Comparative Pharmacology
Head-to-head clinical analysis: ACTIQ versus SUBSYS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ACTIQ versus SUBSYS.
ACTIQ 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, altering pain perception and response.
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.
200 mcg transmucosally, titrated upward as needed; initial dose for opioid-tolerant patients is 200 mcg, with additional doses possible after 15 minutes if needed. Maximum 4 doses per episode. At least 4 hours between episodes.
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 half-life 0.83–2 hours (mean 1.3 h) in adults; note that context: transmucosal absorption leads to rapid onset but short duration; half-life is not correlated with clinical effect due to oral transmucosal route and rapid redistribution.
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 as metabolites (about 75% as metabolites, <10% unchanged). Fecal excretion accounts for <9%. Biliary excretion is minor.
Primarily renal (~75% as metabolites, <10% unchanged); biliary/fecal excretion of conjugates; ~9% in feces.
Category C
Category C
Opioid Analgesic
Opioid Analgesic