Calcium channels. Interactions with ethanol and other sedative-hypnotic drugs.

Biochemical and electrophysiological studies have shown that ethanol potently inhibits voltage-dependent calcium channels in presynaptic nerve terminals in brain. The ability of ethanol to inhibit calcium channels appears to vary from one brain region to another. Chronic ethanol administration results in adaptation of the calcium channels in certain brain regions such that they become tolerant to the inhibitory actions of ethanol. Other sedative-hypnotic drugs, such as barbiturates and benzodiazepines, also inhibit calcium channels but may differ from ethanol in their brain regional potency. These studies suggest that the pharmacological actions of ethanol and other sedative-hypnotic drugs may be linked with alterations in calcium channel function.