The study was conducted by researchers at the departments of Psychiatry at Georgia Regents University and Columbia University who randomized 311 adults with schizophrenia or schizoaffective disorder to receive monthly injections of either haloperidol decanoate (the older long-acting antipsychotic) or paliperidone palmitate (the second-generation long-acting antipsychotic; trade name Invega Sustenna) for 24 months. Rates for efficacy failure were determined by a need for psychiatric hospitalization or crisis stabilization and a substantial increase in frequency of outpatient visits. Patients were also monitored for adverse health events.
The analysis revealed no significant difference in the rate of efficacy failure among the two treatment groups. However, participants taking paliperidone gained weight progressively over time, while those taking haloperidol lost weight. Treatment with paliperidone was associated with elevated serum levels of the prolactin hormone, whereas haloperidol was associated with more akathisia.
In an accompanying editorial, JAMA Associate Editor Donald Goff, M.D., said, “The results from [this] trial suggest that drug selection should be based on anticipated adverse effects rather than efficacy.” Goff, who is the vice chair for psychiatry research at New York University Langone Medical Center, emphasized that additional data are needed to investigate how long-term exposure to extended-release drugs and a wider range of antipsychotics contribute to adverse effects. “Not only is the compilation of reliable data about these drugs essential, so also is the clear communication of this information to patients as part of the shared decision-making process,” Goff concluded.
To read more about extended-release antipsychotics, see Psychiatric News article, "Company Describes Encouraging Outcomes of Schizophrenia Drug Trials." For more about medications to treat psychotic disorders, see The Evidence-Based Guide to Antipsychotic Medications from American Psychiatric Publishing.