Switching to Imipramine Versus Add-on Mirtazapine in Venlafaxine-Resistant Major Depression: A 10-Week Randomized...

Newer-generation antidepressants used in monotherapy or in combination with other newer-generation antidepressants or other psychotropic drugs are usually preferred as first- or second-step treatment options in resistant depression. According to our clinical experience, tricyclic antidepressants still are one of our preferred first choices in treatment-resistant moderate to severe unipolar major depressive episodes.

This 10-week open-design randomized study assessed the effectiveness of switching to imipramine (adjusted to plasma levels) compared with add-on mirtazapine (30 mg/d) for treatment of moderate to severe unipolar major depressive episodes after a 10-week unsuccessful venlafaxine regimen (225-300 mg/d). Efficacy analyses examined the change in depressive symptoms severity from baseline visit to endpoint and the comparative remission rate between treatment subgroups.

The randomized sample consisted of 112 venlafaxine-resistant moderate to severe unipolar major depressed patients. Both the percentage of remitters (71.43% vs 39.28%) and the mean reduction of the Hamilton Depression Rating Scale score (76.94% vs 50.72%) were significantly larger in the imipramine subgroup.

Even though we should be cautious about generalizing these results to patients with a less severe unipolar major episodes, our study suggest that switching to imipramine is a very effective treatment option in unipolar major depressive episodes after an unsuccessful venlafaxine regimen.