Comparative Pharmacology
Head-to-head clinical analysis: ALEVE PM versus VOLTAREN.
Head-to-head clinical analysis: ALEVE PM versus VOLTAREN.
ALEVE PM vs VOLTAREN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Diphenhydramine is a histamine H1 receptor antagonist that competes with histamine for binding at H1 receptor sites, reducing symptoms of allergic reactions and causing sedation. Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, decreasing synthesis of prostaglandins, which reduces pain and inflammation.
Diclofenac inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis, thereby providing anti-inflammatory, analgesic, and antipyretic effects.
1 tablet (220 mg naproxen sodium / 25 mg diphenhydramine HCl) orally at bedtime as needed. Maximum: 2 tablets in 24 hours.
Oral: 50-100 mg every 8-12 hours; maximum 150 mg/day. IM: 75 mg once daily for up to 2 days. Topical gel: apply 2-4 g to affected area 4 times daily.
None Documented
None Documented
Naproxen: 12-17 hours (mean 13.6 hours); sufficient for twice-daily dosing; prolonged in renal impairment. Diphenhydramine: 2.4-9.3 hours (mean 5.5 hours); longer in elderly, hepatic impairment.
Terminal elimination half-life is approximately 2 hours (range 1.2–2.5 hours) for diclofenac; this short half-life supports multiple daily dosing. The half-life is not significantly altered in renal impairment but may be prolonged in hepatic disease.
Naproxen: renal (95% as unchanged drug and metabolites, primarily as naproxen and 6-O-desmethyl naproxen). Diphenhydramine: renal (50-60% as unchanged drug and metabolites, primarily as diphenhydramine and nor diphenhydramine); small amounts in feces.
Approximately 65% of a dose is excreted renally as unchanged drug and glucuronide conjugates, with about 35% eliminated via biliary/fecal routes as metabolites.
Category C
Category C
NSAID/Antihistamine Combination
NSAID