Comparative Pharmacology
Head-to-head clinical analysis: DARVON N W ASA versus DOLENE AP 65.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON N W ASA versus DOLENE AP 65.
DARVON-N W/ ASA vs DOLENE AP-65
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Propoxyphene is a weak opioid agonist that binds to mu-opioid receptors in the CNS, altering pain perception. Aspirin inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis, which mediates pain, fever, and inflammation.
DOLENE AP-65 is a combination of dipyrone (metamizole) and propantheline. Dipyrone is a non-opioid analgesic and antipyretic that acts centrally and peripherally via inhibition of cyclooxygenase and activation of the endocannabinoid system. Propantheline is an anticholinergic agent that inhibits muscarinic acetylcholine receptors, reducing gastrointestinal motility and spasm.
1-2 capsules (propoxyphene napsylate 100 mg / aspirin 325 mg per capsule) orally every 4 hours as needed for pain; maximum 6 capsules per day.
DOLENE AP-65 (propoxyphene napsylate 100 mg and acetaminophen 650 mg). Adult: 1 tablet orally every 4 hours as needed for pain. Maximum: 6 tablets per day.
None Documented
None Documented
Propoxyphene: terminal elimination half-life is 6-12 hours in adults with normal renal function; norpropoxyphene has a longer half-life (30-36 hours). Aspirin (as salicylate): half-life is dose-dependent, ranging from 2-3 hours at low doses to 15-30 hours at anti-inflammatory doses (300-600 mg in Darvon-N W/ASA).
2-3 hours in adults with normal hepatic function; prolonged in hepatic impairment (up to 5-10 hours) and in neonates (up to 3-5 hours)
Renal: propoxyphene and its metabolites (norpropoxyphene) are primarily eliminated via kidneys, with ~20-25% excreted unchanged; fecal: minor; biliary: some enterohepatic recirculation occurs, but exact % are not well quantified for the combination product. Aspirin is hydrolyzed to salicylate, which is excreted renally (75% as salicyluric acid, 10% as salicylic acid, 10% as glucuronide conjugates, and minor amounts as gentisic acid).
Renal: 90% (50% as acetaminophen glucuronide, 30% as sulfate, 5% as cysteine, 3% as unchanged drug, 2% as other metabolites); Fecal: <5%
Category C
Category C
Opioid Analgesic Combination
Opioid Analgesic Combination