Comparative Pharmacology
Head-to-head clinical analysis: DARVON versus DILAUDID HP.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON versus DILAUDID HP.
DARVON vs DILAUDID-HP
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Hydromorphone is a full mu-opioid receptor agonist with high affinity for mu-opioid receptors, producing analgesia, euphoria, and sedation. It also binds to kappa and delta opioid receptors with lower affinity.
Propoxyphene hydrochloride (Darvon) for moderate to severe pain: 65 mg orally every 4 hours as needed; maximum 390 mg/day.
Initial dose: 0.2-0.6 mg IV/IM/SC every 2-4 hours as needed; usual adult dose: 0.2-0.4 mg IV/IM/SC. Oral: 1-2 mg every 3-6 hours. Dose titration based on pain severity.
None Documented
None Documented
6-12 hours (parent drug); norpropoxyphene half-life 30-36 hours, accumulates with repeated dosing, increasing risk of toxicity.
Terminal elimination half-life: 2.3–4 hours. In clinical context, consistent with dosing interval of 4–6 hours for immediate-release formulations; prolonged in hepatic or renal impairment.
Primarily hepatic metabolism to norpropoxyphene, then renal excretion of metabolites; <20% excreted unchanged in urine; minor biliary/fecal elimination.
Renal: predominantly as hydromorphone-3-glucuronide (H3G), unchanged hydromorphone (<6%), and other metabolites. Biliary/fecal: minimal.
Category C
Category C
Opioid Analgesic
Opioid Analgesic