Comparative Pharmacology
Head-to-head clinical analysis: BUTRANS versus DARVON.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BUTRANS versus DARVON.
BUTRANS vs DARVON
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Buprenorphine is a partial mu-opioid receptor agonist and a weak kappa-opioid receptor antagonist. It binds with high affinity to mu-opioid receptors, producing analgesic and opioid effects with a ceiling effect on respiratory depression.
Propoxyphene is a mu-opioid receptor agonist that inhibits ascending pain pathways by binding to opioid receptors in the CNS, altering pain perception. It also has weak local anesthetic effects.
Apply one BUTRANS (buprenorphine) transdermal system to a clean, dry, non-irritated, and non-hairy area of the chest, back, flank, or upper arm. Initial dose: 5 mcg/h for opioid-naïve patients; titrate based on pain control and tolerability. Maximum dose: 20 mcg/h. Replace every 7 days. Rotate application sites.
Propoxyphene hydrochloride (Darvon) for moderate to severe pain: 65 mg orally every 4 hours as needed; maximum 390 mg/day.
None Documented
None Documented
Terminal half-life: 4-6 hours in healthy adults; prolonged to 12-18 hours in elderly or renal impairment
6-12 hours (parent drug); norpropoxyphene half-life 30-36 hours, accumulates with repeated dosing, increasing risk of toxicity.
Renal: 60-70% as unchanged drug and metabolites; biliary/fecal: 20-30%
Primarily hepatic metabolism to norpropoxyphene, then renal excretion of metabolites; <20% excreted unchanged in urine; minor biliary/fecal elimination.
Category C
Category C
Opioid Analgesic
Opioid Analgesic