codeine and Substance-Related-Disorders

The basic science and clinical use of morphine and other "opioid" drugs are based almost exclusively on the extracts or analogues of compounds isolated from a single source, the opium poppy (Papaver somniferum). However, it now appears that biological diversity has evolved an alternative source. Specifically, at least two alkaloids isolated from the plant Mitragyna speciosa, mitragynine ((E)-2-[(2S,3S)-3-ethyl-8-methoxy-1,2,3,4,6,7,12,12b-octahydroindolo[3,2-h]quinolizin-2-yl]-3-methoxyprop-2-enoic acid methyl ester; 9-methoxy coryantheidine; MG) and 7-hydroxymitragynine (7-OH-MG), and several synthetic analogues of these natural products display centrally mediated (supraspinal and spinal) antinociceptive (analgesic) activity in various pain models. Several characteristics of these compounds suggest a classic "opioid" mechanism of action: nanomolar affinity for opioid receptors, competitive interaction with the opioid receptor antagonist naloxone, and two-way analgesic cross-tolerance with morphine. However, other characteristics of the compounds suggest novelty, particularly chemical structure and possible greater separation from side effects. We review the chemical and pharmacological properties of these compounds.

Topics: Administration, Oral; Analgesics, Opioid; Animals; Humans; Secologanin Tryptamine Alkaloids; Substance-Related Disorders

Topics: Animals; Aorta, Thoracic; Cocaine; Cyclic AMP; Electric Stimulation; Guinea Pigs; Humans; Ileum; In Vitro Techniques; Male; Mice; Muscle, Smooth; Opioid-Related Disorders; Rats; Receptors, Dopamine; Receptors, Opioid; Receptors, Serotonin; Substance-Related Disorders

A series of 8-alkyl-3-methoxy-17-methylmorphinan-6-ones (3C) and -isomorphinan-6-ones (3T) were prepared by conjugate addition of lithium dialkylcuprates to the corresponding 7,8-didehydro-6-ones 2C and 2T. These 17-methyl compounds were potent analgesics and were converted to mixed narcotic agonists-antagonists 7-10, by replacement of the 17-methyl groups with cycloalkylmethyl moieties. The 8 substituent modified the type of activity observed. One of these compounds, 17-(cyclobutylmethyl)-3-hydroxy-8 beta-methylmorphinan-6-one (10Ca), had an agonist-antagonist ratio of 0.1. Compound 10Ca did not support or cause dependence in rats. This compound, however, appeared to be a typical narcotic agent in morphine-dependent monkeys.

Topics: Acetates; Analgesics; Animals; Haplorhini; Humans; Mice; Morphinans; Morphine Dependence; Narcotic Antagonists; Rats; Reaction Time; Structure-Activity Relationship; Substance Withdrawal Syndrome; Substance-Related Disorders

The levo and dextro isomers of 2,5-dimethyl-2'-hydroxy-9alpha- and -9beta-propyl-6,7-benzomorphans have been prepared. The analgesic potency and physical dependence capacity of the optical isomers and their racemic parents were determined. The 9alpha-propyl levo isomer was analgesically equipotent with morphine; the 9beta-propyl levo isomer was considerably more potent subcutaneously and equipotent orally. None of the optical isomers suppressed the withdrawal syndrome; the 9beta-propyl levo isomer exacerbated the withdrawal syndrome.

Topics: Analgesics; Animals; Benzomorphans; Haplorhini; Humans; Mice; Morphinans; Morphine Dependence; Optical Rotation; Stereoisomerism; Substance-Related Disorders