Buspirone Hydrochloride (3 brand names, 2 dosage forms, 1 route)
Available dosage forms: TABLET, CAPSULE.
Routes of administration: ORAL.
Brand Names
- BUCAPSOL
- BUSPAR
- BUSPIRONE HYDROCHLORIDE
Indications and Usage
Buspirone hydrochloride tablets are indicated for the management of anxiety disorders or the short-term relief of the 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 hydrochloride tablets have been demonstrated in controlled clinical trials of outpatients whose diagnosis roughly corresponds to Generalized Anxiety Disorder (GAD). Many of the patients enrolled in these studies also had coexisting depressive symptoms and buspirone hydrochloride tablets relieved anxiety in the presence of these coexisting depressive symptoms. The patients evaluated in these studies had experienced symptoms for periods of 1 month to over 1 year prior to the study, with an average symptom duration of 6 months. Generalized Anxiety Disorder (300.02) is described in the American Psychiatric Association’s Diagnostic and Statistical Manual, III1 as follows: Generalized, persistent anxiety (of at least 1 month continual duration), manifested by symptoms from three of the four following categories: 1. Motor tension: Shakiness, jitteriness, jumpiness, trembling, tension, muscle aches, fatigability, inability to relax, eyelid twitch, furrowed brow, strained face, fidgeting, restlessness, easy startle. 2. Autonomic hyperactivity: Sweating, heart pounding or racing, cold, clammy hands, dry mouth, dizziness, lightheadedness, paresthesias (tingling in hands or feet), upset stomach, hot or cold spells, frequent urination, diarrhea, discomfort in the pit of the stomach, lump in the throat, flushing, pallor, high resting pulse and respiration rate. 3. Apprehensive expectation: Anxiety, worry, fear, rumination, and anticipation of misfortune to self or others. 4. Vigilance and scanning: Hyperattentiveness resulting in distractibility, difficulty in concentrating, insomnia, feeling “on edge,” irritability, impatience. The above symptoms would not be due to another mental disorder, such as a
Dosage and Administration
The recommended initial dose is 15 mg daily (7.5 mg b.i.d.). To achieve an optimal therapeutic response, at intervals of 2 to 3 days the dosage may be increased 5 mg per day, as needed. The maximum daily dosage should not exceed 60 mg per day. In clinical trials allowing dose titration, divided doses of 20 mg to 30 mg per day were commonly employed. The bioavailability of buspirone is increased when given with food as compared to the fasted state (see CLINICAL PHARMACOLOGY ). Consequently, patients should take buspirone in a consistent manner with regard to the timing of dosing; either always with or always without food. When buspirone is to be given with a potent inhibitor of CYP3A4, the dosage recommendations described in the PRECAUTIONS: Drug Interactions section should be followed. Switching a Patient To or From a Monoamine Oxidase Inhibitor (MAOI) Antidepressant At least 14 days should elapse between discontinuation of an MAOI intended to treat depression and initiation of therapy with buspirone hydrochloride tablets. Conversely, at least 14 days should be allowed after stopping buspirone hydrochloride tablets before starting an MAOI antidepressant CONTRAINDICATIONS and DRUG INTERACTIONS ). Use of Buspirone Hydrochloride Tablets with (Reversible) MAOIs, Such as Linezolid or Methylene Blue Do not start buspirone hydrochloride tablets in a patient who is being treated with a reversible MAOI such as linezolid or intravenous methylene blue because there is an increased risk of serotonin syndrome. In a patient who requires more urgent treatment of a psychiatric condition, non-pharmacological interventions, including hospitalization, should be considered (see CONTRAINDICATIONS and DRUG INTERACTIONS ). In some cases, a patient already receiving therapy with buspirone hydrochloride tablets may require urgent treatment with linezolid or intravenous methylene blue. If acceptable alternatives to linezolid or intravenous methylene blue treatment are not available and the p
Contraindications
Buspirone hydrochloride tablets are contraindicated in patients hypersensitive to buspirone hydrochloride. The use of monoamine oxidase inhibitors (MAOIs) intended to treat depression with buspirone or within 14 days of stopping treatment with buspirone is contraindicated because of an increased risk of serotonin syndrome and/or elevated blood pressure. The use of buspirone within 14 days of stopping an MAOI intended to treat depression is also contraindicated. Starting buspirone in a patient who is being treated with reversible MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome. (see WARNINGS , DOSAGE AND ADMINISTRATION and DRUG INTERACTIONS )
Adverse Reactions
