What is propoxyphene and acetaminophen? What is it used for?
Darvocet is a strong narcotic pain-reliever and cough suppressant but is weaker than other narcotics such as morphine, codeine, and hydrocodone. Propoxyphene increases pain tolerance and decreases discomfort, but the presence of pain is still apparent. In addition to pain reduction, propoxyphene also causes sedation and respiratory depression. Acetaminophen is a non-narcotic analgesic and antipyretic (fever reducer). Acetaminophen relieves pain by elevating the pain threshold. It reduces fever through its action on the heat-regulating center of the brain. The combination of propoxyphene and acetaminophen achieves greater pain relief than either taken separately. For more information on acetaminophen, please see acetaminophen (Tylenol). The FDA first approved propoxyphene/acetaminophen combinations in October 1972.
Is propoxyphene and acetaminophen available as a generic drug?
Do I need a prescription for propoxyphene and acetaminophen?
What are the side effects of propoxyphene and acetaminophen?
The most frequent adverse reactions of propoxyphene include:
- nausea, and
Other side effects include:
- constipation, and
- spasm of the ureter, which can lead to difficulty in urinating.
Darvocet can depress breathing and, therefore, is used with caution in elderly, debilitated patients, and in patients with serious lung disease.
What is the dosage for propoxyphene and acetaminophen?
The recommended adult dose is 1-2 tablets every 4 hours as needed for relief of pain. The total dose should not exceed six 100/650 mg tablets or twelve 50/325 mg tablets in a 24-hour period.
Which drugs or supplements interact with propoxyphene and acetaminophen?
Darvocet 500mg, 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 greater respiratory depression than either drug alone.
Combining propoxyphene with carbamazepine (Tegretol, Tegretol XR , Equetro, Carbatrol) may have severe 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 or may precipitate withdrawal symptoms from propoxyphene. Acetaminophen is metabolized (eliminated by conversion to other chemicals) by the liver. Therefore drugs that increase the action of liver enzymes that metabolize acetaminophen, for example, carbamazepine (Tegretol), isoniazid (INH, Nydrazid, Laniazid), and rifampin (Rifamate, Rifadin, Rimactane), reduce the levels of acetaminophen and therefore may decrease its action. Doses of acetaminophen greater than the recommended doses are toxic to the liver and may result in severe liver damage.
Cholestyramine (Questran) reduces the effect of acetaminophen by decreasing its absorption into the body from the intestine. Acetaminophen doses greater than 2275 mg per day may increase the blood thinning effect of warfarin (Coumadin) by an unknown mechanism.