with crisis | 35 | 7.8 5.6–10.9ROR 7.9 · χ² 201 / p 5e-46 | 7.2 EB05 5.4 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.8 · ♀ 94% (drug 63%) · 100% clinician | no trial data cached |
| Nodule | 28 | 7.6 5.2–11.0ROR 7.6 · χ² 153 / p 2e-35 | 6.9 EB05 4.9 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 8.4 · ♀ 0% (drug 63%) | no trial data cached |
| Therapy partial responder | 32 | 7.5 5.3–10.6ROR 7.5 · χ² 174 / p 5e-40 | 6.9 EB05 5.1 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 5.7 | no trial data cached |
| Ataxia | 24 | 7.1 4.8–10.6ROR 7.1 · χ² 120 / p 3e-28 | 6.4 EB05 4.5 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.0 · ♀ 39% (drug 63%) · 100% clinician | no trial data cached |
| Hypoxia (low oxygen) | 68 | 6.9 5.4–8.7ROR 6.9 · χ² 334 / p 7e-75 | 6.6 EB05 5.4 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.0 · ♀ 28% (drug 63%) | no trial data cached |
| Sleep disorder due to a general medical condition | 31 | 6.8 4.8–9.6ROR 6.8 · χ² 147 / p 5e-34 | 6.2 EB05 4.6 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 9.3 · ♀ 0% (drug 63%) | no trial data cached |
| Tachypnoea | 25 | 6.5 4.4–9.6ROR 6.5 · χ² 111 / p 3e-26 | 5.9 EB05 4.2 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 · 100% clinician | no trial data cached |
| Electrolyte imbalance | 21 | 6.4 4.2–9.9ROR 6.5 · χ² 91 / p 6e-22 | 5.7 EB05 3.9 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.6 | no trial data cached |
| Clostridium difficile colitis | 19 | 6.3 4.0–9.9ROR 6.3 · χ² 80 / p 2e-19 | 5.5 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | no trial data cached |
| Visual acuity reduced | 59 | 6.2 4.8–8.0ROR 6.3 · χ² 253 / p 2e-57 | 5.9 EB05 4.8 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 · ♀ 38% (drug 63%) | no trial data cached |
| Pulmonary fibrosis | 32 | 5.9 4.2–8.4ROR 5.9 · χ² 126 / p 2e-29 | 5.5 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 · ♀ 0% (drug 63%) | no trial data cached |
| Therapy non-responder | 73 | 5.8 4.6–7.3ROR 5.8 · χ² 284 / p 4e-64 | 5.6 EB05 4.6 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious PRR 6.3 · 93% clinician | no trial data cached |
| Flank pain | 15 | 5.7 3.4–9.4ROR 5.7 · χ² 53 / p 2e-13 | 4.9 EB05 3.1 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Encephalopathy | 39 | 5.6 4.1–7.7ROR 5.7 · χ² 144 / p 2e-33 | 5.3 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.0 · 100% clinician | no trial data cached |
| End stage renal disease | 29 | 5.6 3.9–8.0ROR 5.6 · χ² 104 / p 1e-24 | 5.1 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 · ♀ 26% (drug 63%) | no trial data cached |
| Lung disorder | 77 | 5.6 4.4–6.9ROR 5.6 · χ² 283 / p 7e-64 | 5.4 EB05 4.4 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 | no trial data cached |
| Photophobia (light sensitivity) | 29 | 5.5 3.8–7.9ROR 5.5 · χ² 102 / p 3e-24 | 5.1 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.0 | no trial data cached |
| Paralysis | 22 | 5.4 3.6–8.2ROR 5.4 · χ² 75 / p 3e-18 | 4.9 EB05 3.4 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.0 | no trial data cached |
| Drug resistance | 39 | 5.4 3.9–7.3ROR 5.4 · χ² 134 / p 3e-31 | 5.1 EB05 3.9 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious PRR 4.2 · 95% clinician | no trial data cached |
| Abortion induced | 14 | 5.2 3.1–8.9ROR 5.3 · χ² 44 / p 2e-11 | 4.5 EB05 2.9 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Haemoptysis | 40 | 5.1 3.7–6.9ROR 5.1 · χ² 126 / p 2e-29 | 4.8 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 · ♀ 11% (drug 63%) | no trial data cached |
| Respiratory distress | 39 | 5.0 3.6–6.8ROR 5.0 · χ² 120 / p 3e-28 | 4.7 EB05 3.6 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 · 92% clinician | no trial data cached |
| Grand mal convulsion | 13 | 4.9 2.8–8.4ROR 4.9 · χ² 37 / p 8e-10 | 4.2 EB05 2.7 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 | no trial data cached |
| Eye inflammation | 13 | 4.9 2.8–8.4ROR 4.9 · χ² 36 / p 9e-10 | 4.2 EB05 2.6 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Eye pain | 76 | 4.9 3.9–6.1ROR 4.9 · χ² 229 / p 4e-52 | 4.7 EB05 3.9 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | no trial data cached |
| Hypothyroidism | 43 | 4.8 3.5–6.4ROR 4.8 · χ² 124 / p 4e-29 | 4.5 EB05 3.5 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · ♀ 22% (drug 63%) | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
