Буспирон

Использование

Buspirone is an extremely specific drug that could possibly represent a new chemical class of anxiolytics—azaspirones. As an anxiolytic, its activity is equal to that of benzodiazepines; however, it is devoid of anticonvulsant and muscle relaxant properties, which are characteristic of benzodiazepines.

Определение

ChEBI: An azaspiro compound that is 8-azaspiro[4.5]decane-7,9-dione substituted at the nitrogen atom by a 4-(piperazin-1-yl)butyl group which in turn is substituted by a pyrimidin-2-yl group at the N4 position.

Биологические функции

Buspirone (BuSpar) is the first example of a class of anxiolytic agents that can relieve some symptoms of anxiety in doses that do not cause sedation. Buspirone is structurally unrelated to existing psychotropic drugs.

Общее описание

The initial compound in this series, buspirone (BuSpar), hasanxiolytic and antidepressant activities and is a partial5-HT_1A agonist. Its anxiolytic activity is reportedly causedby its ability to diminish 5-HT release (via 5-HT_1A agonism).High short-term synaptic levels of 5-HT are characteristic ofanxiety. Also, because it is a partial agonist, it can stimulatepostsynaptic receptors when 5-HT levels are low in thesynapse, as is the case in depression. Several other spironesare in development as anxiolytics and antidepressants.

Механизм действия

Although buspirone has been shown to interact with a number of neurotransmitter systems in the brain, it appears that its clinically relevant effects are mediated through interactions at the serotonin (5-hydroxytryptamine, 5-HT) 5-HT_1A receptor, where it acts as a partial agonist.

Фармаколо?гия

Buspirone is as effective as the benzodiazepines in the treatment of general anxiety. However, the full anxiolytic effect of buspirone takes several weeks to develop, whereas the anxiolytic effect of the benzodiazepines is maximal after a few days of therapy. In therapeutic doses, buspirone has little or no sedative effect and lacks the muscle relaxant and anticonvulsant properties of the benzodiazepines. In addition, buspirone does not potentiate the central nervous system depression caused by sedative–hypnotic drugs or by alcohol, and it does not prevent the symptoms associated with benzodiazepine withdrawal.

Клиническое использование

Buspirone is effective in general anxiety and in anxiety with depression.

Побочные эффекты

Like the benzodiazepines, buspirone appears to be safe even when given in very high doses. The most common side effects are dizziness, light-headedness, and headache. Abuse, dependence, and withdrawal have not been reported, and buspirone administration does not produce any cross-tolerance to the benzodiazepines. Buspirone has been reported to increase blood pressure in patients taking monoamine oxidase inhibitors, and it may increase plasma levels of haloperidol if coadministered with that agent.

Метаболизм

Buspirone is well absorbed from the gastrointestinal tract, and peak blood levels are achieved in 1 to 1.5 hours; the drug is more than 95% bound to plasma proteins. Buspirone is extensively metabolized, with less than 1% of the parent drug excreted into the urine unchanged. At least one of the metabolic products of buspirone is biologically active. The parent drug has an elimination half-life of 4 to 6 hours.