A Candidate Gene Study of Tardive Dyskinesia in the CATIE Schizophrenia Trial
ABSTRACT Tardive dyskinesia (TD) is a movement disorder characterized by involuntary oro-facial, limb, and truncal movements. As a genetic basis for inter-individual variation is assumed, there have been a sizeable number of candidate gene studies. All subjects met diagnostic criteria for schizophrenia and were randomized to receive antipsychotic medications as participants in the Clinical Antipsychotic Trials of Intervention Effectiveness project (CATIE). TD was assessed via the Abnormal Involuntary Movement Scale at regular intervals. Probable TD was defined as meeting Schooler-Kane criteria at any scheduled CATIE visit (207/710 subjects, 29.2%). A total of 128 candidate genes were studied in 710 subjects-2,580 SNPs in 118 candidate genes selected from the literature (e.g., dopamine, serotonin, glutamate, and GABA pathways) and composite genotypes for 10 drug-metabolizing enzymes. No single marker or haplotype association reached statistical significance after adjustment for multiple comparisons. Thus, we found no support for either novel or prior associations from the literature.
Article: Perphenazine for schizophrenia.[Show abstract] [Hide abstract]
ABSTRACT: Perphenazine is an old phenothiazine antipsychotic with a potency similar to haloperidol. It has been used for many years and is popular in the northern European countries and Japan. To examine the clinical effects and safety of perphenazine for those with schizophrenia and schizophrenia-like psychoses. We updated our original search using the Cochrane Schizophrenia Group's register (September 2013), references of all included studies and contacted pharmaceutical companies and authors of included studies in order to identify further trials. We included all randomised controlled trials that compared perphenazine with other treatments for people with schizophrenia and/or schizophrenia-like psychoses. We excluded trials of depot formulations of perphenazine. Two review authors independently inspected citations and, where possible, abstracts. We ordered papers, inspected and quality assessed them. We extracted data, again working independently. If loss to follow-up was greater than 50% we considered results as 'prone to bias'. For dichotomous data, we calculated risk ratios (RR) and for continuous data we calculated mean differences (MD), both with the 95% confidence intervals (CI). We assessed quality of data using the GRADE (Grading of Recommendations Assessment, Development and Evaluationtool) and assessed risk of bias for included studies. Thirty-one studies fulfilled the inclusion criteria, with a total of 4662 participants (of which 4522 were receiving the drugs relevant to our comparison) and presented data that could be used for at least one comparison. The trial centres were located in Europe (especially Scandinavia), Japan and Northern America.When comparing perphenazine with placebo, for our primary outcome of clinical response, results favoured perphenazine with significantly more people receiving placebo rated as either 'no better or deterioration' for global state than people receiving perphenazine (1 RCT, n = 61 RR 0.32 CI 0.13 to 0.78, very low quality evidence). More people receiving placebo relapsed, although not a statistically significant number (1 RCT, n = 48, RR 0.14 CI 0.02 to 1.07, very low quality evidence). Death was not reported in the perphenazine versus placebo comparison. Experiences of dystonia were equivocal between groups (1 RCT, n = 48, RR 1.00 CI 0.07 to 15.08, very low quality evidence); other outcomes not reported in this comparison include serious adverse events, economic outcomes, and service use and hospitalisation.For the comparison of perphenazine versus any other antipsychotic drugs, no real differences in effect between the drugs were found. There was no significant difference between groups for those considered 'no better or deterioration' (17 RCTs, n = 1879, RR 1.04 CI 0.91 to 1.17, very low quality evidence). For mental state outcome of 'no effect' of the study drug, there was again no significant difference between groups (4 RCTs, n = 383, RR 1.24 CI 0.61 to 2.52, very low quality evidence). Death was not reported in any of the included studies. There was no significant difference in rates of dystonia with perphenazine versus