[Trazodon--the antidepressant: mechanism of action and its position in the treatment of depression].

The pharmacological properties and possible clinical use of trazodon in the treatment of depression are presented. Trazodon is the only antidepressant from the SARI (Serotonin Antagonists and Reuptake Inhibitors) group available in Poland. It has a wide pharmacodynamic profile (being an antagonist of 5-HT2A and 5-HT2C serotoninergic receptors, alpha1 and alpha2 adrenergic receptors as well as H1 histaminergic receptors, and in higher doses it blocks the SERT serotonine transporter) which explains its wide therapeutic spectrum ranging from symptomatic treatment, through the potentialization of other drugs activity, all the way to monotherapy of depressive syndromes. An especially complex action on the serotoninergic system results in the lack of unwanted side-effects during treatment with trazodon (e.g. sexual dysfunction, significant body weight gain), which may be present during the treatment with other drugs (selective serotonin reuptake inhibitors). It is metabolised by the CYP450 isoenzyme: mainly the 2D6 and 3A4. This requires its dose to be adjusted when administered simultaneously with other drugs influencing the activity of those isoenzymes. Trazodon CR is an orally administered controlled release form, which simplifies its dosage and reduces the risk of adverse effects. Usually doses of 75 to 600mg daily are used; in the elderly those doses should be lower. Trazodon turned out to be effective in the treatment of various depressive syndromes, amongst them depression with insomnia, with anxiety and unrest, as well as depression in the elderly. In the recommended dose spectrum, trazodon is well tolerated. Unwanted adverse effects of the drug appear rarely and they are: somnolence, dizziness, gastrointestinal dysfunctions, and dry mouth.