Methadone accounted for nearly a third of opioid-related deaths in 2010, according to an MMWR article.

The CDC’s study of 13 states found that methadone represented 4.5% to 18.5% of all opioid prescriptions, but 31.4% of opioid-related deaths. Methadone can cause life-threatening complications through cardiac arrhythmia, cardiorespiratory depression due to its long half-life and accumulating toxic levels, and interactions with other drugs, including antianxiety drugs.

The CDC reminds clinicians of the following:

• Methadone shouldn’t be used for mild, acute, or breakthrough pain, or on an as-needed basis.
• It shouldn’t be given to patients who are opioid-naive or those taking benzodiazepine antianxiety drugs.
• Those who prescribe methadone should have substantial experience with it and adhere to guidelines for appropriate opioid prescribing.

Source: MMWR