propoxyphene (Darvon, Dolene)

Propoxyphene is indicated for the relief of mild to moderate pain.

It 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?

Yes

Do I need a prescription for propoxyphene?

Yes

WARNING

There have been numerous cases of accidental and intentional overdose with propoxyphene products either alone or in combination with other CNS depressants, including alcohol.

Fatalities within the first hour of overdosage are not uncommon.

Many of the propoxyphene-related deaths have occurred in patients with previous histories of emotional disturbances or suicidal ideation/attempts and/or concomitant administration of sedatives, tranquilizers, muscle relaxants, antidepressants, or other CNS-depressant drugs. Do not prescribe propoxyphene for patients who are suicidal or have a history of suicidal ideation.

Common side effects

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.

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.

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.

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 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).