Dextropropoxyphene

Oral
Mild to moderate pain

Dose reduction may be needed.

Dose reduction may be needed.

May be taken with or without food.

Hypersensitivity, chronic resp diseases, porphyria, pregnancy. Patients on MAOI treatment or within 2 wk of stopping treatment.

Suicidal patients, hepatic or renal disease; lactation, elderly.

Dizziness, sedation, weakness; nausea, vomiting, constipation; rash, urticaria; visual disturbances; physiological dependence.
Potentially Fatal: Convulsions in long-term therapy. Cardiac conduction abnormalities and arrhythmias; liver impairment.

PO: C

Symptoms: Coma, respiratory depression, circulatory collapse, pulmonary oedema, seizures, nephrogenic diabetes insipidus, ECG abnormalities. Death may occur as early within the 1st 15 minutes to 1 hr. Management: Intensive symptomatic and supportive therapy to be instituted immediately. IV naloxone may reverse intoxication. Induction of emesis or gastric lavage followed by activated charcoal helps to reduce absorption. Monitor blood gases, pH, electrolytes and ECG. Dialysis is unlikely to be useful.

Inhibits hepatic metabolism of benzodiazepines, β-blockers, carbamazepine, phenytoin and warfarin. Increased risk of toxicity when co-administered with ritonavir. Potentiation of depressant effects when used with alcohol or CNS depressants.
Potentially Fatal: Accidental or intentional overdosage fatal (especially if combined with alcohol, and analgesics e.g. paracetamol and aspirin).

Absorption decreased.

Description:
Mechanism of Action: Dextropropoxyphene is a relatively weak opioid analgesic which binds to mu- and kappa-receptors in order to block pain perception in the cerebral cortex. This results in inhibiton of pain sensation flow into high centers.
Pharmacokinetics:
Absorption: Readily absorbed from the GI tract; napsilate form more slowly absorbed than the HCl (oral); peak plasma concentrations after 1-2 hr.
Distribution: Concentrated in the liver, lungs and brain; crosses the placenta and small amounts enter breast milk. Protein-binding: 80%.
Metabolism: Hepatic, to nordextropropoxyphene (norpropoxyphene); undergoes 1st-pass metabolism.
Excretion: Urine (as metabolites). Elimination half-life: 6-12 hr (dextropropoxyphene), 30-36 hr (norpropoxyphene).

Store at 15-30°C.

Analgesics (Opioid)