Promethazine / Dextromethorphan — Phenothiazine antihistamine + antitussive. Study the mechanism, listed uses and warnings from the US label on one sourced card.
Generic name
Promethazine / Dextromethorphan
Class
Phenothiazine antihistamine + antitussive
Mechanism
Promethazine: H1 receptor blocker with sedative and antiemetic effects. Dextromethorphan: acts centrally to raise the cough threshold.
Used for
Temporary relief of cough and upper-respiratory symptoms associated with allergy or the common cold
Label date: 20260710 · For learning, not clinical decisions. US label and brand information; always consult the current source.
Source snapshot checked: 2026-10-21. The source document and selected fields were compared. The complete card has not had an independent clinical review.
Mechanism: Brompheniramine: alkylamine H1 blocker with anticholinergic effects. Pseudoephedrine: alpha-adrenergic nasal decongestant. Dextromethorphan: raises the cough threshold.
On both cards: Common side effects — Sedation; Dizziness · Warnings — Contraindicated with MAOIs (dextromethorphan) · Interactions — MAOIs
Only on the Brompheniramine / Pseudoephedrine / Dextromethorphan card: Used for — Relief of cough and upper-respiratory symptoms, including nasal congestion, associated with allergy or the common cold · Common side effects — Dry mouth, nose and throat; Thickened bronchial secretions · Warnings — Severe hypertension or severe coronary artery disease; Not for newborns, premature infants, nursing mothers · Interactions — Alcohol and other CNS depressants; Antihypertensives (effect reduced)
Mechanism: Anesthetizes stretch receptors in the airways, lungs and pleura, damping the cough reflex at its source.
On both cards: Common side effects — Sedation; Dizziness
Only on the Benzonatate card: Used for — Symptomatic relief of cough in adults and children aged 10 years and older · Common side effects — Headache; Constipation; Nausea · Warnings — Bronchospasm / laryngospasm if capsule chewed or sucked; Fatal overdose, particularly in children; Hypersensitivity to related compounds
An item counts as shared only when both cards use the same wording. If a card does not list an item, that is not a statement that the effect never occurs.
Capsera