To Abruptly Cross Over or Not: That Is the Question in SSRI Conversion

Patients are often required to “cross over” between selective serotonin reuptake inhibitors (SSRIs) because of cost savings or a lack of the agent’s effectiveness. Pharmacokinetics, serotonin syndrome, and withdrawal symptoms must be considered when therapy is changed. This review analyzes the data available regarding changing from one SSRI to another; however, the findings are inconclusive in terms of the advisability of safely and abruptly switching from one SSRI to another. Therefore, we recommend evaluating the pharmacokinetic profile of the SSRI agents when a switch is being considered. SSRIs with a longer halflife may cause symptoms of serotonin syndrome if patients are switched, whereas using agents with a shorter half-life may result in withdrawal symptoms. Patients should be aware of the possible excessive serotonin-related symptoms that can occur within the first few days to weeks after a switch.