Levomethadone, sold under the brand name L-Polamidon among others, is a

synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to: Science * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic o ...

opioid

analgesic An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It ...

and antitussive which is marketed in Europe and is used for pain management and in

opioid maintenance therapy Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid use ...

. In addition to being used as a pharmaceutical

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insuffla ...

itself, levomethadone is the main therapeutic component of methadone. Levomethadone is used for narcotic maintenance in place of, or in some cases alongside as an alternative, to racemic methadone, owing to concern about the cardiotoxic and QT-prolonging action of racemic methadone being exclusively caused by the dextrorotatory

enantiomer In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical ant ...

dextromethadone Esmethadone (; developmental code name REL-1017), also known as dextromethadone, is the (''S'')-enantiomer of methadone. It acts as an ''N''-methyl-D-aspartate receptor (NMDAR) antagonist, among other actions. Unlike levomethadone, it has low a ...

Pharmacology

Pharmacodynamics

Levomethadone has approximately 50x the potency of the ''S''-(+)-enantiomer as well as greater μ-opioid receptor selectivity. Accordingly, it is about twice as potent as methadone by weight and its effects are virtually identical in comparison. In addition to its activity at the opioid receptors, levomethadone has been found to act as a weak competitive

antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...

of the ''N''-methyl-D-aspartate (NMDA) receptor complex and as a potent noncompetitive antagonist of the α₃β₄ nicotinic acetylcholine (nACh) receptor.

Chemistry

The separation of the stereoisomers is one of the easier in organic chemistry and is described in the original patent. It involves "treatment of racemic methadone base with d-(+)-tartaric acid in an acetone/water mixture hichprecipitates almost solely the dextro-methadone levo-tartrate, and the more potent Levomethadone can easily be retrieved from the mother liquor in a high state of optical purity." There is now an asymmetric synthesis available to prepare both levomethadone (R-(−)-methadone) and

(S-(+)-methadone).

Society and culture

Generic names

''Levomethadone'' is the generic name of the drug and its .

Brand names

Levomethadone has been sold under brand names including L-Polaflux, L-Polamidon, L-Polamivet, Levadone, Levo-Methasan, Levothyl, Mevodict, Levopidon and Vistadict, among others.

Legal status

Levomethadone is listed under the Single Convention On Narcotic Drugs 1961 and is a Schedule II Narcotic controlled substance in the US as an isomer of methadone (ACSCN 9250) and is not listed separately, nor is dextromethadone. It is similarly controlled under the German Betäubungsmittelgesetz and similar laws in practically every other country.

References

{{Navboxes , title = Pharmacodynamics , titlestyle = background:#ccccff , list1 = {{Glycine receptor modulators {{Ionotropic glutamate receptor modulators {{Nicotinic acetylcholine receptor modulators {{Opioid receptor modulators Analgesics Antitussives Dimethylamino compounds Drug rehabilitation Glycine receptor antagonists Ketones Mu-opioid receptor agonists Nicotinic antagonists NMDA receptor antagonists Synthetic opioids