Comparative Pharmacology
Head-to-head clinical analysis: NUMORPHAN versus SUBSYS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NUMORPHAN versus SUBSYS.
NUMORPHAN vs SUBSYS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Opioid agonist; binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception.
SUBSYS (fentanyl) is a mu-opioid receptor agonist that produces analgesia by mimicking endogenous opioids, increasing potassium efflux and reducing calcium influx, thereby inhibiting neuronal transmission of pain signals.
Intravenous or subcutaneous: 0.5-2 mg (0.1-0.2 mg/kg for severe pain) every 2-3 hours as needed; not to exceed 20 mg/day.
SUBSYS (fentanyl buccal soluble film) is indicated for breakthrough pain in opioid-tolerant patients. Initial dose: 100 mcg (one 100 mcg film) placed on the inner cheek, allowed to dissolve over 15-25 minutes; may repeat once after 30 minutes if pain not relieved. Titrate to effective dose (200, 400, 600, 800, 1200, 1600 mcg). Maximum: 4 doses per day. No more than 2 doses per breakthrough pain episode. Wait at least 2 hours before treating next episode.
None Documented
None Documented
Terminal elimination half-life is 2–3 hours in adults; prolonged to 3–4 hours in elderly and up to 15 hours in patients with severe hepatic impairment.
Terminal half-life 2–4 hours (single dose); prolonged to 7–15 hours in hepatic/renal impairment; clinical context: necessitates q4–6h dosing for chronic pain.
Primarily renal (approximately 70% as unchanged drug, <5% as noroxymorphone and other conjugates); biliary/fecal excretion accounts for ~20%.
Primarily renal (~75% as metabolites, <10% unchanged); biliary/fecal excretion of conjugates; ~9% in feces.
Category C
Category C
Opioid Analgesic
Opioid Analgesic