Switching antipsychotic medications: general recommendations and switching to amisulpride.

As more and more novel antipsychotic agents are introduced, the need for practical guidelines on switching these medications is becoming increasingly important. Indications for a switch include situations where the patient or his family/caregiver requests a change in medication, where the patient cannot tolerate current treatment, where they have comorbid physical or psychiatric conditions or where they have achieved only a partial remission, are refractory to treatment or have relapsed. Cross-tapering is generally the most acceptable method of switching, although abrupt withdrawal may be necessary in some cases, such as when a patient develops a severe or acute reaction to their current treatment. Possible problems of switching include the risk of discontinuation reactions and the re-emergence of psychotic symptoms. The pharmacological profile of amisulpride means it has a relatively low potential for interactions with other drugs and may be started while discontinuing the previous antipsychotic. It should be started at the target dose for the patient's current symptoms. A retrospective questionnaire among 60 patients switching to amisulpride treatment was undertaken to identify the characteristics of patients switching antipsychotics and their reasons. Patients were switched from a variety of antipsychotic medications, both traditional (42% of patients) and atypical (58%). Most patients (87%) had at least two reasons for changing medication, with lack of efficacy, adverse events and treatment optimisation before reintegration being the most common. Contrary to recommendations, 89% of patients were switched abruptly between medications. A total of 62% of patients received amisulpride doses in the range 400-800 mg/day and most (72%) required no dose adjustment. The great majority of patients (87%) switched to amisulpride without problems.