Antidepressant switching: If one does not work, switch to another
Switching from a tricyclic antidepressant (TCA) to a selective serotonin reuptake inhibitor (SSRI), or the other way around, following failure of or side-effects to the first antidepressant appears to be a viable strategy to achieve response among patients with major depressive disorder (MDD), a study has found.
The study included 811 adult patients with MDD treated with nortriptyline or escitalopram for up to 12 weeks. Of these, 72 switched from nortriptyline to escitalopram after a mean of 6.2 weeks and 36 from escitalopram to nortriptyline after a mean of 7.0 weeks. Reasons for switching included side-effects (n=12), nonresponse (n=34) or both (n=60), whereas no data regarding reason for switching were given in two patients.
Researchers followed the patients for 26 weeks after switching to measure response using the Montgomery–Åsberg Depression Rating scale (MADRS). They found that switching led to a marked reduction in MADRS scores, from a mean of 24.2 at baseline to 18.2 at the end of follow-up among escitalopram-to-nortriptyline switchers (β, −0.38, 95 percent CI, −0.51 to −0.25; p<0.001) and from 21.5 to 15.1 among nortriptyline-to-escitalopram switchers (β, −0.34, −0.41 to −0.26; p<0.001).
Frequently recorded adverse reactions to escitalopram were nausea and vomiting (15 percent) and sexual dysfunction (30 percent). Common adverse effects of nortriptyline included dry mouth (80 percent), orthostatic dizziness (32 percent), drowsiness (27 percent) and constipation (24 percent).
Individuals who switched from nortriptyline to escitalopram were predominantly women (71 percent vs 47 percent; p=0.013) and had a younger age at onset of depressive symptoms (29.5 vs 36.8 years; p=0.003).
The findings indicate that switching to an antidepressant with a different receptor profile in the case of side-effects or nonresponse, despite sufficient dose and treatment duration, may improve treatment response, researchers said.