Drug · FAERS side-effect profile with label screen
Atovaquone Oral Suspension side effects: what 6,709 FDA adverse event reports show
Drug class
Antimalarial, Antiprotozoal
FDA label (Established Pharmacologic Class)
Who reports
6,709 reports · 88% serious · 1,158 with death outcome · 42% female
openFDA FAERS counts, all years, deduplication not applied
Used for
------------------- INDICATIONS AND USAGE -------------------- Atovaquone oral suspension is a quinone antimicrobial drug indicated for: Prevention of Pneumocystis jirovecii pneumonia (PCP) in adults and adolescents aged 13 years and older who cannot tolerate trimethoprim-sulfamethoxazole (TMP-SMX).
FDA label, Indications and Usage
What it is
11 DESCRIPTION Atovaquone oral suspension, USP is a quinone antimicrobial drug.
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 3Labeled (related wording) 1Likely indication confounding 2Reporting / coding artifact 2Not in label — unassessed 32
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.
- 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. 275 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 |
|---|---|---|---|---|---|---|
| Pneumocystis jirovecii pneumonia | 148 | 46.9 40.0–55.1ROR 48.0 · χ² 6,512 / p <1e-300 | 46.0 EB05 40.1 · IC025 +5.1 3/3 methods agree | Likely indication confounding term in indications | serious PRR 30.4 | no trial data cached |
| Thrombotic microangiopathy | 89 | 29.0 23.5–35.6ROR 29.3 · χ² 2,353 / p <1e-300 | 28.5 EB05 23.9 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 18.8 · 97% clinician | no trial data cached |
| Hepatic cytolysis | 105 | 27.1 22.4–32.7ROR 27.5 · χ² 2,588 / p <1e-300 | 26.7 EB05 22.7 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 17.6 · 99% clinician | no trial data cached |
| Cytokine release syndrome | 118 | 19.5 16.3–23.3ROR 19.8 · χ² 2,037 / p <1e-300 | 19.3 EB05 16.5 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 12.6 · 97% clinician | no trial data cached |
| Agranulocytosis (severe loss of white cells) | 86 | 14.6 11.8–18.0ROR 14.8 · χ² 1,071 / p 3e-235 | 14.4 EB05 12.0 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 9.5 · 95% clinician | no trial data cached |
| Toxic epidermal necrolysis (severe skin peeling reaction) | 63 | 13.1 10.2–16.8ROR 13.2 · χ² 690 / p 3e-152 | 12.9 EB05 10.3 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.6 · 100% clinician | no trial data cached |
| Bacteraemia | 49 | 13.1 9.9–17.3ROR 13.1 · χ² 531 / p 7e-118 | 12.8 EB05 9.9 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 8.6 | no trial data cached |
| Cytopenia | 48 | 12.6 9.5–16.7ROR 12.7 · χ² 499 / p 8e-111 | 12.3 EB05 9.5 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.3 | no trial data cached |
| Encephalopathy | 96 | 12.3 10.1–15.0ROR 12.5 · χ² 981 / p 1e-215 | 12.1 EB05 10.2 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 · 99% clinician | no trial data cached |
| Hyperbilirubinaemia | 40 | 12.2 8.9–16.6ROR 12.2 · χ² 398 / p 9e-89 | 11.8 EB05 8.8 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 | no trial data cached |
| Cytomegalovirus infection | 59 | 11.1 8.6–14.3ROR 11.2 · χ² 532 / p 7e-118 | 10.8 EB05 8.6 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 7.4 · 92% clinician | no trial data cached |
| Febrile neutropenia | 211 | 10.0 8.7–11.4ROR 10.3 · χ² 1,696 / p <1e-300 | 9.9 EB05 8.8 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.5 | no trial data cached |
| Drug resistance | 80 | 9.8 7.8–12.1ROR 9.9 · χ² 619 / p 7e-137 | 9.5 EB05 7.8 · IC025 +2.8 3/3 methods agree | Reporting / coding artifact | serious PRR 6.7 · 94% clinician | no trial data cached |
| Cholestasis (bile flow blockage) | 59 | 9.7 7.5–12.5ROR 9.8 · χ² 449 / p 5e-100 | 9.3 EB05 7.4 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 · 100% clinician | no trial data cached |
| Pancytopenia (all blood cells low) | 171 | 9.6 8.3–11.1ROR 9.8 · χ² 1,310 / p 4e-287 | 9.5 EB05 8.3 · IC025 +3.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.3 · 94% clinician | no trial data cached |
| Acute myeloid leukaemia | 45 | 9.1 6.8–12.1ROR 9.1 · χ² 314 / p 2e-70 | 8.6 EB05 6.6 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 | no trial data cached |