any other antipsychotic drugs (4 RCTs, n = 416, RR 1.36 CI 0.23 to 8.16, very low quality evidence), nor was there a significant difference between groups for serious adverse events (2 RCTs, n = 1760, RR 0.98 CI 0.68 to 1.41, very low quality evidence). Although perphenazine has been used in randomised trials for more than 50 years, incomplete reporting and the variety of comparators used make it impossible to draw clear conclusions. All data for the main outcomes in this review were of very low quality evidence. At best we can say that perphenazine showed similar effects and adverse events as several of the other antipsychotic drugs. Since perphenazine is a relatively inexpensive and frequently used compound, further trials are justified to clarify the properties of this classical antipsychotic drug.Cochrane database of systematic reviews (Online) 03/2015; 3:CD003443. DOI:10.1002/14651858.CD003443.pub3 · 5.94 Impact Factor
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ABSTRACT: PURPOSE OF REVIEW: Antipsychotic drugs are effective in alleviating a variety of symptoms and are medication of first choice in schizophrenia. However, a substantial interindividual variability in side effects often requires a lengthy 'trial-and-error' approach until the right medication is found for the right patient. Genetic factors have long been hypothesized to be involved and identification of related gene variants could be used to predict and tailor drug treatment. RECENT FINDINGS: This review highlighting the most recent genetic findings was conducted on the two most common and most well-studied side effects: antipsychotic-induced weight gain and tardive dyskinesia. SUMMARY: Regarding weight gain, most promising and most consistent findings were obtained in the serotonergic system (HTR2C) and with hypothalamic leptin-melanocortin genes, in particular with one variant close to the melanocortin-4-receptor (MC4R) gene. With respect to tardive dyskinesia, most interesting findings were generally obtained in genes related to the dopaminergic system (dopamine receptors D2 and D3), and more recently with glutamatergic system genes. Overall, genetic studies have been successful in identifying strong findings, in particular for antipsychotic-induced weight gain and to some extent for tardive dyskinesia. Apart from the need for replication studies in larger and well-characterized samples, the next challenge will be to create predictive algorithms that can be used for clinical practice.Current opinion in psychiatry 03/2013; 26(2):144-150. DOI:10.1097/YCO.0b013e32835dc9da · 3.55 Impact Factor
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ABSTRACT: Despite accumulating evidence pointing to a genetic basis for tardive dyskinesia, results to date have been inconsistent owing to limited statistical power and limitations in molecular genetic methodology. A Medline, EMBASE and PsychINFO search for literature published between 1976 and June 2007 was performed, yielding 20 studies from which data were extracted for calculation of pooled estimates using meta-analytic techniques. Evidence from pooled data for genetic association with tardive dyskinesia (TD) showed (1) in COMT(val158met), using Val-Val homozygotes as reference category, a protective effect for Val-Met heterozygotes (OR=0.63, 95% CI: 0.46-0.86, P=0.004) and Met carriers (OR=0.66, 95% CI: 0.49-0.88, P=0.005); (2) in Taq1A in DRD2, using the A1 variant as reference category, a risk-increasing effect for the A2 variant (OR=1.30, 95% CI: 1.03-1.65, P=0.026), and A2-A2 homozygotes using A1-A1 as reference category (OR=1.80, 95% CI: 1.03-3.15, P=0.037); (3) in MnSOD Ala-9Val, using Ala-Ala homozygotes as reference category, a protective effect for Ala-Val (OR=0.37, 95% CI: 0.17-0.79, P=0.009) and for Val carriers (OR=0.49, 95% CI: 0.24-1.00, P=0.047). These analyses suggest multiple genetic influences on TD, indicative of pharmacogenetic interactions. Although associations are small, the effects underlying them may be subject to interactions with other loci that, when identified, may have acceptable predictive power. Future genetic research will take advantage of new genomic knowledge. Molecular Psychiatry (2008) 13, 544-556; doi:10.1038/sj.mp.4002142; published online 8 January 2008.Molecular Psychiatry 06/2008; 13(5):544-56. DOI:10.1038/sj.mp.4002142 · 15.15 Impact Factor