Comparative Pharmacology
Head-to-head clinical analysis: NAPROSYN versus VOLTAREN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NAPROSYN versus VOLTAREN.
NAPROSYN vs VOLTAREN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, thereby reducing prostaglandin synthesis. This results in decreased inflammation, pain, and fever.
Diclofenac inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis, thereby providing anti-inflammatory, analgesic, and antipyretic effects.
250-500 mg orally twice daily; maximum 1500 mg/day. For extended-release: 750-1000 mg orally once daily.
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
Terminal elimination half-life is 12-17 hours. This long half-life allows twice-daily dosing, but may lead to drug accumulation in elderly or renally impaired patients.
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.
Renal excretion of conjugated metabolites accounts for approximately 95% of a dose, with 1-2% as unchanged naproxen. Fecal excretion is minimal (<5%).
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
NSAID