Its molecular structure is a close relative of the synthetic narcotic, methadone. It's prescribed in two forms- propoxyphene hydrochloride and propoxyphene napsylate -for relief of mild to moderate pain.

Aside from slight differences-the napsylate (or N-form) of propoxyphene is more slowly absorbed in the body and so has a longer duration of action-the two drugs are identical. Both are found in a number of prescription pain medications, including:

• Darvon and Darvon-N (propoxyphene only)
• Darvon with A.S.A., Darvon-N with A.S.A. (with aspirin)
• Darvocet, Darvocet-N, Wygesic (with acetaminophen)
• Darvon Compound, Darvon Compound-65 (with aspirin and caffeine)

Darvocet when abused is taken orally, chewed, crushed (then snorted like cocaine), or crushed (then dissolved in water and injected like heroin).

What are the side effects of Darvocet?

The side effects of Darvocet are:

• drowsiness
• dizziness
• nausea
• sedation
• vomiting
• abdominal pain
• constipation
• feelings of elation or depression
• hallucinations
• headache
• kidney problems
• lightheadedness
• liver problems
• minor visual disturbances
• skin rashes
• weakness
• yellowed eyes and skin

What are the symptoms of Darvocet overdose?

Symptoms of a propoxyphene overdose may include:

• Bluish tinge to the skin, coma, convulsions, decreased or difficult breathing to the point of temporary stoppage, decreased heart function, extreme sleepiness, irregular heartbeat, low blood pressure, pinpoint pupils becoming dilated later, stupor
• Additional symptoms of overdose with Darvocet-N: Abdominal pain, excessive sweating, general feeling of illness, kidney failure, liver problems, loss of appetite, nausea, vomiting
• Additional symptoms of overdose with Darvon Compound-65: Confusion, deafness, excessive perspiration, headache, mental dullness, nausea, rapid breathing, rapid pulse, ringing in the ears, vertigo, vomiting

Extreme overdose may lead to unconsciousness and death.

Special information if you are pregnant or breastfeeding

Do not take these medications if you are pregnant or planning to become pregnant unless you are directed to do so by your doctor. Temporary drug dependence may occur in newborns when the mother has taken this drug consistently in the weeks before delivery. The use of Darvon Compound-65 (which contains aspirin) during pregnancy may cause problems in the developing baby or complications during delivery. Do not take it during the last 3 months of pregnancy. Darvocet-N does appear in breast milk.