Comparative Pharmacology
Head-to-head clinical analysis: OXYCODONE AND ASPIRIN HALF STRENGTH versus WESTADONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: OXYCODONE AND ASPIRIN HALF STRENGTH versus WESTADONE.
OXYCODONE AND ASPIRIN (HALF-STRENGTH) vs WESTADONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Oxycodone is a full opioid agonist with relative selectivity for the mu-opioid receptor, resulting in analgesia through supraspinal and spinal pathways. Aspirin irreversibly acetylates cyclooxygenase-1 and -2 (COX-1/2), inhibiting prostaglandin synthesis and providing anti-inflammatory and analgesic effects.
Mu-opioid receptor agonist; also acts as an NMDA receptor antagonist and inhibits serotonin and norepinephrine reuptake.
Adults: One to two tablets (325 mg aspirin/2.5 mg oxycodone per tablet) orally every 6 hours as needed for pain. Maximum dose: 12 tablets per day.
Oral: 2.5-10 mg every 4-6 hours as needed for pain; maximum 40 mg per day.
None Documented
None Documented
Aspirin: 2-3 hours for low doses, 15-30 hours for anti-inflammatory doses; increased half-life with dose due to saturable metabolism. Oxycodone: Immediate release: 3-4 hours; controlled release: 4.5-5 hours with biphasic absorption.
Terminal elimination half-life: 15-60 hours (mean ~24 hours). Clinical context: Prolonged half-life supports once-daily dosing in opioid maintenance; accumulation occurs with repeated dosing due to long half-life.
Aspirin: Renal (primarily as salicyluric acid, salicyl glucuronides, and free salicylate); 10% excreted as unchanged salicylate. Oxycodone: Renal (primarily as noroxycodone, oxymorphone, and conjugates); approximately 87% eliminated in urine, 10-14% in feces.
Primarily renal (40-50% as unchanged methadone and its metabolites, 15-20% as metadone-N-oxide), biliary/fecal (5-10%).
Category D/X
Category C
Opioid Agonist
Opioid Agonist