Comparative Pharmacology
Head-to-head clinical analysis: LEVORPHANOL TARTRATE versus MEPERGAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVORPHANOL TARTRATE versus MEPERGAN.
LEVORPHANOL TARTRATE vs MEPERGAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Levorphanol is a potent opioid analgesic that acts as a mu-opioid receptor agonist. It also has NMDA receptor antagonist activity, inhibits norepinephrine and serotonin reuptake, and acts as a sigma receptor agonist, contributing to its analgesic effects and reduced tolerance development.
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.
2 mg orally every 6-8 hours as needed for pain; for opioid-tolerant patients, doses up to 4 mg orally every 6-8 hours may be used. Parenterally: 1-2 mg subcutaneously or intramuscularly every 6-8 hours; may be given intravenously at 0.5-1 mg every 6-8 hours.
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
11-16 hours; extended in hepatic impairment (up to 30 hours).
Meperidine: 3-4 hours (terminal; increased in hepatic impairment). Promethazine: 9-16 hours (terminal; prolonged in elderly).
Renal: approximately 30% as unchanged drug and 50% as glucuronide conjugates; fecal: 20% via biliary excretion.
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