Receptor effects and therapeutic spectrum of mirtazapine

Abstract

Mirtazapine is a dual-acting antidepressant that acts on both noradrenergic and serotonergic neurotransmission through alpha-2 receptor antagonism. It has a unique pharmacological profile among other antidepressants. Antidepressant effect appears in moderate to severe depression. It also shows anxiolytic effect. Antagonism to 5-HT3-receptors provides indications for prescribing the antidepressant for anxiety and sleep disorders. Antagonism to 5-HT3-receptors determines the antiemetic effect and suppression of excessive release of mesolimbic dopamine. The toxic effects are significantly less pronounced if compared to tricyclic antidepressants. There are no drug interactions and serotonin syndrome. Therapy with mirtazapine should be started with the dose of 15 mg per day followed by the increase to therapeutic dose. The dose exceeding 30–45 mg per day does not add a significant therapeutic effect. The antidepressant should be administered in the evening, taking into account sedative and hypnotic effect in the initial period of therapy. Mirtazapine can be given as monotherapy or in combination with other medicines. The most effective combination for treatment of resistant depression appears to be the combination of mirtazapine and venlafaxine. Mirtazapine can be effectively used in treatment of functional disorders of the gastrointestinal tract, accompanied by nausea, vomiting, pain and diarrhea. It reduces the risk of complications and death from COVID-19.