Comparative Pharmacology
Head-to-head clinical analysis: ANEXSIA 5 325 versus ULTRACET.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ANEXSIA 5 325 versus ULTRACET.
ANEXSIA 5/325 vs ULTRACET
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydrocodone is a semi-synthetic opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. Acetaminophen is a para-aminophenol derivative with analgesic and antipyretic effects, primarily through central COX-2 inhibition and activation of descending serotonergic pathways.
ULTRACET is a combination of tramadol (a centrally acting opioid agonist) and acetaminophen (a centrally acting analgesic with antipyretic effects). Tramadol binds to mu-opioid receptors and inhibits norepinephrine and serotonin reuptake. Acetaminophen's mechanism is not fully understood but involves inhibition of cyclooxygenase (COX) enzymes in the central nervous system.
1-2 tablets orally every 4-6 hours as needed for pain; maximum 8 tablets per day.
1-2 tablets (37.5 mg tramadol/325 mg acetaminophen per tablet) orally every 4-6 hours as needed for pain, not to exceed 8 tablets per day.
None Documented
None Documented
Oxycodone: terminal half-life 3.2-4.3 hours (immediate-release); prolonged in hepatic impairment. Acetaminophen: terminal half-life 2-3 hours (therapeutic doses); prolonged in hepatic impairment or overdose.
Tramadol: 5.1 ± 0.9 hours (range 4-6 hours) for the parent drug; the active M1 metabolite has a half-life of 6.7 ± 1.7 hours. In hepatic impairment, tramadol half-life increases ~2-3 fold. Acetaminophen: 2-3 hours (range 1.25-3 hours); prolonged in overdose.
Oxycodone: renal excretion of metabolites (conjugated and unconjugated) and parent drug; ~10% excreted unchanged. Acetaminophen: renal excretion of metabolites (glucuronide and sulfate conjugates); ~2-4% excreted unchanged.
Tramadol and its metabolites are primarily excreted via the kidneys (approximately 90% of the dose), with about 30% excreted as unchanged drug and 60% as metabolites. Approximately 10% is excreted in feces. Acetaminophen is primarily conjugated in the liver and excreted renally as glucuronide (60-80%) and sulfate (20-30%) conjugates, with about 5% excreted unchanged.
Category C
Category C
Opioid Analgesic Combination
Opioid Analgesic Combination