Dexchlorpheniramine side effects: what 990 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Dexchlorpheniramine Maleate (Ryclora)
Who reports
990 reports · 97% serious · 144 with death outcome · 53% female
Used for
Perennial and seasonal allergic rhinitis Vasomotor rhinitis Allergic conjunctivitis due to inhalant allergens and foods Mild, uncomplicated allergic skin manifestations of urticaria and angioedema Amelioration of allergic reactions to blood or plasma Dermographism As therapy for anaphylactic reactions adjunctive to epinephrine and other standard measures after the acute manifestations have been controlled.
What it is
DESCRIPTION Each 5 mL (teaspoonful) contains: Dexchlorpheniramine Maleate, USP 2 mg Dexchlorpheniramine Maleate, USP, an antihistamine agent, is a white, odorless crystalline powder that is freely soluble in water.
Boxed warning
None in the current label
Causality screen of the 28 strongest signals
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.
- 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. 4 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 |
|---|---|---|---|---|---|---|
| Cytokine release syndrome | 39 | 43.4 31.9–59.1ROR 45.2 · χ² 1,573 / p <1e-300 | 42.5 EB05 32.5 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 26.0 · 92% clinician | no trial data cached |
| Hepatocellular injury | 20 | 29.8 19.3–46.1ROR 30.4 · χ² 528 / p 3e-117 | 29.1 EB05 19.9 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 17.7 · 100% clinician | no trial data cached |
| Cytomegalovirus infection | 17 | 21.7 13.5–34.7ROR 22.0 · χ² 315 / p 1e-70 | 21.1 EB05 13.8 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 12.3 | no trial data cached |
| Anaphylactic shock | 25 | 20.7 14.0–30.5ROR 21.2 · χ² 449 / p 6e-100 | 20.3 EB05 14.4 · IC025 +3.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 12.3 · 96% clinician | no trial data cached |
| Infusion related reaction (reaction during infusion) | 64 | 20.5 16.2–26.0ROR 21.9 · χ² 1,173 / p 2e-257 | 20.4 EB05 16.5 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious PRR 15.4 · 100% clinician | no trial data cached |
| Febrile neutropenia | 64 | 20.5 16.2–26.0ROR 21.8 · χ² 1,170 / p 1e-256 | 20.4 EB05 16.5 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious PRR 12.0 · 98% clinician | no trial data cached |
| Hepatic cytolysis | 11 | 19.1 10.6–34.4ROR 19.3 · χ² 171 / p 3e-39 | 18.0 EB05 9.9 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 11.3 | no trial data cached |
| Retinal detachment | 8 | 18.4 9.2–36.8ROR 18.6 · χ² 115 / p 4e-27 | 16.5 EB05 7.4 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 11.1 | no trial data cached |
| Neutrophil count decreased | 31 | 16.2 11.5–22.9ROR 16.7 · χ² 428 / p 2e-95 | 16.0 EB05 11.6 · IC025 +3.1 3/3 methods agree | Lab value / disease marker | serious PRR 10.8 · 97% clinician | no trial data cached |
| Bronchospasm (airway tightening) | 10 | 14.8 8.0–27.4ROR 14.9 · χ² 115 / p 3e-27 | 13.1 EB05 6.5 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 9.7 | no trial data cached |
| Erythema multiforme | 6 | 13.6 6.1–30.3ROR 13.7 · χ² 58 / p 1e-14 | 10.0 EB05 4.0 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.4 | no trial data cached |
| Oesophagitis | 7 | 13.6 6.5–28.4ROR 13.7 · χ² 69 / p 4e-17 | 10.5 EB05 4.5 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 8.9 | no trial data cached |
| Lymphopenia | 9 | 13.6 7.1–26.0ROR 13.7 · χ² 92 / p 3e-22 | 11.4 EB05 5.4 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 8.7 | no trial data cached |
| Metastases to lung | 6 | 11.0 5.0–24.5ROR 11.1 · χ² 45 / p 9e-12 | 7.6 EB05 3.3 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 | no trial data cached |
| Thrombotic microangiopathy | 5 | 10.9 4.6–26.2ROR 11.0 · χ² 36 / p 1e-9 | 7.0 EB05 2.8 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.5 | no trial data cached |
| Akathisia (inner restlessness) | 7 | 10.9 5.2–22.7ROR 10.9 · χ² 53 / p 1e-13 | 7.9 EB05 3.6 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 9.2 | no trial data cached |
| Rash maculo-papular | 11 | 10.5 5.8–18.9ROR 10.6 · χ² 86 / p 1e-20 | 8.6 EB05 4.7 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 | no trial data cached |
| Hypothermia | 5 | 10.4 4.4–25.0ROR 10.5 · χ² 34 / p 3e-9 | 6.7 EB05 2.8 · IC025 +0.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
| Agranulocytosis (severe loss of white cells) | 9 | 10.3 5.4–19.8ROR 10.4 · χ² 67 / p 2e-16 | 8.0 EB05 4.1 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.1 | no trial data cached |
| Pharyngitis | 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 7.8 | no trial data cached |
| Mucosal inflammation | 12 | 9.8 5.6–17.1ROR 9.9 · χ² 86 / p 1e-20 | 8.0 EB05 4.6 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Shock | 10 | 9.3 5.0–17.2ROR 9.4 · χ² 66 / p 2e-16 | 7.3 EB05 4.0 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.0 | no trial data cached |