| Rash maculo-papular | 64 | 9.0 7.1–11.5ROR 9.1 · χ² 449 / p 6e-100 | 8.7 EB05 7.0 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 · ♀ 64% (drug 42%) · 97% clinician | no trial data cached |
| Schizophrenia | 35 | 9.0 6.5–12.5ROR 9.1 · χ² 241 / p 1e-54 | 8.4 EB05 6.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.1 · ♀ 100% (drug 42%) · 91% clinician | no trial data cached |
| Covid-19 pneumonia | 32 | 8.4 6.0–11.9ROR 8.5 · χ² 202 / p 5e-46 | 7.8 EB05 5.7 · IC025 +2.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 5.6 · 100% clinician | no trial data cached |
| Septic shock | 114 | 8.3 6.9–9.9ROR 8.4 · χ² 720 / p 8e-159 | 8.1 EB05 6.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 · ♀ 21% (drug 42%) · 93% clinician | no trial data cached |
| Drug eruption | 46 | 8.2 6.1–10.9ROR 8.2 · χ² 282 / p 1e-63 | 7.7 EB05 6.0 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 | no trial data cached |
| Drug reaction with eosinophilia and systemic symptoms | 65 | 8.0 6.3–10.1ROR 8.0 · χ² 388 / p 1e-86 | 7.6 EB05 6.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 · 100% clinician | no trial data cached |
| Drug level increased | 41 | 7.7 5.7–10.5ROR 7.8 · χ² 234 / p 4e-53 | 7.2 EB05 5.5 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 5.6 · 100% clinician | no trial data cached |
| Oesophagitis | 27 | 7.7 5.3–11.3ROR 7.8 · χ² 151 / p 5e-35 | 7.0 EB05 5.0 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 · ♀ 0% (drug 42%) · 100% clinician | no trial data cached |
| Clostridium difficile colitis | 26 | 7.7 5.2–11.3ROR 7.7 · χ² 144 / p 2e-33 | 6.9 EB05 4.9 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 · ♀ 22% (drug 42%) | no trial data cached |
| Respiratory failure | 170 | 7.3 6.3–8.5ROR 7.5 · χ² 917 / p 8e-202 | 7.2 EB05 6.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 · 93% clinician | no trial data cached |
| Disseminated intravascular coagulation | 31 | 6.9 4.8–9.8ROR 6.9 · χ² 149 / p 1e-34 | 6.3 EB05 4.6 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 · 97% clinician | no trial data cached |
| Candida infection (yeast infection) | 36 | 6.8 4.9–9.4ROR 6.8 · χ² 170 / p 3e-39 | 6.3 EB05 4.7 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 · 92% clinician | no trial data cached |
| Multiple organ dysfunction syndrome | 60 | 6.7 5.2–8.7ROR 6.8 · χ² 287 / p 1e-64 | 6.4 EB05 5.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 · ♀ 65% (drug 42%) · 100% clinician | no trial data cached |
| Acute respiratory distress syndrome | 38 | 6.7 4.9–9.2ROR 6.8 · χ² 179 / p 4e-41 | 6.3 EB05 4.7 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 · ♀ 20% (drug 42%) | no trial data cached |
| Acute respiratory failure | 41 | 6.7 4.9–9.1ROR 6.7 · χ² 193 / p 4e-44 | 6.3 EB05 4.8 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 · 90% clinician | no trial data cached |
| Thrombocytopenia (low platelets) | 238 | 6.7 5.9–7.6ROR 6.9 · χ² 1,147 / p 9e-252 | 6.6 EB05 5.9 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.5 · 91% clinician | no trial data cached |
| Hepatotoxicity (liver damage) | 45 | 6.4 4.7–8.5ROR 6.4 · χ² 197 / p 4e-45 | 6.0 EB05 4.6 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.2 · 91% clinician | no trial data cached |
| Colitis | 73 | 6.1 4.8–7.6ROR 6.1 · χ² 304 / p 3e-68 | 5.8 EB05 4.8 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.2 · 90% clinician | no trial data cached |
| Renal tubular necrosis | 19 | 6.0 3.9–9.5ROR 6.1 · χ² 75 / p 2e-18 | 5.3 EB05 3.6 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 | no trial data cached |
| Bone marrow failure | 37 | 5.7 4.1–7.8ROR 5.7 · χ² 137 / p 6e-32 | 5.3 EB05 4.0 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 | no trial data cached |
| Lymphopenia | 25 | 5.6 3.8–8.2ROR 5.6 · χ² 89 / p 2e-21 | 5.1 EB05 3.6 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 · 100% clinician | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 237 | 5.5 4.8–6.2ROR 5.6 · χ² 866 / p 1e-190 | 5.4 EB05 4.9 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 · 96% clinician | no trial data cached |
| Hepatic function abnormal | 64 | 5.4 4.2–6.9ROR 5.4 · χ² 225 / p 3e-51 | 5.2 EB05 4.2 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 | no trial data cached |
