A Review and Bayesian Meta-Analysis of Clinical Efficacy and Adverse Effects of 4 Atypical Neuroleptic Drugs Compared With Haloperidol and Placebo
ABSTRACT The objective of the study was to examine the efficacy and the degree of adverse effects connected with atypical neuroleptic drugs and haloperidol by using a previously described Bayesian statistical method that includes both direct and indirect comparisons simultaneously.
The authors used the results of 30 double-blind, randomized studies including comparisons of 4 atypical neuroleptics and haloperidol, head-to-head or against placebo. We calculated the response ratios for drugs against placebo and thereafter the relative response ratios for one drug against another. With uniform priors, we calculated and ranked the posterior estimates of response ratios for antipsychotic effect, weight gain, and occurrence of extrapyramidal symptoms.
All second-generation neuroleptics analyzed are fairly effective with response ratios against placebo ranging between 1.55 (credibility interval, 1.36-1.76) and 1.99 (1.76-2.26), with clozapine being the most effective and aripiprazole the least effective among them. The risk of inducing weight gain is clearly very high for all 5 neuroleptic drugs compared with placebo with response ratios of 12.21 (10.22-15.05) for olanzapine and 11.28 (6.89-17.77) for clozapine. There is a clear increased risk of extrapyramidal adverse effects for haloperidol compared with placebo as the response ratio is 2.33 (2.03-2.49). The other drugs all have considerably less risk of extrapyramidal adverse effects.
The 4 second-generation neuroleptics included in our meta-analysis show only small differences in overall efficacy, with clozapine being the most effective and aripiprazole the least effective among them. When the risk of adverse effects is analyzed, olanzapine and clozapine are afflicted with the highest risk of inducing weight gain and haloperidol with extrapyramidal symptoms. Even aripiprazole and risperidone, however, induce considerable weight gain compared with placebo but may be acceptable alternatives when tailoring drug treatment to the individual patient.
SourceAvailable from: Gabriel de Erausquin[Show abstract] [Hide abstract]
ABSTRACT: We tested the hypothesis that loss of substantia nigra neurons in subjects at risk of schizophrenia (1), as reflected by midbrain hyperechogenicity (2) and parkinsonian motor impairment (3), is asymmetric and influenced by sex. We evaluated 62 subjects with never-treated chronic schizophrenia, 80 of their adult, unaffected first degree relatives and 62 healthy controls (matched by sex and age to the cases), part of an Andean population of Northern Argentina. Parkinsonism was scored blindly using UPDRS-3 (Unified Parkinson's Disease Rating Scale) on videotaped exams by 2 independent raters. Transcranial ultrasound was performed by an expert sonographist blind to subject condition with a 2.5MHz transducer through a temporal bone window. Quantification of echogenic area was carried out on saved images by a different evaluator. We found a significant difference in parkinsonian motor impairment between patients, their relatives as well as controls. All three groups showed worse parkinsonism on the left side than the right, corresponding with increased echogenicity on the right substantia nigra compared with the left. Females had significantly more right echogenicity than males, and patients and unaffected relatives were significantly more echogenic than controls on that side. On the left, only female patients had significant echogenicity. Our data supports the notion that unaffected relatives of schizophrenic subjects have increased parkinsonism and concomitant brainstem abnormalities which may represent a vulnerability to the disease. Both motor and brainstem abnormalities are asymmetric and influenced by sex. Copyright © 2015 Elsevier B.V. All rights reserved.Schizophrenia Research 02/2015; DOI:10.1016/j.schres.2015.01.035 · 4.43 Impact Factor
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ABSTRACT: Second-generation antipsychotics have been repeatedly shown to be superior to placebo. However, the comparative efficacy among these drugs has not been systematically evaluated. In this study, we used Mixed Treatment Comparison (MTC) procedures to elucidate the comparative efficacy and tolerability of second-generation antipsychotics. Seven antipsychotics were selected based on the availability of the relevant data. Data were gathered from a series of review article published by the Cochrane Collaboration. Six outcome measures were analyzed: 1) percentage of no clinically important response as defined by the original authors, 2) PANSS total score change from baseline to endpoint, 3) percentage of akathisia, 4) percentage of antiparkinson medication use, 5) percentage of total body weight increase more than 7%, and 6) percentage of drop-out due to any reasons. All the second-generation antipsychotics included in this study showed fairly similar efficacy but widely different tolerability. In terms of efficacy, amisulpride, clozapine and olanzapine were ranked higher than aripiprazole, quetiapine and ziprasidone. Clozapine and olanzapine were superior in terms of akathisia and extrapyramidal symptom risk, but, far more prone to induce clinically important weight gain. Using MTC methodology, we could line up the second generation antipsychotics according to their hierarchical superiority in terms of efficacy and tolerability. Though the wide overlap among the confidence intervals and the inconsistency between the direct and indirect comparison results may limit the validity of these results, it may still allow the important insights into the relative merits of the available drugs.Psychiatry investigation 01/2015; 12(1):46-54. DOI:10.4306/pi.2015.12.1.46 · 1.15 Impact Factor
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ABSTRACT: Several methods for imputing the number of responders from summary continuous outcome data in randomized controlled trials exist. A method by Furukawa and others was used in the quite common case that only such summary continuous outcome measures, but not the actual numbers of responders, are reported in order to estimate response rates (probabilities) for different treatments and response ratios between treatments in such trials. The authors give some empirical justification, but encourage search for theoretical support and further empirical exploration. In particular, a problem that needs to be addressed is that randomness in baseline score is not taken into consideration. This will be done in the present paper. Assuming a binormal model for the data, we compare theoretically the true response rate for a single treatment arm to the theoretical response rate underlying two versions of the suggested imputation method. We also assess the performance of the method numerically for some choices of model parameters. We show that the method works satisfactorily in some cases, but can be seriously biased in others. Moreover, assessing the uncertainty of the estimates is problematic. We suggest an alternative Bayesian estimation procedure, based directly on the normal model, which avoids these problems and provides more precise estimates when applied to simulated data sets.Methodology And Computing In Applied Probability 01/2014; DOI:10.1007/s11009-014-9408-5 · 0.78 Impact Factor