Comparative Pharmacology
Head-to-head clinical analysis: METHADONE HYDROCHLORIDE versus WESTADONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: METHADONE HYDROCHLORIDE versus WESTADONE.
METHADONE HYDROCHLORIDE vs WESTADONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Mu-opioid receptor agonist; also NMDA receptor antagonist and serotonin/norepinephrine reuptake inhibitor.
Mu-opioid receptor agonist; also acts as an NMDA receptor antagonist and inhibits serotonin and norepinephrine reuptake.
Oral: 20-30 mg daily for induction, then 20-120 mg daily for maintenance; IV: 2.5-10 mg every 8-12 hours for acute pain, titrated; IM/SC: same as IV. Frequency: daily for maintenance, every 8-12 hours for pain.
Oral: 2.5-10 mg every 4-6 hours as needed for pain; maximum 40 mg per day.
None Documented
None Documented
Terminal half-life 24-36 hours (range 13-50 hours) for active l-isomer; clinical context: once-daily dosing possible but cautious due to prolonged QT interval risk.
Terminal elimination half-life: 15-60 hours (mean ~24 hours). Clinical context: Prolonged half-life supports once-daily dosing in opioid maintenance; accumulation occurs with repeated dosing due to long half-life.
Renal (80-90% as methadone and metabolites; ~30% unchanged), biliary/fecal (minor ~10%)
Primarily renal (40-50% as unchanged methadone and its metabolites, 15-20% as metadone-N-oxide), biliary/fecal (5-10%).
Category D/X
Category C
Opioid Agonist
Opioid Agonist