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Drug · FAERS side-effect profile with label screen

Abacavir side effects: what 5,947 FDA adverse event reports show

Abacavir · 304 reaction terms · 16,035 drug–reaction co-reports · data 2026-09-14
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Drug class

Not stated in label

Who reports

5,947 reports · 95% serious · 750 with death outcome · 39% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Abacavir tablet, a nucleoside analogue human immunodeficiency virus (HIV-1) reverse transcriptase inhibitor, is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. Abacavir tablets USP 300 mg, in combination with other antiretroviral agents, are indicated for the treatment of human immunodeficiency virus (HIV-1) infection.

FDA label, Indications and Usage

What it is

Abacavir sulfate is a synthetic carbocyclic nucleoside analogue with inhibitory activity against HIV-1.

FDA label, Description section

Boxed warning

HYPERSENSITIVITY REACTIONS WARNING: HYPERSENSITIVITY REACTIONS See full prescribing information for complete boxed warning. Serious and sometimes fatal hypersensitivity reactions have occurred with abacavir sulfate. ( 5.1 ) Hypersensitivity to abacavir is a multi-organ clinical syndrome.

FDA 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 — boxed warning 1Labeled adverse reaction 3Labeled (related wording) 4Likely indication confounding 1Reporting / coding artifact 9Lab value / disease marker 1Not in label — unassessed 21
What the badges mean

