Comparative Pharmacology
Head-to-head clinical analysis: DEMEROL versus TALWIN 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEMEROL versus TALWIN 50.
DEMEROL vs TALWIN 50
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Meperidine is an opioid agonist that binds to mu-opioid receptors in the central nervous system, mimicking endogenous endorphins to produce analgesia, sedation, and euphoria. It also has additional weak actions at kappa and delta receptors.
Pentazocine is a mixed agonist-antagonist opioid analgesic with activity at kappa opioid receptors (agonist) and mu opioid receptors (partial agonist/antagonist). It also exhibits weak antagonistic activity at mu receptors, which reduces abuse liability but may precipitate withdrawal in opioid-dependent patients.
50-150 mg IM, IV, or SC every 3-4 hours as needed for pain; oral 50-150 mg every 3-4 hours.
50 mg orally every 3-4 hours as needed; maximum 600 mg per day.
None Documented
None Documented
2.5-4 hours; prolonged in hepatic impairment (7-11 hours) and elderly.
Terminal elimination half-life is 2-3 hours. In patients with hepatic impairment, half-life may extend to 5-8 hours; in renal impairment, minimal change, but active metabolite accumulation may occur.
Renal (90% as metabolites and unchanged drug; ~5% unchanged) and biliary/fecal (minor).
Primarily renal (60-70% as unchanged drug and conjugates), with 20-30% biliary/fecal elimination. Approximately 5-10% excreted in feces via bile.
Category C
Category C
Opioid Analgesic
Opioid Analgesic