Tolerability of High-Dose Venlafaxine After Switch From Escitalopram in Nonresponding Patients With Major Depressive Disorder.

Background: Within a single depressive episode, most patients receive different antidepressants because of an inadequate response to the first-line antidepressant. A commonly used strategy is to switch from a selective serotonin reuptake inhibitor to a selective serotonin-norepinephrine reuptake inhibitor. However, little is known about the tolerability of this switch with consideration of dose and drug concentration in blood.