Chlorpheniramine and Dextromethorphan side effects: what 793 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Chlorpheniramine Maleate, Dextromethorphan Hydrochloride (Coricidin Hbp Cough And Cold)
Who reports
793 reports · 25% serious · 17 with death outcome · 64% female
Used for
temporarily relieves cough due to minor throat and bronchial irritation as may occur with a cold temporarily relieves runny nose and sneezing due to the common cold
Boxed warning
None in the current label
Causality screen of the 15 strongest signals
What the badges mean
- 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. 1 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 |
|---|---|---|---|---|---|---|
| Drug effect decreased | 74 | 35.8 28.8–44.4ROR 39.3 · χ² 2,469 / p <1e-300 | 35.4 EB05 29.1 · IC025 +4.5 3/3 methods agree | Reporting / coding artifact | 100% consumer | no trial data cached |
| Euphoric mood | 12 | 30.8 17.5–53.9ROR 31.2 · χ² 316 / p 5e-71 | 29.4 EB05 17.9 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Intentional overdose | 42 | 17.4 13.0–23.3ROR 18.3 · χ² 634 / p 4e-140 | 17.2 EB05 13.2 · IC025 +3.4 3/3 methods agree | Reporting / coding artifact | serious PRR 21.5 · ♀ 39% (drug 64%) · 71% consumer | no trial data cached |
| Drug abuse | 51 | 16.1 12.3–21.0ROR 17.1 · χ² 709 / p 2e-156 | 15.9 EB05 12.5 · IC025 +3.3 3/3 methods agree | Reporting / coding artifact | serious PRR 30.5 · ♀ 40% (drug 64%) · 76% consumer | no trial data cached |
| Choking | 8 | 10.9 5.5–21.7ROR 11.0 · χ² 62 / p 2e-15 | 8.2 EB05 4.0 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 29.1 | no trial data cached |
| Mydriasis | 5 | 10.3 4.3–24.7ROR 10.3 · χ² 33 / p 4e-9 | 6.6 EB05 2.7 · IC025 +0.9 3/3 methods agree | Not in label — unassessed | serious PRR 30.3 | no trial data cached |
| Delusion | 6 | 10.2 4.6–22.7ROR 10.3 · χ² 41 / p 7e-11 | 7.0 EB05 3.1 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 28.1 | no trial data cached |
| Drug effect incomplete | 13 | 9.3 5.4–16.0ROR 9.4 · χ² 88 / p 3e-21 | 7.7 EB05 4.6 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Overdose | 69 | 8.4 6.7–10.5ROR 9.1 · χ² 447 / p 1e-99 | 8.1 EB05 6.6 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious PRR 10.1 · ♀ 43% (drug 64%) · 88% consumer | no trial data cached |
| Serotonin syndrome | 6 | 8.3 3.7–18.4ROR 8.3 · χ² 31 / p 1e-8 | 5.6 EB05 2.7 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 19.0 | no trial data cached |
| Inappropriate schedule of drug administration | 22 | 8.0 5.3–12.1ROR 8.2 · χ² 129 / p 3e-30 | 7.1 EB05 4.9 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious PRR 2.9 · 100% consumer | no trial data cached |
| Abnormal behaviour | 11 | 7.3 4.0–13.1ROR 7.4 · χ² 54 / p 1e-13 | 5.8 EB05 3.4 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 14.6 | no trial data cached |
| Expired product administered | 7 | 5.6 2.7–11.6ROR 5.6 · χ² 22 / p 1e-6 | 4.2 EB05 2.2 · IC025 +0.8 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Dependence | 8 | 3.8 1.9–7.6ROR 3.8 · χ² 14 / p 1e-4 | 3.2 EB05 1.8 · IC025 +0.5 | Not in label — unassessed | serious PRR 4.4 | no trial data cached |
| Drug dependence | 21 | 3.4 2.2–5.2ROR 3.5 · χ² 34 / p 3e-9 | 3.2 EB05 2.2 · IC025 +1.0 3/3 methods agree | Reporting / coding artifact | serious PRR 6.4 · 95% consumer | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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 effect decreased | 74 | 35.8 28.8–44.4ROR 39.3 · χ² 2,469 / p <1e-300 | 35.4 EB05 29.1 · IC025 +4.5 3/3 methods agree | Reporting / coding artifact | 100% consumer | no trial data cached |
