Clopidogrel Bisulfate side effects: what 101,649 FDA adverse event reports show

Clopidogrel Bisulfate · 1,244 reaction terms · 355,194 drug–reaction co-reports · data 2026-09-14

Drug class

Not stated in label

Who reports

101,649 reports · 86% serious · 11,097 with death outcome · 42% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Clopidogrel tablets are P2Y 12 platelet inhibitor indicated for: ● Acute coronary syndrome – For patients with non–ST-segment elevation ACS (unstable angina [UA]/non–ST-elevation myocardial infarction [NSTEMI]), clopidogrel tablets have been shown to reduce the rate of myocardial infarction (MI) and stroke.

FDA label, Indications and Usage

What it is

Clopidogrel tablets, USP are a thienopyridine class inhibitor of P2Y 12 ADP platelet receptors.

FDA label, Description section

Boxed warning

DIMINISHED ANTIPLATELET EFFECT IN PATIENTS WITH TWO LOSS-OF-FUNCTION ALLELES OF THE CYP2C19 GENE See full prescribing information for complete boxed warning. Effectiveness of c lopidogrel bisulfate depends on conversion to an active metabolite by the cytochrome P450 (CYP) system, principally CYP2C19.

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 adverse reaction 2Labeled (related wording) 2Likely indication confounding 7Reporting / coding artifact 1Lab value / disease marker 1Not in label — unassessed 27

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, 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). 1,204 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show: hide coding/lab/outcome terms hide indication terms unlabeled only hide PRR-only

