Comparative Pharmacology
Head-to-head clinical analysis: DURAGESIC 25 versus TALWIN 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DURAGESIC 25 versus TALWIN 50.
DURAGESIC-25 vs TALWIN 50
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Fentanyl is a mu-opioid receptor agonist that produces analgesia and sedation by mimicking endogenous opioids in the central nervous system.
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.
Apply 25 mcg/hour transdermally every 72 hours; initial dose in opioid-naive patients: 25 mcg/hour is not recommended; use lower strength or immediate-release opioid first.
50 mg orally every 3-4 hours as needed; maximum 600 mg per day.
None Documented
None Documented
Terminal elimination half-life 22-25 hours (range 13-31 h) after 72-h transdermal application; prolonged in elderly, hepatic or renal impairment
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 (75% as metabolites, <10% unchanged); fecal (9%)
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