Methadone Toxicity | Suite101.com

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Elaine Moore
Dec 2, 2006

In recent years, the drug methadone, which traditionally has been used to reduce cravings for opiates in heroin addicts, has been used to reduce pain in patients with chronic diseases including autoimmune disorders. However, on November 27, 2006, the FDA issued a public health advisory urging physicians to carefully monitor patients using methadone for pain following reports of overdoses that led to life-threatening side effects and death. The FDA also has recommended that methadone be prescribed exclusively for patients with moderate to severe pain who have not responded to other pain relievers. Physicians are also advised to familiarize themselves with the effects of methadone toxicity to recognize early symptoms of overdose. The use of methadone in patients with chronic pain can lead to shallow breathing, and dangerous changes in heartbeat.

The risk of methadone toxicity is related to its ability to remain in the system for as long as 59 hours following a single dose. Because pain relief with methadone typically lasts no more than eight hours patients may not realize that methadone is still in their system. Patients may not realize that taking additional doses can have cumulative biochemical actions. One of the earliest reports of methadone related fatalities, released in December of 1992, described methadone toxicity causing death in ten patients on a methadone maintenance program.

In the 16th century, Paracelsus stated, "All substances are poisons. The right dose differentiates a poison and a remedy." In methadone toxicity, doses that are too high for the individual cause respiratory depression, which can contribute to bronchopneumonia. Used in combination with alcohol or tranquilizers, methadone can also lead to hepatitis and kidney disease. Because of its long half-life, methadone may have a delayed onset of activity, causing patients to increase their dose with the innocent intention of relieving pain. Because methadone does not cause the euphoric "high" associated with opiates, patients may not realize the potential for drug toxicity.

Resources:

Health Care Advisory Board Daily Briefing, November 28, 2006.

Drummer OH, Opeskin K, Syrjanen M, Cordner SM, Methadone toxicity causing death in ten subjects starting on a methadone maintenance program, American journal of Forensic Medical Pathology, December 1992; 13(4): 346-350.