Management of nonresponse and intolerance: switching strategies.

Approximately 29% to 46% of depressed patients show only partial or no response to treatment with antidepressants, with intolerance a frequent cause of treatment failure or discontinuation. Clinicians frequently switch to other antidepressants patients who have failed to tolerate or to respond to antidepressant treatment. The switching strategy involves substitution of another agent for the agent that has either caused intolerable side effects or has failed to induce a response. Fredman and colleagues have recently surveyed 402 psychiatrists from various parts of the country and asked them what steps they would take for patients who fail to respond to 8 weeks or more of an adequate dose of a selective serotonin reuptake inhibitor (SSRI). Interestingly, switching to a non-SSRI agent was the most popular choice indicated by psychiatrists (44% of respondents), with dual-acting agents and bupropion being the next most commonly chosen agents. Even though there are no controlled trials of switching strategies in the literature to date, clinicians often choose this course of action. This article will review some of the currently available studies on switching strategies.