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. 264 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show:
ReactionReportsPRR 95% CI · ROR · χ²/pEBGM EB05 · IC025Label screenSerious-only & strataTrial cross-check
Schizophrenia16548.5
41.7–56.4ROR 49.8 · χ² 7,525 / p <1e-300
47.6 EB05 41.8 · IC025 +5.1
3/3 methods agree
Not in label — unassessedserious PRR 30.0 · ♀ 96% (drug 39%) · 98% clinicianno trial data cached
Drug resistance29240.5
36.2–45.4ROR 42.6 · χ² 11,105 / p <1e-300
40.0 EB05 36.3 · IC025 +5.0
3/3 methods agree
Reporting / coding artifactserious PRR 26.8 · 91% clinicianno trial data cached
Coeliac disease10538.1
31.5–46.1ROR 38.8 · χ² 3,719 / p <1e-300
37.5 EB05 31.8 · IC025 +4.7
3/3 methods agree
Not in label — unassessedserious PRR 28.4 · ♀ 100% (drug 39%) · 94% clinicianno trial data cached
Immunodeficiency13733.1
28.0–39.1ROR 33.9 · χ² 4,195 / p <1e-300
32.7 EB05 28.3 · IC025 +4.6
3/3 methods agree
Likely indication confounding
term in indications
serious PRR 21.6 · ♀ 86% (drug 39%) · 94% clinicianno trial data cached
Bursitis10530.9
25.6–37.4ROR 31.5 · χ² 2,988 / p <1e-300
30.5 EB05 25.9 · IC025 +4.4
3/3 methods agree
Not in label — unassessedserious PRR 21.9 · ♀ 100% (drug 39%) · 94% clinicianno trial data cached
Eyelid ptosis7526.2
20.9–32.8ROR 26.5 · χ² 1,779 / p <1e-300
25.8 EB05 21.3 · IC025 +4.1
3/3 methods agree
Not in label — unassessedserious n=75 · ♀ 3% (drug 39%) · 94% clinicianno trial data cached
Hepatotoxicity (liver damage)13822.1
18.7–26.1ROR 22.6 · χ² 2,742 / p <1e-300
21.9 EB05 19.0 · IC025 +4.1
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 13.6 · ♀ 91% (drug 39%) · 97% clinicianno trial data cached
Prescribed overdose12022.0
18.4–26.3ROR 22.4 · χ² 2,371 / p <1e-300
21.8 EB05 18.7 · IC025 +4.0
3/3 methods agree
Not in label — unassessedserious PRR 22.6 · ♀ 100% (drug 39%) · 95% clinicianno trial data cached
Nephropathy toxic6119.4
15.1–24.9ROR 19.6 · χ² 1,042 / p 8e-229
19.2 EB05 15.5 · IC025 +3.6
3/3 methods agree
Not in label — unassessedserious PRR 12.0 · 93% clinicianno trial data cached
Blood bilirubin increased14318.7
15.9–22.0ROR 19.1 · χ² 2,370 / p <1e-300
18.6 EB05 16.2 · IC025 +3.9
3/3 methods agree
Lab value / disease markerserious PRR 12.8 · ♀ 81% (drug 39%) · 93% clinicianno trial data cached
Cholelithiasis17318.7
16.1–21.7ROR 19.2 · χ² 2,868 / p <1e-300
18.6 EB05 16.4 · IC025 +3.9
3/3 methods agree
Not in label — unassessedserious PRR 11.9 · ♀ 92% (drug 39%) · 98% clinicianno trial data cached
Exposure during pregnancy29917.0
15.2–19.0ROR 17.9 · χ² 4,487 / p <1e-300
16.9 EB05 15.4 · IC025 +3.9
3/3 methods agree
Reporting / coding artifactserious PRR 14.2 · ♀ 100% (drug 39%) · 95% clinicianno trial data cached
Treatment failure35215.2
13.7–16.8ROR 16.1 · χ² 4,647 / p <1e-300
15.1 EB05 13.8 · IC025 +3.7
3/3 methods agree
Reporting / coding artifactserious PRR 17.6 · ♀ 74% (drug 39%) · 97% clinicianno trial data cached
Anhedonia11315.1
12.6–18.1ROR 15.4 · χ² 1,469 / p <1e-300
15.0 EB05 12.8 · IC025 +3.5
3/3 methods agree
Not in label — unassessedserious PRR 10.0 · ♀ 16% (drug 39%) · 81% consumerno trial data cached
Psychotic disorder12615.1
12.7–18.0ROR 15.4 · χ² 1,640 / p <1e-300
15.0 EB05 12.9 · IC025 +3.5
3/3 methods agree
Not in label — unassessedserious PRR 9.9 · ♀ 90% (drug 39%) · 91% clinicianno trial data cached
Foetal exposure during pregnancy33814.7
13.3–16.3ROR 15.6 · χ² 4,309 / p <1e-300
14.6 EB05 13.4 · IC025 +3.7
3/3 methods agree
Reporting / coding artifactserious PRR 9.0no trial data cached
Rash erythematous19214.5
12.6–16.7ROR 15.0 · χ² 2,396 / p <1e-300
14.4 EB05 12.8 · IC025 +3.6
3/3 methods agree
