Tandospirone 112457-95-1

Pharmacology

Tandospirone acts as a potent and selective 5-HT_1A receptor partial agonist, with a K_i affinity value of 27 ± 5 nM and approximately 55-85% intrinsic activity. It has weak but clinically negligible affinity for the 5-HT_2A (1,300 ± 200), 5-HT_2C (2,600 ± 60), α₁-adrenergic (1,600 ± 80), α₂-adrenergic (1,900 ± 400), D₁ (41,000 ± 10,000), and D₂ (1,700 ± 300) receptors, and is essentially inactive at the 5-HT_1B, 5-HT_1D, β-adrenergic, and muscarinic acetylcholine receptors, serotonin transporter (SERT), and benzodiazepine (BDZ) allosteric site of the GABA_A receptor (all of which are > 100,000). There is evidence of tandospirone having low but significant antagonistic activity at the α₂-adrenergic receptor through its active metabolite 1-(2-pyrimidinyl)piperazine (1-PP), however.

Dosage

Tandospirone is typically used at a dose of 30 mg/daily taken in divided doses of 10 mg three times per day due to its short half-life. Though originally considered a relatively weak anxiolytic agent, a clinical study found that doubling the dose to 60 mg/daily resulted in a "remarkable anxiolytic effect with an early onset of action, and without significant adverse effects", as well as "excellent anxiolytic efficacy that is comparable to that of the benzodiazepines".

Side effects

Side effects of tandospirone and other 5-HT_1A partial agonists are relatively mild and may include nausea, diarrhea, headache, dizziness, and restlessness.