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 BRAND NAMES
 MECHANISM OF ACTION
Buspirone reduces anxiety but, unlike classical anxiolytics (benzodiazepines), it lacks the anticonvulsant, sedative, and muscle-relaxant effects (it has no significant affinity for benzodiazepine receptors and does not affect GABA binding).
The basis for Buspirone clinical action is not known, but action at both dopamine D2 and serotonin 5-HT1A receptors has been suggested; In fact in vitro preclinical studies have shown that buspirone has a high affinity for serotonin (5-HT1A receptor) receptors and moderate affinity for brain D2-dopamine receptors. The ability of buspirone to block presynaptic nigrostriatal D2 dopamine (DA) autoreceptors in lower doses appears to result in increased dopamine synthesis and release
Buspirone is 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 recommended initial dose is 15 mg daily (7.5 mg twice a day). 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, consequently, patients should take buspirone in a consistent manner with regard to the timing of dosing; either always with or always without food.
Hypersensitivity to buspirone
- Buspirone does not exhibit cross-tolerance with benzodiazepines and other common sedative/hypnotic drugs, it will not block the withdrawal syndrome often seen with cessation of therapy with these drugs. Therefore, before starting therapy with Buspirone, it is advisable to withdraw patients gradually, especially patients who have been using a CNS-depressant drug chronically, from their prior treatment.
- Buspirone should not be used concomitantly with an monoamine oxidase inhibitor (MAOI) because of a risck of elevated blood pressure.
- Avoid alcohol
- Buspirone is metabolized by CYP3A4:
- Inhibitors of CYP3A4 like Diltiazem,Verapamil, Erythromycin, Clarithromycin, Itraconazole, Ketoconazole, Nefazodone, Ritonavir and Grapefruit Juice increase plasma concentration of buspirone.
- Inducers of CYP3A4 like Rifampin, Dexamethasone or certain anticonvulsants (phenytoin, phenobarbital, carbamazepine), may increase the rate of buspirone metabolism. The dosage of buspirone may need adjusting to maintain anxiolytic effect.
 PREGNANCY AND LACTATION
- Pregnancy Category B (US). Buspirone should be used during pregnancy only if clearly needed.
- Nursing Mothers: The extent of the excretion in human milk of buspirone or its metabolites is not known. In rats, however, buspirone and its metabolites are excreted in milk. Buspirone administration to nursing women should be avoided if clinically possible
 SIDE EFFECTS
The more commonly observed adverse events include dizziness, nausea, headache, nervousness, lightheadedness, and excitement.