Mirtazapine - A review of its use in major depression

Mirtazapine is a noradrenergic and specific serotonergic antidepressant (Na SSA) which has predominantly been evaluated in the: treatment of major depr ession. The drug had equivalent efficacy to tricyclic antidepressants and i t was at least as effective as trazodone in the majority of available short term trials in patients with moderate or severe depression, including thos e with baseline anxiety symptoms or sleep disturbance and the elderly, A co ntinuation study also showed that sustained remission rates were higher wit h mirtazapine than with amitriptyline and that the drugs had similar effica cy for the prevention of relapse. There is some evidence for a. faster onse t of action with mirtazapine than with the selective serotonin (5-hydroxytr yptamine: 5-HT) reuptake inhibitors (SSRIs), Mirtazapine was more effective than the SSRI fluoxetine at weeks 3 and 4 of therapy and it was also more effective than paroxetine and citalopram at weeks 1 and 2, respectively, in short term assessments (6 or 8 weeks), preliminary data suggest that the d rug may be effective as an augmentation or combination therapy in patients with refractory depression. Anticholinergic events and other events including tremor and dyspepsia are less common with mirtazapine than with tricyclic antidepressants. There was a greater tendency for SSRI-related adverse events with fluoxetine than wi th mirtazapine, but, overall, mirtazapine hail a similar tolerability profi le to the SSRIs, Increased appetite and bodyweight gain appear to be the on ly events that are reported more often with mirtazapine than with comparato r antidepressants. In vitro and in vivo data have suggested that mirtazapin e is unlikely to affect the metabolism of drugs metabolised by cytochrome P 450 (CYP)2D6. although few formal drug interaction data are available. Conclusions: Mirtazapine is effective and well tolerated for the treatment of patients with moderate to severe major depression. Further research is r equired to define the comparative efficacy of mirtazapine in specific patie nt groups, including the elderly and those with severe depression. Clarific ation of its efficacy as an augmentation therapy and in patients with refra ctory depression and its role in improving the efficacy and reducing the ex trapyramidal effects of antipsychotic drugs would also help to establish it s clinical value, The low potential for interaction with drugs that are met abolised by CYP2D6, including antipsychotics, tricyclic antidepressants and some SSRIs, may also make mirtazapine an important option for the treatmen t of major depression in patients who require polytherapy, Mirtazapine also appears to be useful in patients with depression who present with anxiety symptoms and sleep disturbance.