Table 5.3.

Pharmacologic options for cough in adults [18, 19]

Drug	Dose	Comments
Dextromethorphan	10–20 mg by mouth every 4 hours as needed	Antitussive, not recommended for use in productive cough Structurally related to codeine CYP 2D6 metabolism (genetic polymorphisms common) Screen for drug interactions (may precipitate serotonin syndrome)
Codeine	10–20 mg by mouth every 4 hours as needed	Antitussive, not recommended for use in productive cough Not safe in pediatric population due to CYP 2D6 polymorphisms and potential for supratherapeutic levels in fast metabolizers. Deaths have occurred
Guaifenesin	200–400 mg by mouth every 4 hours as needed	Expectorant. Loosens secretions to aid in their expulsion
Diphenhydramine	25 mg by mouth every 4 hours	Any first-generation antihistamine is suitable for use in cough. Anticholinergic properties are useful for reducing secretions and postnasal drip
Pseudoephedrine	30–60 mg by mouth every 4–6 hours as needed	Decongestants can be tried for UACS

CYP 2D6 cytochrome P450 isoenzyme 2D6, UACS upper airway cough syndrome