Darvocet, Darvon & Tylenol: Prescription Drug Abuse & Testing:

Dextropropoxyphenes:

These are the mild analgesic agents of the opioid category which are frequently used to treat mild to moderate pain. These are also used as antitussive i.e. a medicine used to suppress or relieve coughing.

Use & Abuse:

Dextropropoxyphene, like codeine, is a weak opioid. However, approximately 10-20% of the Caucasian population is unable to metabolize codeine, so dextropropoxyphene is particularly useful with such people. In pure form, dextropropoxyphene is commonly used to ease the withdrawal symptoms in people addicted to opioids. Being very weak in comparison to the opioids that are commonly abused, dextropropoxyphene can only act as a “partial” substitute. It does not have much effect on mental cravings; however it can be effective in alleviating physical withdrawal effects, such as muscle cramps. It is widely prescribed to ease pain before, during and after an operation.

Dextropropoxyphene has been a subject to some controversy. While many physicians prescribe it for a wide range of mildly to moderately painful symptoms as well as for treatment of diarrhea, many others refuse to prescribe it, citing its highly addictive nature and limited effectiveness.

In many countries, dextropropoxyphene is available on prescription, both as a combined product (dextropropoxyphene + acetaminophen) and in pure form. These combined products are known with various names like Darvocet, Di-gesic etc.

Tylenol:

It is a popular American brand of drugs for relieving pain, reducing fever, and relieving the symptoms of allergies, cold, cough, and the flu. The active ingredient of its original, flagship product, acetaminophen (called “paracetamol” outside North America), is marketed for headaches, fever, muscle and body pain, arthritis, and joint pain. Like the words “acetaminophen” and “paracetamol”, the brand name is derived from the chemical name for the compound, N-acetyl-para-aminophenol (APAP). It is available over the counter without prescription, has few side effects, and reacts with very few medications. Acetaminophen is also found in other narcotic based analgesics such as Percocet which contains oxycodone. However, some classes of stronger pain relievers also contain codeine.

Darvon:

Darvon is a pure dextropropoxyphene preparation available in the U.S. that does not contain acetaminophen (Tylenol). It was made by Eli Lilly. It came under heavy fire in 1978 by consumer groups which said that Darvon was associated with suicide. Darvon was never withdrawn from the market, but Lilly has waged a sweeping, and largely successful, campaign among doctors, pharmacists and Darvon users to defend the drug as safe when it is used in proper doses and not mixed with alcohol.

Darvocet:

In the United States, dextropropoxyphene hydrochloric acid is available as a prescription formulation with acetaminophen (Tylenol) in ratio anywhere from 30mg / 600mg to 100mg / 650mg, respectively. These are usually named as Darvocet.

Dextropropoxyphene/Acetaminophen Testing:

A diverse array of techniques is available to test for drug abuse and Dextropropoxyphenes and/or acetaminophen containing compounds are no exception. As shown in the figure below, some amount of acetaminophen remains unchanged while rest of it forms different metabolites. Same is true for Dextropropoxyphenes and derivative compounds like Darvon.

These unchanged Dextropropoxyphenes & acetaminophen compounds and their metabolized products can be detected using any of the following methods:

Urine based Dextropropoxyphene/acetaminophen/metabolite testing
Hair follicle based Dextropropoxyphene/acetaminophen/metabolite detection
GC based Dextropropoxyphene/acetaminophen/metabolite detection
Mass spec based Dextropropoxyphene/acetaminophen/metabolite testing
Dextropropoxyphene / acetaminophen / metabolite-specific antibody based diagnostic kits

Tylenols & Darvocets can be detected by acetaminophen specific methods while Darvons can be detected by Dextropropoxyphene specific methods, be it urine/hair based, GC/MS based diagnostic techniques or Antibody based kits.