Levomethadone (INN; L-Polamidon, L-Polamivet, Levadone, Levothyl), or levamethadone, is a synthetic opioid analgesic and antitussive which is marketed in Europe and is used for pain management and in opioid maintenance therapy. In addition to being used as a pharmaceutical drug itself, levomethadone, or R-(−)-methadone, is the active enantiomer of methadone, having 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 of the N-methyl-D-aspartate (NMDA) receptor complex and as a potent noncompetitive antagonist of the α3β4 nicotinic acetylcholine (nACh) receptor.

CAS：5967-73-7
中文别名：
英文别名：(-)-Mephobarbital;(R)-(6-dimethylamino-4,4-diphenylheptan-3-one) hydrochloride;UNII-5NC67NU76B component ALARQZQTBTVLJV-CYBMUJFWSA-N;(R)-6-dimethylamino-4,4-diphenyl-3-heptanone hydrochloride;(-)-Methadone hydrochloride;(-)-Methylphenobarbital;(6R)-methadone hydrochloride;(R)-Methylphenobarbital;(5S)-mephobarbital;2,4,6(1H,3H,5H)-Pyrimidinetrione,5-ethyl-1-methyl-5-phenyl-,(R);(R)-(-)-mephobarbital;R-(-)-methadone hydrochloride;
分子式：C21H28ClNO
分子量：345.906
精确质量：345.186
Psa：20.31
Logp：5.094

UNII：V57LC776C0

沸点：423.7ºC at 760 mmHg
熔点：220-227ºC
闪点：126.5ºC
储存条件：Controlled Substance, -20ºC Freezer