Methadone

Methadone, sold under the brand name Dolophine among others, is an opioid used to treat pain and as maintenance therapy or to help with detoxification in people with opioid dependence. Detoxification can either occur relatively rapidly in less than a month or gradually over as long as six months. While a single dose has a rapid effect, maximum effect can take five days of use. The effects last about six hours after a single dose and a day and a half after long-term use. Methadone is taken by mouth or by injection into a muscle or vein.

Side effects are similar to that of other opioids. Commonly these include dizziness, sleepiness, vomiting, and sweating. Serious risks include opioid abuse or a decreased effort to breathe. Heart arrhythmia may also occur including prolonged QT. The number of deaths in the United States involving methadone poisoning was 4,418 in 2011 which was 26% of total deaths from opioid poisoning. Risks are greater with higher doses. Methadone is made by chemical synthesis and acts on opioid receptors.