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Fractional exhaled nitric oxide increased	120	476.6 343.4–661.3ROR 477.1 · calibrated p 4e-13 ✓	139.7 EB05 119.9 · IC025 +6.2 3/3 methods agree	Not in label — unassessed	serious n=120 · ♀ 0% (drug 42%)	not reported in cached trials
Eosinophilic bronchitis	83	143.7 108.5–190.3ROR 143.8 · calibrated p 1e-8 ✓	82.9 EB05 69.0 · IC025 +5.5 3/3 methods agree	Not in label — unassessed	serious n=83 · ♀ 100% (drug 42%) · 100% clinician	not reported in cached trials
Coronary revascularisation	61	126.1 91.6–173.5ROR 126.1 · calibrated p 4e-8 ✓	76.3 EB05 61.5 · IC025 +5.2 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious n=61 · 100% clinician	not reported in cached trials
Vascular stent thrombosis	641	95.0 86.5–104.4ROR 95.6 · calibrated p 2e-7 ✓	64.9 EB05 60.8 · IC025 +5.8 3/3 methods agree	Not in label — unassessed	serious n=641 · 91% clinician	not reported in cached trials
Spinal epidural haematoma	136	65.4 53.9–79.4ROR 65.5 · calibrated p 3e-6 ✓	49.4 EB05 42.8 · IC025 +5.1 3/3 methods agree	Not in label — unassessed	serious n=136 · ♀ 65% (drug 42%) · 100% clinician	not reported in cached trials
Insulin autoimmune syndrome	82	64.6 50.4–82.9ROR 64.7 · calibrated p 4e-6 ✓	48.7 EB05 40.5 · IC025 +4.9 3/3 methods agree	Labeled adverse reaction exact term	serious n=82 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Vascular stent stenosis	76	45.9 35.8–58.9ROR 46.0 · calibrated p 3e-5 ✓	37.3 EB05 30.8 · IC025 +4.5 3/3 methods agree	Not in label — unassessed	serious n=76 · ♀ 100% (drug 42%) · 100% clinician	not reported in cached trials
Coronary artery restenosis	89	35.7 28.5–44.7ROR 35.7 · calibrated p 1e-4 ✓	30.3 EB05 25.4 · IC025 +4.4 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious n=88 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Respiratory tract haemorrhage	84	33.6 26.7–42.4ROR 33.7 · calibrated p 2e-4 ✓	28.8 EB05 24.0 · IC025 +4.3 3/3 methods agree	Labeled (related wording) related wording	serious n=84 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Labelled drug-drug interaction medication error	1,199	31.9 30.0–33.9ROR 32.3 · calibrated p 2e-4 ✓	27.7 EB05 26.4 · IC025 +4.7 3/3 methods agree	Reporting / coding artifact	serious PRR 22.0	not reported in cached trials
Vascular pseudoaneurysm	212	28.4 24.6–32.8ROR 28.5 · calibrated p 4e-4 ✓	25.0 EB05 22.3 · IC025 +4.3 3/3 methods agree	Not in label — unassessed	serious n=208 · 90% clinician	NCT00335452: 9/6,253 (0.1%) on Clopidogrel Bisulfate (serious AE)
Hyphaema	62	27.5 21.1–35.9ROR 27.6 · calibrated p 5e-4 ✓	24.2 EB05 19.6 · IC025 +3.9 3/3 methods agree	Not in label — unassessed	serious n=62 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Thrombosis in device	370	25.9 23.2–28.8ROR 25.9 · calibrated p 6e-4 ✓	23.0 EB05 21.1 · IC025 +4.3 3/3 methods agree	Not in label — unassessed	serious n=367 · 94% clinician	not reported in cached trials
Arterial haemorrhage	119	23.7 19.6–28.7ROR 23.8 · calibrated p 1e-3 ✓	21.3 EB05 18.3 · IC025 +4.0 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious n=119 · ♀ 100% (drug 42%) · 100% clinician	NCT00335452: 1/6,254 (0.0%) on Clopidogrel Bisulfate (serious AE)
Obstructive sleep apnoea syndrome	143	23.5 19.7–27.9ROR 23.5 · calibrated p 1e-3 ✓	21.1 EB05 18.3 · IC025 +4.0 3/3 methods agree	Not in label — unassessed	serious n=143	not reported in cached trials
Infective exacerbation of chronic obstructive airways disease	62	21.9 16.9–28.5ROR 21.9 · calibrated p 0.002 ✓	19.8 EB05 16.0 · IC025 +3.7 3/3 methods agree	Not in label — unassessed	serious n=62 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Extradural haematoma	118	20.0 16.6–24.2ROR 20.0 · calibrated p 0.002 ✓	18.3 EB05 15.6 · IC025 +3.8 3/3 methods agree	Not in label — unassessed	serious n=117 · 100% clinician	not reported in cached trials
Myoglobin blood increased	136	20.0 16.8–23.8ROR 20.0 · calibrated p 0.002 ✓	18.2 EB05 15.8 · IC025 +3.8 3/3 methods agree	Lab value / disease marker	serious n=136 · ♀ 0% (drug 42%)	not reported in cached trials
Blood loss anaemia	187	18.8 16.2–21.8ROR 18.8 · calibrated p 0.003 ✓	17.3 EB05 15.3 · IC025 +3.8 3/3 methods agree	Labeled (related wording) related wording	serious n=186 · 100% clinician	not reported in cached trials
Arterial stenosis	72	18.3 14.4–23.3ROR 18.4 · calibrated p 0.003 ✓	16.8 EB05 13.8 · IC025 +3.5 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious n=72 · 100% clinician	not reported in cached trials
Coronary artery stenosis	410	18.2 16.4–20.1ROR 18.2 · calibrated p 0.003 ✓	16.7 EB05 15.4 · IC025 +3.9 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious n=409	not reported in cached trials