| Overdose | 69 | 8.4 6.7–10.5ROR 9.1 · χ² 447 / p 1e-99 | 8.1 EB05 6.6 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious PRR 10.1 · ♀ 43% (drug 64%) · 88% consumer | no trial data cached |
| Drug abuse | 51 | 16.1 12.3–21.0ROR 17.1 · χ² 709 / p 2e-156 | 15.9 EB05 12.5 · IC025 +3.3 3/3 methods agree | Reporting / coding artifact | serious PRR 30.5 · ♀ 40% (drug 64%) · 76% consumer | no trial data cached |
| Intentional overdose | 42 | 17.4 13.0–23.3ROR 18.3 · χ² 634 / p 4e-140 | 17.2 EB05 13.2 · IC025 +3.4 3/3 methods agree | Reporting / coding artifact | serious PRR 21.5 · ♀ 39% (drug 64%) · 71% consumer | no trial data cached |
| Inappropriate schedule of drug administration | 22 | 8.0 5.3–12.1ROR 8.2 · χ² 129 / p 3e-30 | 7.1 EB05 4.9 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious PRR 2.9 · 100% consumer | no trial data cached |
| Drug dependence | 21 | 3.4 2.2–5.2ROR 3.5 · χ² 34 / p 3e-9 | 3.2 EB05 2.2 · IC025 +1.0 3/3 methods agree | Reporting / coding artifact | serious PRR 6.4 · 95% consumer | no trial data cached |
| Drug effect incomplete | 13 | 9.3 5.4–16.0ROR 9.4 · χ² 88 / p 3e-21 | 7.7 EB05 4.6 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Euphoric mood | 12 | 30.8 17.5–53.9ROR 31.2 · χ² 316 / p 5e-71 | 29.4 EB05 17.9 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Abnormal behaviour | 11 | 7.3 4.0–13.1ROR 7.4 · χ² 54 / p 1e-13 | 5.8 EB05 3.4 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 14.6 | no trial data cached |
| Dependence | 8 | 3.8 1.9–7.6ROR 3.8 · χ² 14 / p 1e-4 | 3.2 EB05 1.8 · IC025 +0.5 | Not in label — unassessed | serious PRR 4.4 | no trial data cached |
| Choking | 8 | 10.9 5.5–21.7ROR 11.0 · χ² 62 / p 2e-15 | 8.2 EB05 4.0 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 29.1 | no trial data cached |
| Expired product administered | 7 | 5.6 2.7–11.6ROR 5.6 · χ² 22 / p 1e-6 | 4.2 EB05 2.2 · IC025 +0.8 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Serotonin syndrome | 6 | 8.3 3.7–18.4ROR 8.3 · χ² 31 / p 1e-8 | 5.6 EB05 2.7 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 19.0 | no trial data cached |
| Delusion | 6 | 10.2 4.6–22.7ROR 10.3 · χ² 41 / p 7e-11 | 7.0 EB05 3.1 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 28.1 | no trial data cached |
| Mydriasis | 5 | 10.3 4.3–24.7ROR 10.3 · χ² 33 / p 4e-9 | 6.6 EB05 2.7 · IC025 +0.9 3/3 methods agree | Not in label — unassessed | serious PRR 30.3 | no trial data cached |
Unlabeled candidate signals
Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.
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 Chlorpheniramine and Dextromethorphan?
In FDA FAERS, the most frequently co-reported reaction terms for Chlorpheniramine and Dextromethorphan are euphoric mood, abnormal behaviour, dependence, choking, serotonin syndrome, delusion. 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 Chlorpheniramine and Dextromethorphan have an FDA boxed warning?
No. The FDA label retrieved for Chlorpheniramine and Dextromethorphan has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Chlorpheniramine and Dextromethorphan 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 b1cd7d9f-0ab4-21ce-e053-2a95a90a8c3d, effective 20251204; matched on
openfda.generic_name.exact:"CHLORPHENIRAMINE MALEATE, DEXTROMETHORPHAN HYDROCHLORIDE") - 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, 16 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.