Partial agonists benzodiazepine receptor interactions with

This section describes the partial agonists and the nonbenzodiazepine drugs that act at the benzodiazepine receptor. What these drugs have in common is that their development has been driven by the search for effective anxiolytics that do not have the adverse effects of sedation, amnesia, ataxia, interaction with alcohol, or the problems of tolerance, dependency, and withdrawal seen with classic benzodiazepines. These problems have been addressed by the development of partial agonists, subtype-selective ligands, and other drugs, the cyclopyrrolones, which do not seem to cause these problems. 

Buspirone is a partial agonist at serotonin type 1A (5-HTj ) receptors. Unlike benzodiazepines, barbiturates, and alcohol, buspirone does not interact with the GABA receptor or chloride ion channels. Thus, it does not produce sedation, interact with alcohol, impair psychomotor performance, or pose a risk of abuse. There is no cross-tolerance between benzodiazepines and buspirone, so benzodiazepines cannot be abruptly replaced with buspirone. Likewise, buspirone cannot be used to treat alcohol or barbiturate withdrawal and detoxification. Like the antidepressants, buspirone has a relatively slow onset of action. 

It belongs to azapirones which is chemically and pharmacologically distinct class. It acts as a partial agonist at serotonin and dopamine receptors and having no hypnotic and sedative action. It does not interact with benzodiazepine receptor or modify GABA-ergic transmission. 

Buspirone has selective anxiolytic effects, and its pharmacologic characteristics are different from those of other drugs described in this chapter. Buspirone relieves anxiety without causing marked sedative, hypnotic, or euphoric effects. Unlike benzodiazepines, the drug has no anticonvulsant or muscle relaxant properties. Buspirone does not interact directly with GABAergic systems. It may exert its anxiolytic effects by acting as a partial agonist at brain 5-HTia receptors, but it also has affinity for brain dopamine D2 receptors. Buspirone-treated patients show no... 

Other drugs The anxiolytic ding buspirone interacts with the S-HT, subclass of brain serotonin receptors as a partial agonist, but the precise mechanism of its anxiolytic effect is unknown. The hypnotics zolpidem and zaleplon are not benzodiazepines but appear to exert their CNS effects via interaction with certain benzodiazepine receptors, classified as BZ, or omega, subtypes their CNS depressant effects are antagonized by flumazenil. 

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