Haematoma muscle	95	18.0 14.6–22.2ROR 18.0 · calibrated p 0.003 ✓	16.6 EB05 13.9 · IC025 +3.6 3/3 methods agree	Not in label — unassessed	serious n=94 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Carotid arteriosclerosis	81	17.6 14.1–22.1ROR 17.7 · calibrated p 0.004 ✓	16.2 EB05 13.5 · IC025 +3.5 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious n=81 · 100% clinician	not reported in cached trials
Acquired haemophilia	78	17.6 14.0–22.2ROR 17.6 · calibrated p 0.004 ✓	16.2 EB05 13.4 · IC025 +3.5 3/3 methods agree	Labeled adverse reaction exact term	serious n=78 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Coronary artery thrombosis	157	17.3 14.7–20.3ROR 17.3 · calibrated p 0.004 ✓	15.9 EB05 14.0 · IC025 +3.7 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious n=156	NCT00335452: 1/6,254 (0.0%) on Clopidogrel Bisulfate (serious AE)
Retroperitoneal haematoma	167	16.9 14.4–19.8ROR 16.9 · calibrated p 0.004 ✓	15.6 EB05 13.7 · IC025 +3.7 3/3 methods agree	Not in label — unassessed	serious n=166 · 100% clinician	NCT00335452: 2/6,253 (0.0%) on Clopidogrel Bisulfate (serious AE)
Hyperparathyroidism secondary	192	16.9 14.6–19.5ROR 16.9 · calibrated p 0.004 ✓	15.6 EB05 13.8 · IC025 +3.7 3/3 methods agree	Not in label — unassessed	serious n=192	not reported in cached trials
Chronic kidney disease-mineral and bone disorder	81	16.7 13.3–21.0ROR 16.7 · calibrated p 0.005 ✓	15.4 EB05 12.8 · IC025 +3.5 3/3 methods agree	Not in label — unassessed	serious n=81	not reported in cached trials
Melaena (black stool)	1,562	15.7 14.9–16.5ROR 15.9 · calibrated p 0.005 ✓	14.6 EB05 14.0 · IC025 +3.8 3/3 methods agree	Not in label — unassessed	age-adj. PRR 8.9 · serious PRR 9.9 · 92% clinician	NCT00335452: 1/6,312 (0.0%) on Clopidogrel Bisulfate (serious AE)
Nephrogenic anaemia	329	15.6 13.9–17.4ROR 15.6 · calibrated p 0.006 ✓	14.5 EB05 13.2 · IC025 +3.6 3/3 methods agree	Not in label — unassessed	serious n=329	NCT00335452: 2/6,253 (0.0%) on Clopidogrel Bisulfate (serious AE)
Systolic dysfunction	73	15.3 12.1–19.4ROR 15.3 · calibrated p 0.007 ✓	14.2 EB05 11.6 · IC025 +3.3 3/3 methods agree	Not in label — unassessed	serious n=73 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Haemorrhagic transformation stroke	103	15.1 12.4–18.5ROR 15.1 · calibrated p 0.007 ✓	14.1 EB05 11.9 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious n=102 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Oesophageal spasm	126	15.1 12.6–18.1ROR 15.1 · calibrated p 0.007 ✓	14.0 EB05 12.1 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious n=126 · ♀ 100% (drug 42%)	not reported in cached trials
Retroperitoneal haemorrhage	161	14.3 12.2–16.8ROR 14.3 · calibrated p 0.009 ✓	13.4 EB05 11.7 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious n=161 · 100% clinician	NCT00335452: 8/6,253 (0.1%) on Clopidogrel Bisulfate (serious AE)
Peripheral artery occlusion	90	14.1 11.4–17.5ROR 14.1 · calibrated p 0.010 ✓	13.2 EB05 11.0 · IC025 +3.3 3/3 methods agree	Not in label — unassessed	serious n=88	not reported in cached trials
Unmasking of previously unidentified disease	69	14.1 11.0–18.0ROR 14.1 · calibrated p 0.010 ✓	13.1 EB05 10.6 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious n=69 · 100% clinician	not reported in cached trials
Abdominal wall haematoma	125	14.1 11.8–16.9ROR 14.1 · calibrated p 0.009 ✓	13.2 EB05 11.3 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious n=125 · 100% clinician	not reported in cached trials
Mallory-weiss syndrome	81	14.0 11.2–17.5ROR 14.0 · calibrated p 0.010 ✓	13.0 EB05 10.8 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious n=81 · ♀ 0% (drug 42%) · 100% clinician	not reported in cached trials
Pericardial haemorrhage	139	13.9 11.7–16.5ROR 13.9 · calibrated p 0.010 ✓	13.0 EB05 11.3 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious n=139 · 100% clinician	NCT00335452: 11/6,253 (0.2%) on Clopidogrel Bisulfate (serious AE)
Subdural haemorrhage	174	13.8 11.9–16.1ROR 13.9 · calibrated p 0.010 ✓	13.0 EB05 11.4 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious n=174 · 90% clinician	NCT00335452: 1/6,312 (0.0%) on Clopidogrel Bisulfate (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
Gi bleeding	6,407	7.57.3–7.6	signal
Myocardial infarction	5,080	5.25.1–5.4	signal
Rhabdomyolysis / myopathy	1,520	3.93.7–4.1	signal
Stroke	4,656	3.93.8–4.0	signal
Anaemia	5,440	3.83.7–3.9	signal
Hyponatraemia	1,189	3.12.9–3.3	signal
Kidney injury	6,341	2.92.8–3.0	signal
Heart failure	2,481	2.92.8–3.0	signal
Arrhythmia / qt	2,608	2.82.7–2.9	signal
Fall / fracture	3,778	2.12.0–2.1	raised
Hypoglycaemia	949	2.11.9–2.2	raised
Thrombocytopenia	1,629	1.51.5–1.6	raised
Tendon disorder	274	1.51.3–1.7	raised
Serious infection	5,062	1.41.3–1.4	raised
Interstitial lung disease	628	1.41.3–1.5	raised
Liver injury	1,923	1.31.3–1.4	raised

