What is propoxyphene, and how does it work (mechanism of action)?

Propoxyphene is a narcotic pain-reliever and cough suppressant but is weaker than morphine, codeine, and hydrocodone. The precise mechanism of action is not known but may involve stimulation of opioid (narcotic) receptors in the brain. Propoxyphene increases pain tolerance and decreases discomfort but the presence of pain still is apparent. In addition to pain reduction, propoxyphene also causes sedation and respiratory depression. The FDA approved propoxyphene in August 1957.

What brand names are available for propoxyphene?

Darvon, Darvon-N, Dolene

Is propoxyphene available as a generic drug?

GENERIC AVAILABLE: Yes

Do I need a prescription for propoxyphene?

Yes

What are the side effects of propoxyphene?

The most frequent adverse reactions of propoxyphene include lightheadedness, dizziness, sedation, nausea, and vomiting. Other side effects include drowsiness, constipation, and spasm of the ureter, which can lead to difficulty in urinating.

Propoxyphene can depress breathing and should be used with caution in elderly, debilitated patients and in patients with serious lung disease. Propoxyphene can impair thinking and the physical abilities required for driving or operating machinery. Propoxyphene may be habit forming. Mental and physical dependence can occur but are unlikely when used for short-term pain relief.

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.

Is propoxyphene safe to take if I'm pregnant or breastfeeding?

There are no adequate studies of propoxyphene in pregnant women.

Low concentrations of propoxyphene have been measured in the breast milk of mothers taking propoxyphene. It is not known whether these small amounts can cause side effects in nursing infants.

What else should I know about propoxyphene?

What preparations of propoxyphene are available?

Tablet: 100 mg; Capsules: 65 mg

How should I keep propoxyphene stored?

Capsules and tablets should be stored at room temperature, between 15- 30 C (59-86 F).