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 |
|---|---|---|---|---|---|---|
| Off label use (used outside approved label) | 715 | 2.9 2.7–3.1ROR 3.2 · χ² 931 / p 9e-205 | 2.9 EB05 2.7 · IC025 +1.4 3/3 methods agree | Reporting / coding artifact | serious PRR 3.0 | no trial data cached |
| Drug ineffective (drug did not work) | 678 | 1.8 1.7–2.0ROR 1.9 · χ² 265 / p 8e-60 | 1.8 EB05 1.7 · IC025 +0.7 | Reporting / coding artifact | serious PRR 3.2 | no trial data cached |
| Condition aggravated | 286 | 3.3 3.0–3.7ROR 3.5 · χ² 474 / p 2e-105 | 3.3 EB05 3.0 · IC025 +1.5 3/3 methods agree | Reporting / coding artifact | serious PRR 3.4 | no trial data cached |
| Headache | 280 | 1.6 1.4–1.8ROR 1.6 · χ² 60 / p 4e-15 | 1.6 EB05 1.4 · IC025 +0.5 | Labeled adverse reaction exact term | serious PRR 1.8 | no trial data cached |
| Metabolic acidosis | 206 | 23.1 20.2–26.4ROR 23.9 · χ² 4,312 / p <1e-300 | 22.9 EB05 20.4 · IC025 +4.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 15.9 · 96% clinician | no trial data cached |
| Product use in unapproved indication | 204 | 2.9 2.6–3.4ROR 3.0 · χ² 263 / p 2e-59 | 2.9 EB05 2.6 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious PRR 3.4 | no trial data cached |
| Intraocular pressure increased (raised eye pressure) | 149 | 41.4 35.3–48.6ROR 42.4 · χ² 5,770 / p <1e-300 | 40.7 EB05 35.5 · IC025 +4.9 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 39.3 | no trial data cached |
| Somnolence (drowsiness) | 143 | 2.5 2.1–3.0ROR 2.5 · χ² 130 / p 3e-30 | 2.5 EB05 2.2 · IC025 +1.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.5 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 143 | 3.3 2.8–3.9ROR 3.4 · χ² 230 / p 3e-52 | 3.3 EB05 2.9 · IC025 +1.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.4 · ♀ 31% (drug 63%) · 92% clinician | no trial data cached |
| Drug ineffective for unapproved indication | 140 | 8.9 7.5–10.5ROR 9.1 · χ² 971 / p 2e-213 | 8.7 EB05 7.5 · IC025 +2.8 3/3 methods agree | Reporting / coding artifact | serious PRR 12.7 · 93% clinician | no trial data cached |
| Drug interaction | 125 | 2.8 2.3–3.3ROR 2.8 · χ² 142 / p 6e-33 | 2.8 EB05 2.4 · IC025 +1.2 3/3 methods agree | Reporting / coding artifact | serious PRR 2.1 · 90% clinician | no trial data cached |
| Hypokalaemia (low potassium) | 125 | 9.6 8.1–11.5ROR 9.8 · χ² 958 / p 1e-210 | 9.5 EB05 8.1 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.0 · 94% clinician | no trial data cached |
| Paraesthesia (tingling/numbness) | 119 | 2.7 2.2–3.2ROR 2.7 · χ² 123 / p 8e-29 | 2.6 EB05 2.3 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.2 | no trial data cached |
| Visual impairment | 114 | 3.3 2.7–3.9ROR 3.3 · χ² 178 / p 5e-41 | 3.2 EB05 2.8 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 | no trial data cached |
| Hypotension (low blood pressure) | 112 | 2.0 1.6–2.4ROR 2.0 · χ² 53 / p 1e-13 | 2.0 EB05 1.7 · IC025 +0.7 | Not in label — unassessed | serious PRR 1.6 | no trial data cached |
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.
- Arteriosclerosis — n=32, PRR 12.0
- Obstructive airways disorder — n=32, PRR 10.1
- Retinal detachment — n=26, PRR 10.0
- Vasculitis — n=32, PRR 9.7
- Drug reaction with eosinophilia and systemic symptoms — n=57, PRR 7.9
- Uveitis — n=30, PRR 7.8
- Sickle cell anaemia with crisis — n=35, PRR 7.8
- Nodule — n=28, PRR 7.6
- Hypoxia — n=68, PRR 6.9
- Sleep disorder due to a general medical condition — n=31, PRR 6.8
✓ A hand-written Bradford Hill causality assessment exists for this drug: Acetazolamide ↔ Metabolic acidosis.
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 Acetazolamide?
In FDA FAERS, the most frequently co-reported reaction terms for Acetazolamide are headache, metabolic acidosis, intraocular pressure increased, somnolence, acute kidney injury, hypokalaemia. 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 Acetazolamide have an FDA boxed warning?
No. The FDA label retrieved for Acetazolamide has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Acetazolamide 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 0700a910-79aa-4431-aecf-637fe14fcae8, effective 20260512; matched on
openfda.generic_name.exact:"ACETAZOLAMIDE") - 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, 371 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
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.