Comparative Pharmacology
Head-to-head clinical analysis: DURAGESIC 25 versus MEPERGAN.
Head-to-head clinical analysis: DURAGESIC 25 versus MEPERGAN.
DURAGESIC-25 vs MEPERGAN
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.
Meperidine is a synthetic opioid agonist that binds to mu-opioid receptors in the central nervous system, mimicking endogenous endorphins to produce analgesia. Promethazine is a phenothiazine antipsychotic that antagonizes histamine H1, dopamine D2, muscarinic acetylcholine, and alpha-adrenergic receptors, providing sedation and antiemetic effects.
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.
Meperidine 50-100 mg and promethazine 25-50 mg IM/IV every 3-4 hours as needed. Maximum meperidine dose: 600 mg/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
Meperidine: 3-4 hours (terminal; increased in hepatic impairment). Promethazine: 9-16 hours (terminal; prolonged in elderly).
Renal (75% as metabolites, <10% unchanged); fecal (9%)
Renal elimination of metabolites (meperidine: ~90% as metabolites, <5% unchanged; promethazine: ~70-80% as metabolites, <1% unchanged). Biliary/fecal excretion is minimal (<10% for both).
Category C
Category C
Opioid Analgesic
Opioid Analgesic/Antiemetic Combination