(SEE ALSO PRECAUTIONS) Commonly Observed: The more commonly observed untoward events associated with the use of buspirone hydrochloride tablets not seen at an equivalent incidence among placebo-treated patients include dizziness, nausea, headache, nervousness, lightheadedness, and excitement. Associated with Discontinuation of Treatment: One guide to the relative clinical importance of adverse events associated with buspirone hydrochloride tablets are provided by the frequency with which they caused drug discontinuation during clinical testing. Approximately 10% of the 2200 anxious patients who participated in the buspirone hydrochloride tablets premarketing clinical efficacy trials in anxiety disorders lasting 3 to 4 weeks discontinued treatment due to an adverse event. The more common events causing discontinuation included: central nervous system disturbances (3.4%), primarily dizziness, insomnia, nervousness, drowsiness, and lightheaded feeling; gastrointestinal disturbances (1.2%), primarily nausea; and miscellaneous disturbances (1.1%), primarily headache and fatigue. In addition, 3.4% of patients had multiple complaints, none of which could be characterized as primary. Incidence in Controlled Clinical Trials: The table that follows enumerates adverse events that occurred at a frequency of 1% or more among buspirone hydrochloride patients who participated in 4 week, controlled trials comparing buspirone hydrochloride tablets with placebo. The frequencies were obtained from pooled data for 17 trials. The prescriber should be aware that these figures cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those which prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses, and investigators. Comparison of the cited figures, however, does prov
Drug Interactions
Psychotropic Agents: MAO inhibitors: The use of monoamine oxidase inhibitors (MAOIs) intended to treat depression with buspirone or within 14 days of stopping treatment with buspirone is contraindicated because of an increased risk of serotonin syndrome and/or elevated blood pressure. The use of buspirone within 14 days of stopping an MAOI intended to treat depression is also contraindicated. Starting buspirone in a patient who is being treated with reversible MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome. (see WARNINGS , DOSAGE AND ADMINISTRATION and CONCOMITANT DRUG ) Amitriptyline: After addition of buspirone to the amitriptyline dose regimen, no statistically significant differences in the steady-state pharmacokinetic parameters (Cmax, AUC, and Cmin) of amitriptyline or its metabolite nortriptyline were observed. Diazepam: After addition of buspirone to the diazepam dose regimen, no statistically significant differences in the steady-state pharmacokinetic parameters (Cmax, AUC, and Cmin) were observed for diazepam, but increases of about 15% were seen for nordiazepam, and minor adverse clinical effects (dizziness, headache, and nausea) were observed. Haloperidol: In a study in normal volunteers, concomitant administration of buspirone and haloperidol resulted in increased serum haloperidol concentrations. The clinical significance of this finding is not clear. Nefazodone: [see Inhibitors and Inducers of Cytochrome P450 3A4 (CYP3A4)]. Trazodone: There is one report suggesting that the concomitant use of Desyrel®# (trazodone hydrochloride) and buspirone may have caused 3- to 6-fold elevations on SGPT (ALT) in a few patients. In a similar study attempting to replicate this finding, no interactive effect on hepatic transaminases was identified. Triazolam/Flurazepam: Coadministration of buspirone with either triazolam or flurazepam did not appear to prolong or intensify the sedative ef
Overdosage
Signs and Symptoms: In clinical pharmacology trials, doses as high as 375 mg/day were administered to healthy male volunteers. As this dose was approached, the following symptoms were observed: nausea, vomiting, dizziness, drowsiness, miosis, and gastric distress. A few cases of overdosage have been reported, with complete recovery as the usual outcome. No deaths have been reported following overdosage with buspirone hydrochloride tablets alone. Rare cases of intentional overdosage with a fatal outcome were invariably associated with ingestion of multiple drugs and/or alcohol, and a causal relationship to buspirone could not be determined. Toxicology studies of buspirone yielded the following LD50 values: mice, 655 mg/kg; rats, 196 mg/kg; dogs, 586 mg/kg; and monkeys, 356 mg/kg. These dosages are 160 to 550 times the recommended human daily dose. Recommended Overdose Treatment: General symptomatic and supportive measures should be used along with immediate gastric lavage. Respiration, pulse, and blood pressure should be monitored as in all cases of drug overdosage. No specific antidote is known to buspirone, and dialyzability of buspirone has not been determined.