Atypical Antipsychotics: Part II Adverse Effects, Drug Interactions, and Costs

Abstract

OBJECTIVE: To compare the adverse effects, drug interactions, and costs of conventional and atypical agents, and to provide a summary of therapeutic guidelines. Part I compared the pharmacology, pharmacokinetics, and efficacy of atypical and conventional agents. DATA SOURCES: Information was retrieved from a MEDLINE English-language literature search from June 1986 to June 1998 and by review of references. Indexing terms included atypical antipsychotics, neuroleptics, clozapine, risperidone, olanzapine, sertindole, quetiapine, and ziprasidone. STUDY SELECTION: Comparative studies were selected when possible; placebo-controlled studies were included when data were limited on newer atypical antipsychotics. DATA EXTRACTION: Emphasis was placed on properly designed clinical trials that assessed dosage, expanded efficacy, enhanced adverse effect profile, and cost. DATA SYNTHESIS: Significant adverse effects are agranulocytosis with clozapine, dose-dependent extrapyramidal side effects (EPS) with risperidone, and neuroleptic malignant syndrome with clozapine and risperidone. Clinically relevant drug interactions may occur with clozapine–lorazepam, clozapine–fluvoxamine, and sertindole– quinidine. Newer atypical agents have high acquisition costs but may reduce noncompliance and rehospitalization rates. CONCLUSIONS: Risperidone or olanzapine are recommended as first-line agents for schizophrenia due to accumulating controlled trials and clinical experience. Quetiapine should be considered with partial response or if EPS develop, and clozapine is an option with treatment-refractory patients. Atypical agents may contribute to a better quality of life, but conventional neuroleptics are the first choice for strictly cost considerations.