Buspirone is used for the management of anxiety disorders (anxiety and phobic neuroses) and for short-term relief of symptoms of anxiety. Anxiety or tension associated with the stress of everyday life usually does not require treatment with an anxiolytic. The efficacy of buspirone for long-term use (i.e., longer than 3-4 weeks) as an anxiolytic has not been established by controlled studies, but the drug has been used in some patients for substantially longer periods (e.g., 6-12 months) without apparent loss of clinical effect. If the drug is used for extended periods, the need for continued therapy should be reassessed periodically.
Generalized Anxiety Disorder
Efficacy of buspirone has been established principally in outpatient settings for the management of generalized anxiety disorder in which anxiety was present for periods of 1 month up to 1 year (average symptom duration: 6 months) of continual duration. Generalized anxiety disorder is characterized principally by unrealistic or excessive anxiety and worry (apprehensive expectation) about 2 or more life circumstances (e.g., worry about possible misfortune to a child who is in no danger, worry about personal finances for no good reason, anxiety and worry about academic, athletic, and/or social performance). The disorder is manifested as symptoms of motor tension (e.g., trembling, twitching, shakiness, muscle tension, restlessness), autonomic hyperactivity (e.g., sweating, palpitation and/or tachycardia, dyspnea, dry mouth, dizziness, clammy hands, hot flushes [ flashes]), and vigilance and scanning (e.g., hyperattentativeness, feeling keyed up or on edge, difficulty concentrating, insomnia, irritability). Although patients with generalized anxiety disorder may have another underlying mental disorder (axis I disorder), the focus of the anxiety and worry is unrelated to the latter disorder. In addition, symptoms of generalized anxiety disorder should not occur only during the course of a mood or psychotic disorder, nor should the anxiety be initiated and maintained by an underlying organic factor (e.g., hyperthyroidism, caffeine intoxication).
Controlled studies in patients with generalized anxiety disorder have shown that buspirone at usual dosages is as effective as usual dosages of benzodiazepines (e.g., alprazolam, clorazepate, diazepam, lorazepam) and more effective than placebo in reducing symptoms associated with anxiety. Limited evidence suggests that buspirone may be more effective for cognitive and interpersonal problems, including anger and hostility, associated with anxiety, while benzodiazepines may be more effective for somatic symptoms of anxiety. The drug also has been shown to reduce symptoms of anxiety in patients with coexisting depressive symptoms. Buspirone therapy generally is associated with fewer and less severe adverse CNS effects (e.g., sedation, psychomotor impairment) compared with benzodiazepines and appears to have little, if any, dependence liability. Because of these differences, buspirone may be preferred as initial therapy in some patients with generalized anxiety disorder. The drug may be particularly useful in patients in whom potential adverse effects of benzodiazepines would be of concern (e.g., patients whose work or life-style requires mental acuity, geriatric patients who may be particularly sensitive to the adverse CNS effects of benzodiazepines) and/or those in whom the abuse potential, dependence liability, and/or potential withdrawal associated with benzodiazepines are of concern. In addition, buspirone may be safer than benzodiazepines in those patients with anxiety disorders who, despite all warnings, are considered likely to combine anxiolytic therapy with CNS depressants and/or alcohol.
(See Drug Interactions: Alcoholand also Other CNS Depressants.)
In addition to symptoms of anxiety, buspirone has reduced depressive symptoms in patients with generalized anxiety disorder, as determined using the Hamilton (HAM-D) or Raskin depression rating scale. Buspirone generally has been as effective as benzodiazepines in relieving symptoms of depression in these patients, although the drug may be less effective than benzodiazepines in relieving sleep disturbances. It has been suggested that improvement in depressive symptoms observed in these patients actually may reflect improvement in anxiety symptoms that are included in the depression rating scales rather than an antidepressant effect per se, and additional study is needed to determine whether the drug has clinically important antidepressant activity. Buspirone also has been used in combination with antidepressants in a limited number of patients with symptoms of both anxiety and depression.
Symptoms of Sexual Dysfunction
The efficacy of buspirone for the management of sexual dysfunction in patients with generalized anxiety disorder has not been established, but limited data suggest that the drug may improve sexual function in these patients. Although the improvement in sexual function paralleled improvement in anxiety in one study, other mechanisms may have been involved. Further study is needed to more fully elucidate the value of buspirone in these patients.
Other Anxiety Disorders
Because buspirone may diminish anger and hostility and appears to be less likely than benzodiazepines to cause disinhibition, some clinicians suggest that buspirone may be preferred in patients with a history of aggression or in whom disinhibition has occurred during benzodiazepine therapy. Benzodiazepines may be preferred as initial therapy in patients with anxiety symptoms (e.g., insomnia, muscle tension) that might benefit from the sedative and/or muscle relaxant effects of these drugs. If buspirone is used in patients whose anxiety includes insomnia as a component, concomitant use of a sedative/hypnotic at bedtime may be necessary. Because buspirone may have a slower onset of action than some anxiolytics (e.g., diazepam)
(see Dosage and Administration: Dosage), patients may become discouraged during initial therapy with the drug, particularly when buspirone is used for the short-term management of anxiety associated with severe stress.
The influence of previous, long-term benzodiazepine therapy on the anxiolytic response to buspirone remains to be fully elucidated, but response may be discouraging in some patients, possibly because buspirone has a slower onset of action and does not attenuate manifestations of benzodiazepine withdrawal. In addition, the anxiolytic expectations of some patients who previously have received long-term benzodiazepine therapy may differ considerably from the actual effects of buspirone therapy, which also could contribute to a discouraging response to buspirone in such patients. Because of the sometimes discouraging response to buspirone in such patients, some clinicians suggest that newly diagnosed patients and those with no previous benzodiazepine use may be optimal candidates for buspirone therapy.
Efficacy of buspirone in the management of panic attacks or disorder has not been established.
Results of an uncontrolled study suggest that relatively high dosages of buspirone hydrochloride (i.e., usually 40-60 but up to 90 mg daily) may provide some reduction in depressive symptoms in patients with major depression (nonmelancholic type), but not in patients whose major depression is of the melancholic type. Well-controlled studies, particularly those comparing buspirone with antidepressants, are necessary to determine whether buspirone has clinically important antidepressant activity.
Although buspirone exhibited some evidence of neuroleptic potential in several animal models and reportedly has produced transient antipsychotic effects when administered in large doses to patients with schizophrenia, the drug has no established antipsychotic activity in humans at usual dosages and should not be used in place of appropriate antipsychotic therapy when such therapy is indicated.
Because of buspirone's effects on dopamine receptors, the drug has been studied for potential therapeutic effects in patients with parkinsonian syndrome. At dosages of 10-70 mg daily, buspirone provided no clinically important improvement or deterioration in a limited number of patients with parkinsonian syndrome who were receiving antiparkinsonian therapy (e.g., levodopa/carbidopa, bromocriptine) concomitantly. At higher dosages, however, some deterioration in parkinsonian manifestations (e.g., functional disability) was observed. Therefore, current evidence indicates that buspirone is not useful in the management of parkinsonian syndrome and may exacerbate the syndrome at relatively high dosages. The drug may be useful, however, as an anxiolytic in parkinsonian patients, provided high dosages are avoided.