| Anhedonia | 45 | 5.3 4.0–7.1ROR 5.3 · χ² 153 / p 2e-35 | 5.0 EB05 3.9 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 | 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) | 719 | 2.6 2.4–2.8ROR 2.8 · χ² 729 / p 6e-161 | 2.6 EB05 2.4 · IC025 +1.2 3/3 methods agree | Reporting / coding artifact | serious PRR 2.5 | no trial data cached |
| Pyrexia (fever) | 358 | 3.2 2.9–3.6ROR 3.4 · χ² 558 / p 1e-123 | 3.2 EB05 2.9 · IC025 +1.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.6 | no trial data cached |
| Diarrhoea (diarrhea) | 343 | 1.7 1.5–1.8ROR 1.7 · χ² 93 / p 2e-22 | 1.7 EB05 1.5 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.6 | no trial data cached |
| Pneumonia (lung infection) | 318 | 3.1 2.8–3.4ROR 3.2 · χ² 450 / p 4e-100 | 3.1 EB05 2.8 · IC025 +1.4 3/3 methods agree | Likely indication confounding term in indications | serious PRR 2.1 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 246 | 5.1 4.5–5.7ROR 5.2 · χ² 800 / p 3e-176 | 5.0 EB05 4.5 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.3 · 91% clinician | no trial data cached |
| Condition aggravated | 241 | 2.5 2.2–2.8ROR 2.5 · χ² 217 / p 2e-49 | 2.5 EB05 2.2 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious PRR 2.4 | no trial data cached |
| Thrombocytopenia (low platelets) | 238 | 6.7 5.9–7.6ROR 6.9 · χ² 1,147 / p 9e-252 | 6.6 EB05 5.9 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.5 · 91% clinician | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 237 | 5.5 4.8–6.2ROR 5.6 · χ² 866 / p 1e-190 | 5.4 EB05 4.9 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 · 96% clinician | no trial data cached |
| Death | 236 | 0.9 0.8–1.0ROR 0.9 · χ² 6 / p 0.008 | 0.9 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Outcome field, not a reaction | serious PRR 0.6 | no trial data cached |
| Rash | 221 | 1.6 1.4–1.8ROR 1.6 · χ² 49 / p 1e-12 | 1.6 EB05 1.4 · IC025 +0.4 | Labeled adverse reaction exact term | serious PRR 1.9 | no trial data cached |
| Febrile neutropenia | 211 | 10.0 8.7–11.4ROR 10.3 · χ² 1,696 / p <1e-300 | 9.9 EB05 8.8 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.5 | no trial data cached |
| Anaemia (low red blood cells) | 177 | 2.9 2.5–3.4ROR 3.0 · χ² 220 / p 4e-50 | 2.9 EB05 2.5 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 2.0 | no trial data cached |
| Pancytopenia (all blood cells low) | 171 | 9.6 8.3–11.1ROR 9.8 · χ² 1,310 / p 4e-287 | 9.5 EB05 8.3 · IC025 +3.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.3 · 94% clinician | no trial data cached |
| Respiratory failure | 170 | 7.3 6.3–8.5ROR 7.5 · χ² 917 / p 8e-202 | 7.2 EB05 6.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 · 93% clinician | no trial data cached |
| Sepsis (blood infection) | 165 | 4.6 4.0–5.4ROR 4.7 · χ² 467 / p 8e-104 | 4.6 EB05 4.0 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.0 | 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.
- Thrombotic microangiopathy — n=89, PRR 29.0
- Hepatic cytolysis — n=105, PRR 27.1
- Cytokine release syndrome — n=118, PRR 19.5
- Agranulocytosis — n=86, PRR 14.6
- Toxic epidermal necrolysis — n=63, PRR 13.1
- Bacteraemia — n=49, PRR 13.1
- Encephalopathy — n=96, PRR 12.3
- Hyperbilirubinaemia — n=40, PRR 12.2
- Cytomegalovirus infection — n=59, PRR 11.1
- Febrile neutropenia — n=211, PRR 10.0
✓ A hand-written Bradford Hill causality assessment exists for this drug: Minoxidil (oral) ↔ Pericardial effusion.
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 Atovaquone?
In FDA FAERS, the most frequently co-reported reaction terms for Atovaquone are pyrexia, diarrhoea, pneumonia, acute kidney injury, thrombocytopenia, neutropenia. 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 Atovaquone have an FDA boxed warning?
No. The FDA label retrieved for Atovaquone has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Atovaquone 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 16b69156-e5de-c601-e063-6394a90afeae, effective 20250915; matched on
openfda.generic_name.exact:"ATOVAQUONE") - 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, 315 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.