Comparative Pharmacology
Head-to-head clinical analysis: ACTIQ versus DARVON N.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ACTIQ versus DARVON N.
ACTIQ vs DARVON-N
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.
Propoxyphene is a weak mu-opioid receptor agonist that produces analgesia by binding to opioid receptors in the central nervous system, altering the perception of and response to pain. Its metabolite norpropoxyphene has local anesthetic and sodium channel blocking effects, which may contribute to cardiac toxicity.
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.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
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.
Propoxyphene: 6-12 hours; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
Primarily renal as metabolites (about 75% as metabolites, <10% unchanged). Fecal excretion accounts for <9%. Biliary excretion is minor.
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Category C
Category C
Opioid Analgesic
Opioid Analgesic