Comparative Pharmacology
Head-to-head clinical analysis: ACETAMINOPHEN AND IBUPROFEN versus VOLTAREN XR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ACETAMINOPHEN AND IBUPROFEN versus VOLTAREN XR.
ACETAMINOPHEN AND IBUPROFEN vs VOLTAREN-XR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Acetaminophen is a centrally acting analgesic and antipyretic whose exact mechanism is not fully understood, but is thought to involve inhibition of cyclooxygenase (COX) in the brain and modulation of cannabinoid receptors. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that non-selectively inhibits COX-1 and COX-2, reducing prostaglandin synthesis.
Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis. This leads to anti-inflammatory, analgesic, and antipyretic effects.
Oral: Acetaminophen 325 mg and ibuprofen 200 mg, 1-2 tablets every 6 hours as needed, not exceeding 6 tablets/24 hours.
100 mg orally once daily, extended-release formulation. Maximum 150 mg/day (divided as 75 mg twice daily or 100 mg once daily).
None Documented
None Documented
Acetaminophen: 2-3 hours (normal hepatic function). Ibuprofen: 2-4 hours (immediate-release); prolonged in overdose or hepatic impairment.
The terminal elimination half-life is approximately 2 hours. The extended-release formulation (XR) does not alter the half-life; it maintains prolonged therapeutic plasma concentrations with twice-daily dosing.
Acetaminophen: renal excretion of metabolites (glucuronide 55%, sulfate 30%, cysteine/mercapturate <10%); <5% unchanged. Ibuprofen: renal excretion of metabolites (conjugates) 90%; <10% unchanged; minor biliary/fecal.
Approximately 65% of a dose is excreted renally as unchanged drug and metabolites (primarily as glucuronide conjugates); about 35% is eliminated via bile in feces.
Category D/X
Category C
NSAID
NSAID