Buspar (Buspirone)

• Generic name: buspirone
• Trade names: Buspar, Buspirex, Vanspar
• Pharmacologic category: Antianxiety, Anxiolytic, Azapirones
• Manufacturer: Bristol Myers SQUIBB
• FDA approved: September 29, 1986
• Habit forming? Probably not

Buspar is a psychotropic drug with anxiolytic properties which belongs chemically to the class of compounds known as the azaspirodecanediones. Buspirone is used to treat nervousness, anxiety, and obsessive-compulsive disorders. However, it may be ineffective for panic attacks and usually is not used for tension caused by the stress of everyday life.

Buspirone may help to feel less nervous and irritable, and may control symptoms such as trouble sleeping, sweating, and pounding heartbeat. This drug has slow onset of action and works gradually over a two to four week period.

Buspirone may reduce anger and aggression and appears to be less likely than benzodiazepines to cause disinhibition.

Limit the amount of grapefruit during the treatment. Grapefruit may increase the amount of buspirone in the bloodstream.

• Absorption: rapidly and almost completely absorbed from the GI tract.
• Elimination half-life: 2.4 hours (range: 2-11 hours)
• Metabolism: Hepatic via oxidation; extensive first-pass effect
• Excretion: Urine: 65%; feces: 35%; about 1% excreted unchanged

• Low potential for cognitive or motor impairment
• Not addictive, even with long-term use
• No significant withdrawal symptoms, even when the drug is discontinued quickly
• Well tolerated by elderly people

• Management of aggression in mental retardation and secondary mental disorders
• Depression
• Augmenting agent for antidepressants
• Premenstrual syndrome
• ADHD

Buspirone, an azpirone derivative, has a high affinity for serotonin 5-HT1A and 5-HT2 receptors, without affecting benzodiazepine-GABA receptors. It has moderate affinity for dopamine D2 receptors.

Its distinctive mechanism of action contributes towards a superior safety profile with generally more endurable adverse effects. Does not substantially impair psychomotor function, and produces only minor sedation (drowsiness or fatigue). As an anxiolytic it is approximately equivalent to diazepam.

Compared with the benzodiazepines, buspirone has no immediate effects, works slowly, and does not cause euphoria. It must be taken consistently for at least 2 weeks to achieve an antianxiety effect and therefore cannot be used on an "as-needed" basis.

Because buspirone has a negligible potential for abuse, it is useful in persons whose anxiety coexists with alcoholism. Some experts believe it may be useful for adolescents and children. Common side effects include dizziness, drowsiness, and nausea. Persons after the treatment with benzodiazepines may respond less well to buspirone than others.