Major Depressive Disorder
Mirtazapine is used in the treatment of major depressive disorder. Efficacy of mirtazapine for the management of major depression has been established by controlled studies of 6 weeks' duration in outpatient settings. Results of these studies indicate that the antidepressant effect of mirtazapine (5-35 mg daily) is greater than placebo and comparable to that of tricyclic antidepressants (e.g., amitriptyline [40-280 mg daily]). In these studies, no age- or gender-related differences in efficacy were noted. The manufacturer states that the efficacy of mirtazapine for long-term use (i.e., exceeding 6 weeks) has not been established by controlled studies and that the drug's antidepressant efficacy in hospital settings has not been adequately studied to date. However, acute depressive episodes generally require several months or longer of sustained antidepressant therapy.
(See Dosage and Administration: Dosage.)If mirtazapine is used for extended periods, the need for continued therapy should be reassessed periodically. For further information on treatment of major depressive disorder and considerations in choosing the most appropriate antidepressant for a particular patient, including considerations related to patient tolerance, patient age, and cardiovascular, sedative, and suicidal risks, .
Since hypomanic or manic attacks have been reported rarely in patients receiving mirtazapine, the drug should be used with caution in patients with a history of hypomanic or manic attacks.
Individuals with phenylketonuria (i.e., homozygous genetic deficiency of phenylalanine hydroxylase) and other individuals who must restrict their intake of phenylalanine should be warned that mirtazapine orally disintegrating tablets (Remeron SolTab) contain aspartame (NutraSweet), which is metabolized in the GI tract to provide about 2.6, 5.2, or 7.8 mg of phenylalanine following oral administration of a 15-, 30-, or 45-mg tablet, respectively, of mirtazapine.