| Face oedema | 7 | 8.8 4.2–18.3ROR 8.8 · χ² 41 / p 9e-11 | 6.2 EB05 3.1 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 | no trial data cached |
| Multi-organ failure | 7 | 8.5 4.0–17.7ROR 8.5 · χ² 39 / p 2e-10 | 6.0 EB05 3.0 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.0 | no trial data cached |
| Interstitial lung disease | 16 | 7.0 4.3–11.4ROR 7.1 · χ² 77 / p 1e-18 | 6.0 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.2 | no trial data cached |
| Myelosuppression | 9 | 5.6 2.9–10.7ROR 5.6 · χ² 30 / p 3e-8 | 4.5 EB05 2.5 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 3.3 | no trial data cached |
| Peritonitis | 5 | 5.1 2.1–12.3ROR 5.1 · χ² 13 / p 2e-4 | 3.7 EB05 1.8 · IC025 +0.3 | Not in label — unassessed | serious PRR 3.0 | no trial data cached |
| Palmar-plantar erythrodysaesthesia syndrome | 5 | 4.5 1.9–10.9ROR 4.5 · χ² 10 / p 6e-4 | 3.4 EB05 1.6 · IC025 +0.2 | Not in label — unassessed | serious PRR 3.6 | 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 |
|---|---|---|---|---|---|---|
| Febrile neutropenia | 64 | 20.5 16.2–26.0ROR 21.8 · χ² 1,170 / p 1e-256 | 20.4 EB05 16.5 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious PRR 12.0 · 98% clinician | no trial data cached |
| Infusion related reaction (reaction during infusion) | 64 | 20.5 16.2–26.0ROR 21.9 · χ² 1,173 / p 2e-257 | 20.4 EB05 16.5 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious PRR 15.4 · 100% clinician | no trial data cached |
| Cytokine release syndrome | 39 | 43.4 31.9–59.1ROR 45.2 · χ² 1,573 / p <1e-300 | 42.5 EB05 32.5 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 26.0 · 92% clinician | no trial data cached |
| Neutrophil count decreased | 31 | 16.2 11.5–22.9ROR 16.7 · χ² 428 / p 2e-95 | 16.0 EB05 11.6 · IC025 +3.1 3/3 methods agree | Lab value / disease marker | serious PRR 10.8 · 97% clinician | no trial data cached |
| Anaphylactic shock | 25 | 20.7 14.0–30.5ROR 21.2 · χ² 449 / p 6e-100 | 20.3 EB05 14.4 · IC025 +3.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 12.3 · 96% clinician | no trial data cached |
| Hepatocellular injury | 20 | 29.8 19.3–46.1ROR 30.4 · χ² 528 / p 3e-117 | 29.1 EB05 19.9 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 17.7 · 100% clinician | no trial data cached |
| Cytomegalovirus infection | 17 | 21.7 13.5–34.7ROR 22.0 · χ² 315 / p 1e-70 | 21.1 EB05 13.8 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 12.3 | no trial data cached |
| Interstitial lung disease | 16 | 7.0 4.3–11.4ROR 7.1 · χ² 77 / p 1e-18 | 6.0 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.2 | no trial data cached |
| Mucosal inflammation | 12 | 9.8 5.6–17.1ROR 9.9 · χ² 86 / p 1e-20 | 8.0 EB05 4.6 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Rash maculo-papular | 11 | 10.5 5.8–18.9ROR 10.6 · χ² 86 / p 1e-20 | 8.6 EB05 4.7 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 | no trial data cached |
| Hepatic cytolysis | 11 | 19.1 10.6–34.4ROR 19.3 · χ² 171 / p 3e-39 | 18.0 EB05 9.9 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 11.3 | no trial data cached |
| Shock | 10 | 9.3 5.0–17.2ROR 9.4 · χ² 66 / p 2e-16 | 7.3 EB05 4.0 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.0 | no trial data cached |
| Bronchospasm (airway tightening) | 10 | 14.8 8.0–27.4ROR 14.9 · χ² 115 / p 3e-27 | 13.1 EB05 6.5 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 9.7 | no trial data cached |
| Myelosuppression | 9 | 5.6 2.9–10.7ROR 5.6 · χ² 30 / p 3e-8 | 4.5 EB05 2.5 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 3.3 | no trial data cached |
| Agranulocytosis (severe loss of white cells) | 9 | 10.3 5.4–19.8ROR 10.4 · χ² 67 / p 2e-16 | 8.0 EB05 4.1 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.1 | 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.
- Cytokine release syndrome — n=39, PRR 43.4
- Hepatocellular injury — n=20, PRR 29.8
- Infusion related reaction — n=64, PRR 20.5
- Febrile neutropenia — n=64, PRR 20.5
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 Dexchlorpheniramine?
In FDA FAERS, the most frequently co-reported reaction terms for Dexchlorpheniramine are febrile neutropenia, infusion related reaction, cytokine release syndrome, neutrophil count decreased, anaphylactic shock, hepatocellular injury. 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 Dexchlorpheniramine have an FDA boxed warning?
No. The FDA label retrieved for Dexchlorpheniramine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Dexchlorpheniramine 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 aa4f80c9-e600-4bc0-8528-02a8162a36f0, effective 20240108; matched on
openfda.generic_name.exact:"DEXCHLORPHENIRAMINE MALEATE") - 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, 32 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.