Attenuation of ketamine effects by nimodipine pretreatment in recovering ethanol dependent men: psychopharmacologic implications of the interaction of NMDA and L-type calcium channel antagonists.

Ketamine blocks the calcium channel associated with N-methyl-D-aspartate (NMDA) glutamate receptors. It has transient behavioral effects in healthy humans that resemble aspects of schizophrenia, dissociative disorders, and ethanol intoxication. Ethanol is an antagonist of both NMDA receptors and L-type voltage-sensitive calcium channels (VSCC) and it has minimal psychotogenic activity in humans. A double-blind placebo-controlled study was conducted that evaluated whether pretreatment with the L-type VSCC antagonist, nimodipine, 90 mg D, modulated ketamine response (bolus 0.26 mg/kg, infusion of 0.65 mg/kg/hr) in 26 ethanol-dependent inpatients who were sober for at least one month prior to testing. This study found that nimodipine reduced the capacity of ketamine to induce psychosis, negative symptoms, altered perception, dysphoria, verbal fluency impairment, and learning deficits. Nimodipine improved memory function, but had no other intrinsic behavioral activity in this patient group. Nimodipine pretreatment attenuated the perceived similarity of ketamine effects to ethanol as well as ketamine-induced euphoria and sedation. However, nimodipine did not reduce the stimulant effects of ketamine. These data suggest that antagonism of L-type VSCCs attenuates the behavioral effects of NMDA antagonists in humans. They support the continued evaluation of nimodipine in the treatment of neuropsychiatric disorders. They also suggest that drugs, such as ethanol, that combine NMDA and L-type VSCC antagonism may have enhanced tolerability without attenuation of their stimulant effects.

[Ethanol inhibits platelet monoamine oxidase type B activity in patients with alcoholism]. / Ingibiruiushchee deistvie étanola na aktivnost' monoaminoksidazy tipaB trombitsitov u bol'nykh alkogolizmom.

The influence of 400 mM ethanol on the activity of monoamine oxidase type B (MAO-B) of blood platelets has been studied in vitro in 30 alcoholic patients and 30 healthy volunteers. Benzylamine was used as a substrate for MAO-B. MAO-B inhibition by ethanol was higher in alcoholics compared to healthy volunteers. The higher vulnerability of MAO-B of alcoholics inhibiting action to of ethanol may be one of the mechanisms underlying some symptoms of alcoholism.

[The relation of psychological characteristics of alcoholics and indices of discrete omega measurement]. / Sviaz' mezhdu psikhologicheskimi kharakteristikami bol'nykh alkogolizmom i pokazateliami diskretnoi omegametrii.

As a result of factor analysis of discrete omega measurement data and psychological studies of 62 chronic alcoholic patients the interconnection was found between one of super-slow physiological process in the brain--omega potential and individual-typological characteristics of personality according to the tests of Spilberger-Khanin, Rosenzweig and MMPI. The obtained results allow to consider the methods of discrete omega measurement with psychoemotional load in the form of imitation of alcohol usage as an objective means of express-test of alcoholic patients psychological state.