NORBALCopy

• DRUGBANK - Buspirone
• indication:

  For the management of anxiety disorders or the short-term relief of the symptoms of anxiety, and also as an augmention of SSRI-treatment against depression.

• pharmacology:

• mechanism:

  Buspirone binds to 5-HT type 1A serotonin receptors on presynaptic neurons in the dorsal raphe and on postsynaptic neurons in the hippocampus, thus inhibiting the firing rate of 5-HT-containing neurons in the dorsal raphe. Buspirone also binds at dopamine type 2 (DA2) receptors, blocking presynaptic dopamine receptors. Buspirone increases firing in the locus ceruleus, an area of brain where norepinephrine cell bodies are found in high concentration. The net result of buspirone actions is that serotonergic activity is suppressed while noradrenergic and dopaminergic cell firing is enhanced.

• toxicity:

  Oral, rat LD<sub>50</sub> = 136 mg/kg. Symptoms of overdose include dizziness, drowsiness, nausea or vomiting, severe stomach upset, and unusually small pupils.

• absorprion:

  Rapidly absorbed in man. Bioavailability is low and variable (approximately 5%) due to extensive first pass metabolism.

• halflife:

  2-3 hours (although the action of a single dose is much longer than the short halflife indicates).

• roouteelimination:

  In a single-dose study using 14C-labeled buspirone, 29% to 63% of the dose was excreted in the urine within 24 hours, primarily as metabolites; fecal excretion accounted for 18% to 38% of the dose.

• volumedistribution:

• clearance: