Switching Antipsychotic Medications / 대한정신약물학회지

ABSTRACT

Switch to another newer antipsychotic is indicated when current treatment is insufficiently effective or is associated with drug related adverse events that impair quality of life. There are two main switching strategies. The first `clean method' is to discontinue the previous treatment and then to start the new one. The second, more preferable method is cross-tapering where the previous and the new antipsychotic treatment are overlapped. Abrupt switching is usually indicated when severe side effects are present, but it may produce withdrawal problems or higher risk of relapse. When overlapping the previous and new treatments in cross-tapering, the daily dose of the former is tapered down progressively (by approximately 30-50% every 3 to 7 days) and the latter is started and titrated up progressively to achieve a therapeutic response. In relation to the speed of cross-tapering, it is important to maintain adequate therapeutic level of overlapping drugs to avoid relapse or adverse events associated with subtherapeutic or too high level of overlapping drugs. Caution is advised in patients who have suffered recent relapse, a severe psychotic episode or who are being treated as outpatients. Anticholinergic medication, if needed, should be continued for 2-4 weeks after the switch has been made. Treatment should be individualized. At least three months of full-dose treatment is required for the decision of successful drug switch. Patient education and frequent monitoring is essential in switching medications. Switch from clozapine need more caution and clozapine should be tapered slowly for 2-6 weeks except in inevitable cases. In this review, the advantages of switching to a newer antipsychotic drug in the management of patients with schizophrenia have been demonstrated while successful switching strategies being presented.