May 20, 2014. Recent clinical trials such as CATIE have raised doubts about the advantages of oral forms of second-generation antipsychotics over their earlier counterparts (see SRF related news report; SRF news report). Making the same comparison between the long-acting injectable forms of these drugs, developed to increase medication adherence, has been difficult because injectable forms of atypical antipsychotics have only been available for the last decade. The first randomized clinical trial comparing long-acting injectable forms of first- and second-generation antipsychotics, published May 20 in JAMA and led by T. Scott Stroup, Columbia University, New York, reports differences in side effect profiles, but not efficacy.
In the ACLAIMS (A Comparison of Long-Acting Medications for Schizophrenia) trial, first author Joseph McEvoy, Georgia Regents University, Augusta, and colleagues compared first-generation haloperidol decanoate to the newer paliperidone palmitate in 311 adults with schizophrenia or schizoaffective disorder judged to be at risk for relapse. Paliperidone is a metabolite of risperidone, and the injectable form is sold by Janssen Pharmaceutica under the trade names INVEGA SUSTENNA in the United States and Xeplion in countries in Europe and elsewhere.
Over a period of up to two years, the two drugs were nearly identical in terms of efficacy failure rates. Approximately one-third of patients in both groups were reported to have a psychiatric hospitalization, an increase in outpatient visits, or other clinical intervention. By contrast, side effect profiles between the two injectables did differ: Paliperidone palmitate was associated with more weight gain and higher serum prolactin levels, while haloperidol decanoate was associated with more akathisia, or inner restlessness.
In an editorial accompanying the article, Donald Goff, New York University, writes, "Setting aside the substantial differences in cost between haloperidol decanoate and paliperidone palmitate, the results from the ACLAIMS trial suggest that drug selection should be based on anticipated adverse effects rather than efficacy."—Allison A. Curley.
McEvoy JP, Byerly M, Hamer RM, Dominik R, Swartz MS, Rosenheck RA, Ray N, Lamberti JS, Buckley PF, Wilkins TM, Stroup TS. Effectiveness of paliperidone palmitate vs. haloperidol decanoate for maintenance treatment of schizophrenia. JAMA. 2014;311(19):1978-1986. Abstract