methadone

Reduction of oxygen to unborn child due to depression of breathing Legal status

Class A(UK) Schedule II(US) Dependence Liability Moderate Routes oral, intravenous

Methadone (Symoron, Dolophine, Amidone, Methadose, Physeptone, Heptadon and many others) is a synthetic opioid, used medically as an analgesic, antitussive and a maintenance anti-addictive for use in patients on opioids. It was developed in Germany in 1937. Although chemically unlike morphine or heroin, methadone also acts on the opioid receptors and thus produces many of the same effects. Methadone is also used in managing chronic pain owing to its long duration of action and very low cost. In late 2004, the cost of a one-month supply of methadone was $240, as compared to an equivalent analgesic amount of meperidine (pethidine) at $120, up to $500 and more for hydromorphone, morphine, fentanyl, and extended-release oxycodone.

Methadone's usefulness in treatment of opioid dependence is the result of several factors. It has cross-tolerance with other opioids including heroin and morphine and a long duration of effect, with the result that oral dosing with methadone will stabilise the patient by stopping the opioid withdrawal syndrome. Secondly, it also blocks the euphoric effects of heroin, morphine, and similar drugs. As a result, properly dosed methadone patients can reduce or stop altogether their use of these substances.

Methadone is approved only for the treatment of opioid dependence. It is not intended to reduce the use of non-narcotic drugs such as cocaine, methamphetamine, or alcohol.

Today a number of pharmaceutical companies produce and distribute methadone. The racemic hydrochloride is the only form available in the United States as of March 2008. The tartrate and other salts of the laevorotary form (levomethadone, with trade names like Polamidone, Heptadon etc.) are available in Europe and elsewhere. These are more potent and lack the cardiac effects like lengthened QT interval caused by the dextrorotary form. The major producer remains Mallinckrodt, who sells bulk methadone to most of the producers of generic preparations, and also distributes its own brand name product in the form of tablets, dispersible tablets and oral concentrate under the name Methadose in the United States.[citation needed]. Contents [hide] 1 History 1.1 Origin of Dolophine name 2 Pharmacology 2.1 Mode of action 2.2 Metabolism 2.3 Route of administration 2.4 Adverse effects 2.4.1 Mortality 2.5 Tolerance and dependence 3 Withdrawal symptoms