Study: Expensive, Newer Antipsychotic Medication Is No better Than Cheaper, Older Drug for Treatment of Schizophrenia
Paliperidone and haloperidol have similar rates of efficacy failure
Among adults with schizophrenia or schizoaffective disorder, treatment with the newer, more costly antipsychotic agent paliperidone palmitate (Invega Sustenna, Janssen), compared with the older antipsychotic drug haloperidol decanoate (Haldol, Janssen), found no significant difference on a measure of effectiveness, according to a study in the May 21 issue of JAMA.
Long-acting injectable antipsychotic medications are prescribed to reduce nonadherence to drug therapy and relapse in people diagnosed with a schizophrenia-spectrum disorder. The relative effectiveness of long-acting injectable versions of second-generation and older antipsychotic medications has not been previously assessed, according to background information in the article.
Researchers at Georgia Regents University, Augusta, randomly assigned 311 patients with schizophrenia or schizoaffective disorder to receive monthly injections of haloperidol decanoate or paliperidone palmitate for up to 24 months. The investigators recorded the rates of efficacy failure (defined as a psychiatric hospitalization), the need for crisis stabilization, the increase in the frequency of outpatient visits, the clinician’s decision that an oral antipsychotic could not be discontinued within 8 weeks after starting a long-acting injectable antipsychotic, or the clinician’s decision to discontinue the assigned long-acting injectable because of an inadequate therapeutic benefit.
The authors found no significant difference in the rate of efficacy failure for patients in the paliperidone palmitate group compared with those in the haloperidol decanoate group (33.8% vs. 32.4%, respectively). The most common reasons for efficacy failure were psychiatric hospitalization and clinician discontinuation of study medication due to inadequate therapeutic effect. The authors noted that their findings do not rule out the possibility of a clinically meaningful advantage with paliperidone palmitate.
Regarding adverse effects, on average, participants taking paliperidone palmitate gained weight progressively over time, while those taking haloperidol decanoate lost weight. Treatment with paliperidone palmitate was associated with greater increases in serum prolactin, whereas haloperidol decanoate was associated with more akathisia.
“The results [of this study] are consistent with previous research that has not found large differences in the effectiveness of newer and older antipsychotic medications,” the authors concluded.
In an accompanying editorial, Donald C. Goff, MD, Associate Editor of JAMA, wrote: “Setting aside the substantial differences in cost between haloperidol decanoate and paliperidone palmitate [approximately $35 vs. $1,000, respectively, per injection], the results from [this] trial suggest that drug selection should be based on anticipated adverse effects rather than on efficacy.”