Not in label — unassessedserious PRR 17.8 · ♀ 100% (drug 39%) · 96% clinicianno trial data cached
End stage renal disease7514.4
11.5–18.1ROR 14.6 · χ² 920 / p 3e-202
14.3 EB05 11.7 · IC025 +3.3
3/3 methods agree
Not in label — unassessedserious PRR 8.7no trial data cached
Treatment noncompliance21614.1
12.3–16.0ROR 14.6 · χ² 2,606 / p <1e-300
14.0 EB05 12.5 · IC025 +3.5
3/3 methods agree
Reporting / coding artifactserious PRR 12.4 · 97% clinicianno trial data cached
Renal tubular necrosis3813.7
10.0–18.8ROR 13.8 · χ² 432 / p 3e-96
13.3 EB05 10.0 · IC025 +3.0
3/3 methods agree
Not in label — unassessedserious PRR 8.3 · 91% clinicianno trial data cached
Economic problem5512.6
9.7–16.4ROR 12.7 · χ² 575 / p 2e-127
12.4 EB05 9.7 · IC025 +3.1
3/3 methods agree
Reporting / coding artifactserious PRR 8.2 · ♀ 13% (drug 39%)no trial data cached
Contraindicated product administered10612.4
10.3–15.0ROR 12.6 · χ² 1,100 / p 1e-241
12.3 EB05 10.4 · IC025 +3.2
3/3 methods agree
Reporting / coding artifactserious PRR 9.1 · ♀ 96% (drug 39%) · 94% clinicianno trial data cached
Hyperbilirubinaemia3512.0
8.6–16.7ROR 12.1 · χ² 341 / p 2e-76
11.5 EB05 8.5 · IC025 +2.8
3/3 methods agree
Not in label — unassessedserious PRR 7.2no trial data cached
Oral candidiasis (oral thrush)4412.0
8.9–16.1ROR 12.0 · χ² 430 / p 9e-96
11.6 EB05 8.8 · IC025 +2.9
3/3 methods agree
Not in label — unassessedserious PRR 9.9 · ♀ 12% (drug 39%)no trial data cached
Proteinuria6111.4
8.9–14.7ROR 11.5 · χ² 569 / p 4e-126
11.2 EB05 8.9 · IC025 +3.0
3/3 methods agree
Not in label — unassessedserious PRR 7.7 · 91% clinicianno trial data cached
Decreased immune responsiveness3010.9
7.6–15.5ROR 10.9 · χ² 258 / p 2e-58
10.2 EB05 7.2 · IC025 +2.6
3/3 methods agree
Not in label — unassessedserious PRR 8.2 · ♀ 100% (drug 39%) · 97% clinicianno trial data cached
Brain oedema3810.6
7.7–14.6ROR 10.7 · χ² 322 / p 3e-72
10.1 EB05 7.5 · IC025 +2.7
3/3 methods agree
Not in label — unassessedserious PRR 6.5 · 92% clinicianno trial data cached
Hyperlipidaemia3610.6
7.7–14.7ROR 10.7 · χ² 303 / p 3e-68
10.1 EB05 7.4 · IC025 +2.7
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 6.9 · ♀ 7% (drug 39%) · 93% clinicianno trial data cached
Hepatomegaly2910.4
7.2–14.9ROR 10.4 · χ² 236 / p 1e-53
9.7 EB05 6.8 · IC025 +2.5
3/3 methods agree
Labeled — boxed warning
exact term
serious PRR 6.8no trial data cached
Nephropathy269.8
6.7–14.4ROR 9.8 · χ² 196 / p 7e-45
9.0 EB05 6.2 · IC025 +2.4
3/3 methods agree
Not in label — unassessedserious PRR 5.6 · ♀ 17% (drug 39%)no trial data cached
Adrenal insufficiency329.4
6.7–13.4ROR 9.5 · χ² 233 / p 7e-53
8.8 EB05 6.4 · IC025 +2.5
3/3 methods agree
Not in label — unassessedserious PRR 5.6no trial data cached
Tuberculosis349.3
6.7–13.1ROR 9.4 · χ² 245 / p 2e-55
8.7 EB05 6.4 · IC025 +2.5
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 5.8 · 94% clinicianno trial data cached
Splenomegaly309.1
6.3–12.9ROR 9.1 · χ² 207 / p 4e-47
8.3 EB05 6.0 · IC025 +2.4
3/3 methods agree
Not in label — unassessedserious PRR 6.1 · ♀ 0% (drug 39%) · 96% clinicianno trial data cached
Osteopenia399.0
6.6–12.4ROR 9.1 · χ² 270 / p 5e-61
8.5 EB05 6.4 · IC025 +2.5
3/3 methods agree
Not in label — unassessedserious PRR 6.1no trial data cached
Drug interaction4059.0
8.2–9.9ROR 9.6 · χ² 2,895 / p <1e-300
8.9 EB05 8.2 · IC025 +3.0
3/3 methods agree
Reporting / coding artifactserious PRR 5.9 · 91% clinicianno trial data cached
Drug level increased408.5
6.3–11.6ROR 8.6 · χ² 258 / p 2e-58
8.0 EB05 6.0 · IC025 +2.4
3/3 methods agree
Reporting / coding artifactserious PRR 5.6 · ♀ 17% (drug 39%) · 95% clinicianno 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.

