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Member Research & Reports

Member Research & Reports

UNC: Little Difference Found in Effectiveness of Two Antipsychotic Drugs Used for Treatment of Schizophrenia

A University of North Carolina Gillings School of Global Public Health researcher and his colleagues have found little difference in the efficacy and side effects of two widely prescribed antipsychotic drugs, one of which came into use within the last five years.

Dr. Robert M. Hamer, research professor of biostatistics at UNC Gillings School of Global Public Health and of psychiatry in the UNC School of Medicine, worked with a team of researchers, including lead author Dr. Joseph P. McEvoy, of the psychiatry and health behavior department at Georgia Regents University, and senior author Dr. T. Scott Stroup, of Columbia University College of Physicians and Surgeons’ psychiatry department and the New York State Psychiatric Institute.

The researchers compared the effectiveness of a second-generation, long-acting injectable version of paliperidone palmitrate (PP), which was introduced in 2009, with an older but similar antipsychotic, haloperidol decanoate (HD). The study found that among adults with schizophrenia, treatment with PP did not result in a statistically significant difference in efficacy failure. Their findings were published in the May 21 issue of the Journal of American Medical Association.

Efficacy failure is defined as a psychiatric hospitalization, a need for crisis stabilization or a substantial increase in the number of outpatient visits, among other results. Long-acting injectable antipsychotic medications are prescribed to help keep patients on their medication and reduce relapse in people diagnosed with a schizophrenia-spectrum disorder. Long-acting injectable versions of HD and older antipsychotic medications have been available for decades.

Trials and analyses of newer antipsychotic drugs such as PP have raised questions about the drugs’ safety and effectiveness. Their use has been linked to side effects that include weight gain, elevated cholesterol levels, and susceptibility to diabetes mellitus.

While drugs such as HD can have similar side effects, PP has some logistical advantages. The latter drug can be administered monthly and does not require costly storage or reconstitution measures.