What is the dosage for propoxyphene?

The recommended adult dose is 1 capsule (65 mg) or 1 tablet (100 mg) every 4 hours as needed for relief of pain. Doses should not exceed 390 mg (capsule) or 600 mg (tablets) in a 24-hour period.

Which drugs or supplements interact with propoxyphene?

Propoxyphene, like other narcotic pain-relievers, increases the effect of drugs that slow brain function, such as alcohol, barbiturates, skeletal muscle relaxants, for example, carisoprodol (Soma) and cyclobenzaprine (Flexeril), and benzodiazepine sedatives, for example, diazepam (Valium) and lorazepam (Ativan). Combined use of muscle relaxants and propoxyphene may lead to increased respiratory depression.

Combining propoxyphene with carbamazepine (Tegretol, Tegretol XR, Equetro, Carbatrol) may have extreme effects on the brain including coma.

Since propoxyphene causes constipation, the use of antidiarrheals, for example, diphenoxylate (Lomotil) and loperamide (Imodium), in persons taking propoxyphene, can lead to severe constipation.

Drugs which both stimulate and block opioid receptors, for example pentazocine (Talwin), nalbuphine (Nubain), butorphanol (Stadol), and buprenorphine (Buprenex) may reduce the effect of propoxyphene and may precipitate propoxyphene withdrawal symptoms.

The metabolism of propoxyphene may be altered by strong CYP3A4 inhibitors (such as ritonavir, ketoconazole, itraconazole, troleandomycin, clarithromycin, nelfinavir, nefazadone, amiodarone, amprenavir, aprepitant, diltiazem, erythromycin, fluconazole, fosamprenavir, grapefruit juice, and verapamil) leading to enhanced propoxyphene plasma levels. Patients receiving propoxyphene and any CYP3A4 inhibitor should be carefully monitored for an extended period of time and dosage adjustments should be made if warranted.