Comparative Pharmacology
Head-to-head clinical analysis: APOMORPHINE HYDROCHLORIDE versus WESTADONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: APOMORPHINE HYDROCHLORIDE versus WESTADONE.
APOMORPHINE HYDROCHLORIDE vs WESTADONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Non-ergoline dopamine agonist with high affinity for D2 and D3 receptors, moderate affinity for D4, D5, and adrenergic receptors; activates striatal dopamine receptors to improve motor function.
Mu-opioid receptor agonist; also acts as an NMDA receptor antagonist and inhibits serotonin and norepinephrine reuptake.
Subcutaneous injection: 0.2 mL (2 mg) test dose, then 0.2-0.6 mL (2-6 mg) as needed for acute hypomobility episodes; maximum single dose 0.6 mL (6 mg). Sublingual: 2-10 mg sublingually as needed, not more than every 2 hours, maximum 30 mg/day. Continuous subcutaneous infusion: 0.5-2.0 mg/hour via infusion pump.
Oral: 2.5-10 mg every 4-6 hours as needed for pain; maximum 40 mg per day.
None Documented
None Documented
Terminal elimination half-life is 40–60 minutes in adults with normal renal function; prolonged to 3–6 hours in end-stage renal disease.
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.
Approximately 90% of an intravenous dose is excreted in urine within 24 hours, primarily as unchanged drug and sulfate conjugates. Biliary/fecal excretion is minimal (<5%).
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