Datapoints: Second-Generation Antipsychotic Medication Combinations for Schizophrenia

Combination pharmacotherapy for schizophrenia is reportedly increasingly common in the community ( 1 ). Yet efficacy of medication combinations for the treatment of schizophrenia and the frequency of such practices in different treatment settings remain largely unstudied. In addition, second-generation antipsychotics in combination pose an increased side-effect and risk burden at significant public and private cost.

In order to determine patterns of prescribed second-generation antipsychotic combinations, we calculated frequencies using administrative and prescription data for over 6,000 individuals served by a large public mental health system for one month in 2002. Individuals were over the age of 18 and had a schizophrenia spectrum disorder.

Seventy-six percent of individuals in the study (5,083 of 6,666 individuals) were given prescriptions for at least one second-generation antipsychotic medication. As shown in Figure 1 , of the individuals who received a second-generation antipsychotic, many also received at least one other medication.

Our study demonstrates how analysis of a large administrative database can improve knowledge of real-world psychopharmacological practices and enhance treatment improvement efforts. Despite the reported milder side-effect profile of second-generation antipsychotics, many patients received anticholinergic medications. This may reflect higher total dosages of antipsychotic medications, multiple antipsychotic medications, or overuse of anticholinergic medication ( 2 ). Other than for a brief period while a drug is being tapered, antipsychotic polypharmacy is inconsistent with current treatment guidelines, unsupported by rigorous research, and costly.

This administrative database did not allow verification of diagnoses with standardized instruments, and limited information about dosages and duration did not allow us to determine total dosage or whether polypharmacy was short or long term.

Subsequent steps should include further research to explore efficacy and risks of medication combinations for treatment of schizophrenia and other alternative strategies to polypharmacy.

Acknowledgments and disclosures

Dr. Eisen and Dr. Wells were co-principal investigators on a study funded by Eli Lilly and Company. The other authors report no competing interests.