ReactionReportsPRR 95% CI · ROR · χ²/pEBGM EB05 · IC025Label screenSerious-only & strataTrial cross-check
Drug interaction4059.0
8.2–9.9ROR 9.6 · χ² 2,895 / p <1e-300
8.9 EB05 8.2 · IC025 +3.0
3/3 methods agree
Reporting / coding artifactserious PRR 5.9 · 91% clinicianno trial data cached
Vomiting3712.8
2.5–3.1ROR 2.9 · χ² 434 / p 1e-96
2.8 EB05 2.6 · IC025 +1.3
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 2.5 · ♀ 70% (drug 39%)no trial data cached
Treatment failure35215.2
13.7–16.8ROR 16.1 · χ² 4,647 / p <1e-300
15.1 EB05 13.8 · IC025 +3.7
3/3 methods agree
Reporting / coding artifactserious PRR 17.6 · ♀ 74% (drug 39%) · 97% clinicianno trial data cached
Rash3392.8
2.5–3.1ROR 2.9 · χ² 386 / p 3e-86
2.7 EB05 2.5 · IC025 +1.3
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 3.5 · ♀ 74% (drug 39%)no trial data cached
Foetal exposure during pregnancy33814.7
13.3–16.3ROR 15.6 · χ² 4,309 / p <1e-300
14.6 EB05 13.4 · IC025 +3.7
3/3 methods agree
Reporting / coding artifactserious PRR 9.0no trial data cached
Exposure during pregnancy29917.0
15.2–19.0ROR 17.9 · χ² 4,487 / p <1e-300
16.9 EB05 15.4 · IC025 +3.9
3/3 methods agree
Reporting / coding artifactserious PRR 14.2 · ♀ 100% (drug 39%) · 95% clinicianno trial data cached
Drug resistance29240.5
36.2–45.4ROR 42.6 · χ² 11,105 / p <1e-300
40.0 EB05 36.3 · IC025 +5.0
3/3 methods agree
Reporting / coding artifactserious PRR 26.8 · 91% clinicianno trial data cached
Pain2761.6
1.4–1.8ROR 1.6 · χ² 60 / p 4e-15
1.6 EB05 1.4 · IC025 +0.5Labeled adverse reaction
exact term
serious PRR 1.5no trial data cached
Thrombocytopenia (low platelets)2568.1
7.2–9.1ROR 8.4 · χ² 1,594 / p <1e-300
8.0 EB05 7.2 · IC025 +2.8
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 5.1 · ♀ 83% (drug 39%) · 95% clinicianno trial data cached
Pneumonia (lung infection)2352.6
2.3–2.9ROR 2.6 · χ² 226 / p 2e-51
2.6 EB05 2.3 · IC025 +1.1
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 1.6 · ♀ 79% (drug 39%) · 92% clinicianno trial data cached
Hypertension (high blood pressure)2293.8
3.4–4.3ROR 3.9 · χ² 476 / p 7e-106
3.8 EB05 3.4 · IC025 +1.7
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 2.9 · ♀ 67% (drug 39%)no trial data cached
Anaemia (low red blood cells)2294.2
3.7–4.8ROR 4.4 · χ² 567 / p 1e-125
4.2 EB05 3.8 · IC025 +1.9
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 2.8no trial data cached
Treatment noncompliance21614.1
12.3–16.0ROR 14.6 · χ² 2,606 / p <1e-300
14.0 EB05 12.5 · IC025 +3.5
3/3 methods agree
Reporting / coding artifactserious PRR 12.4 · 97% clinicianno 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.

✓ A hand-written Bradford Hill causality assessment exists for this drug: Abacavir ↔ Hypersensitivity reaction.

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 Abacavir?

In FDA FAERS, the most frequently co-reported reaction terms for Abacavir are pyrexia, vomiting, rash, pain, hepatic enzyme increased, thrombocytopenia. 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 Abacavir have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: HYPERSENSITIVITY REACTIONS WARNING: HYPERSENSITIVITY REACTIONS See full prescribing information for complete boxed warning. Serious and sometimes fatal hypersensitivity reactions have occurred with abacavir sulfate. ( 5.1 ) Hypersensitivity to abacavir is a multi-organ clinical syndrome.

Do FAERS signals prove that Abacavir 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

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.