Trial evidence (ClinicalTrials.gov)

✓ Trial adverse-event data found on ClinicalTrials.gov

Largest completed trials with posted results that list Clopidogrel Bisulfate 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 (9 of 40 signal terms matched).

NCT00335452 — Clopidogrel Optimal Loading Dose Usage to Reduce Recurrent EveNTs/Optimal Antiplatelet Strategy for Interventi (N=25086, PHASE3; 408 AE terms posted; arms: Clopidogrel 300/75/75 mg + ASA Low Dose; Clopidogrel 300/75/75 mg + ASA High Dose; Clopidogrel 600/150/75 mg + ASA Low Dose; Clopidogrel 600/150/75 mg + ASA High Dos)

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
Dyspnoea (shortness of breath)	5,392	2.0 1.9–2.0ROR 2.0 · calibrated p 0.961	2.0 EB05 1.9 · IC025 +0.9	Not in label — unassessed	age-adj. PRR 1.6 · serious PRR 1.6	NCT00335452: 2/6,312 (0.0%) on Clopidogrel Bisulfate (serious AE)
Fatigue (tiredness)	4,761	1.3 1.2–1.3ROR 1.3 · calibrated p 0.493	1.3 EB05 1.2 · IC025 +0.3	Not in label — unassessed	age-adj. PRR 1.1 · serious PRR 1.3	NCT00335452: 1/6,312 (0.0%) on Clopidogrel Bisulfate (serious AE)
Dizziness	4,169	1.7 1.7–1.8ROR 1.8 · calibrated p 0.809	1.7 EB05 1.7 · IC025 +0.7	Not in label — unassessed	age-adj. PRR 1.5 · serious PRR 1.7	NCT00335452: 1/6,267 (0.0%) on Clopidogrel Bisulfate (serious AE)
Diarrhoea (diarrhea)	4,074	1.3 1.3–1.3ROR 1.3 · calibrated p 0.522	1.3 EB05 1.3 · IC025 +0.3	Labeled adverse reaction exact term	age-adj. PRR 1.0 · serious PRR 1.2	NCT00335452: 1/6,253 (0.0%) on Clopidogrel Bisulfate (serious AE)
Drug ineffective (drug did not work)	4,035	0.6 0.6–0.7ROR 0.6 · calibrated p 0.091	0.6 EB05 0.6 · IC025 -0.7 PRR-only: not supported by EBGM or IC	Reporting / coding artifact	age-adj. PRR 0.8 · serious PRR 0.9	not reported in cached trials
Nausea	3,902	1.0 1.0–1.1ROR 1.0 · calibrated p 0.320	1.0 EB05 1.0 · IC025 -0.0 PRR-only: not supported by EBGM or IC	Not in label — unassessed	age-adj. PRR 1.0 · serious PRR 1.1	NCT00335452: 1/6,267 (0.0%) on Clopidogrel Bisulfate (serious AE)
Anaemia (low red blood cells)	3,730	4.1 4.0–4.2ROR 4.2 · calibrated p 0.341	4.0 EB05 3.9 · IC025 +2.0 3/3 methods agree	Labeled adverse reaction exact term	age-adj. PRR 3.1 · serious PRR 2.9	NCT00335452: 2/6,312 (0.0%) on Clopidogrel Bisulfate (serious AE)
Drug interaction	3,665	4.9 4.7–5.0ROR 5.0 · calibrated p 0.235	4.8 EB05 4.6 · IC025 +2.2 3/3 methods agree	Reporting / coding artifact	age-adj. PRR 3.7 · serious PRR 3.5	not reported in cached trials
Fall	3,608	2.3 2.2–2.3ROR 2.3 · calibrated p 0.904	2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree	Not in label — unassessed	age-adj. PRR 1.5 · serious PRR 1.7	NCT00335452: 1/6,253 (0.0%) on Clopidogrel Bisulfate (serious AE)
Myocardial infarction (heart attack)	3,481	4.1 4.0–4.3ROR 4.3 · calibrated p 0.333	4.1 EB05 4.0 · IC025 +2.0 3/3 methods agree	Likely indication confounding term in indications	age-adj. PRR 3.3 · serious PRR 2.7	NCT00335452: 1/6,254 (0.0%) on Clopidogrel Bisulfate (serious AE)
Off label use (used outside approved label)	3,305	0.8 0.8–0.8ROR 0.8 · calibrated p 0.171	0.8 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC	Reporting / coding artifact	age-adj. PRR 0.7 · serious PRR 0.8	not reported in cached trials
Asthenia (weakness)	3,241	1.8 1.7–1.8ROR 1.8 · calibrated p 0.836	1.8 EB05 1.7 · IC025 +0.8	Not in label — unassessed	age-adj. PRR 1.3 · serious PRR 1.5	not reported in cached trials
Acute kidney injury (sudden kidney damage)	3,160	4.3 4.2–4.5ROR 4.5 · calibrated p 0.302	4.3 EB05 4.2 · IC025 +2.0 3/3 methods agree	Not in label — unassessed	age-adj. PRR 2.6 · serious PRR 2.9	not reported in cached trials
Death	2,971	0.7 0.7–0.7ROR 0.7 · calibrated p 0.131	0.7 EB05 0.7 · IC025 -0.6 PRR-only: not supported by EBGM or IC	Outcome field, not a reaction	age-adj. PRR 0.5 · serious PRR 0.5	not reported in cached trials
Headache	2,819	0.9 0.9–1.0ROR 0.9 · calibrated p 0.259	0.9 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC	Labeled adverse reaction exact term	age-adj. PRR 1.0 · serious PRR 1.0	NCT00335452: 1/6,254 (0.0%) on Clopidogrel Bisulfate (serious AE)

