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 using methadone can either be done 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 in people with normal liver function. Methadone is usually taken by mouth and rarely by injection into a muscle or vein
Side effects are similar to those of other opioids. Commonly these include dizziness, sleepiness, vomiting, and sweating. Serious risks include opioid abuse or a decreased effort to breathe. Abnormal heart rhythms 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.
Methadone was developed in Germany around 1937 to 1939 by Gustav Ehrhart and Max Bockmühl. It was approved for use in the United States in 1947. Methadone is on the World Health Organization’s List of Essential Medicines, the most effective and safe medicines needed in a health system. Globally in 2013, about 41,400 kilograms were manufactured. It is regulated similarly to other narcotic drugs. In the United States it is not very expensive.