Comparative Pharmacology
Head-to-head clinical analysis: DEXTROMETHORPHAN POLISTIREX versus VICKS FORMULA 44.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEXTROMETHORPHAN POLISTIREX versus VICKS FORMULA 44.
DEXTROMETHORPHAN POLISTIREX vs VICKS FORMULA 44
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Dextromethorphan polistirex is an NMDA receptor antagonist and sigma-1 receptor agonist. It inhibits serotonin reuptake and acts on the brain stem cough center to elevate the threshold for coughing.
VICKS FORMULA 44 contains dextromethorphan (NMDA receptor antagonist and sigma-1 receptor agonist; suppresses cough by acting on the medullary cough center) and doxylamine (first-generation antihistamine; H1-receptor antagonist; anticholinergic and sedative effects).
30-60 mg orally every 12 hours; not to exceed 120 mg in 24 hours.
VICKS FORMULA 44 is a combination product containing dextromethorphan (cough suppressant) and doxylamine (antihistamine). The typical adult dose is 30 mg dextromethorphan/6.25 mg doxylamine (15 mL) orally every 6 hours as needed for cough and cold symptoms, not to exceed 4 doses per 24 hours.
None Documented
None Documented
Terminal half-life: 13–19 hours; clinical context: extended-release formulation due to polistirex complex; time to steady-state: ~3 days
Dextromethorphan: 3-6 hours (extensive metabolizers), up to 24 hours (poor metabolizers); doxylamine: 10-12 hours. Clinically, half-life may be prolonged in elderly, hepatic impairment, or CYP2D6 poor metabolizers.
Renal: ~45% as unchanged drug and metabolites (dextrorphan conjugates); fecal: <2%; biliary: minimal
Renal excretion of unchanged drug and metabolites (dextromethorphan and doxylamine): dextromethorphan is extensively metabolized; <10% excreted unchanged. Doxylamine: ~60% excreted renally as unchanged and metabolites.
Category C
Category C
Antitussive
Antitussive