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.

Fractional exhaled nitric oxide increased — n=120, PRR 476.6
Eosinophilic bronchitis — n=83, PRR 143.7
Vascular stent thrombosis — n=641, PRR 95.0
Spinal epidural haematoma — n=136, PRR 65.4
Vascular stent stenosis — n=76, PRR 45.9
Vascular pseudoaneurysm — n=212, PRR 28.4 (also seen in trial arm)
Hyphaema — n=62, PRR 27.5
Thrombosis in device — n=370, PRR 25.9
Obstructive sleep apnoea syndrome — n=143, PRR 23.5
Infective exacerbation of chronic obstructive airways disease — n=62, PRR 21.9

✓ A hand-written Bradford Hill causality assessment exists for this drug: Clopidogrel ↔ Gastrointestinal haemorrhage.

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 Clopidogrel Bisulfate?

In FDA FAERS, the most frequently co-reported reaction terms for Clopidogrel Bisulfate are dyspnoea, fatigue, dizziness, diarrhoea, nausea, anaemia. 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 Clopidogrel Bisulfate have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: DIMINISHED ANTIPLATELET EFFECT IN PATIENTS WITH TWO LOSS-OF-FUNCTION ALLELES OF THE CYP2C19 GENE See full prescribing information for complete boxed warning. Effectiveness of c lopidogrel bisulfate depends on conversion to an active metabolite by the cytochrome P450 (CYP) system, principally CYP2C19.

Do FAERS signals prove that Clopidogrel Bisulfate 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 03bec9ad-cd22-44d3-9b82-2796157de1d1, effective 20250227; matched on openfda.generic_name.exact:"CLOPIDOGREL BISULFATE" AND openfda.product_type:"HUMAN PRESCRIPTION DRUG")
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, field patient.drug.openfda.generic_name.exact, 1,244 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 CLOPIDOGREL BISULFATE, 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.