Subsequent meta-analyses have generally confirmed these results 16 and have helped to provide a clearer picture of the comparative effectiveness of the two classes of antipsychotics. 8 Recent findings from CutLASS 1 (Cost Utility of the Latest Antipsychotic Drugs in Schizophrenia Study) 12,13 and the CATIE (Clinical Antipsychotic Trials of Intervention Effectiveness) study 14,15 found few differences in the effectiveness of SGAs and FGAs in patients with nonrefractory Schizophrenia. 8,11 Trials in which SGAs have been evaluated are criticized for their 1) inclusion of patients with positive and negative symptoms, making it unclear whether a drug is having direct effects, indirect effects, or both, on primary negative symptoms, 11 and 2) derivation of data on negative symptoms from short-term trials that focus on patients selected on the basis of positive symptoms (or, for longer-term trials, on the basis of clinical stability). There is debate surrounding the efficacy of SGAs on negative symptoms, with several published reports indicating that there is no clear advantage over FGAs. The long-term consequences of SGAs remain largely unknown. 9 SGAs have also been associated with metabolic side effects, 9 but it is unclear whether these are secondary to, independent of, or causative of weight gain. As a class, they have a more favorable profile in terms of extrapyramidal side effects and tardive dyskinesia, but produce other side effects, including sedation, hypotension, weight gain, and sexual dysfunction. Although SGAs were developed to improve on the shortcomings of FGAs, they also have significant limitations in terms of side effects. When compared to FGAs, SGAs have shown greater benefits in many outcome domains, 9 and newer medications are replacing the conventional antipsychotics as treatments of choice. A series of SGA compounds have been developed (i.e., risperidone, olanzapine, quetiapine). The search for antipsychotic medications to manage both the positive and negative symptoms of Schizophrenia led to the reestablishment of clozapine in the early 1990s and signaled a new generation of antipsychotic drugs (termed “atypical” or second-generation antipsychotics ). 7 Such symptoms particularly play a critical role in producing the severe social and vocational disabilities experienced by many patients with Schizophrenia. 5,6 While these antipsychotics are effective against the positive symptoms of Schizophrenia, they have been considered to be ineffective in treating negative symptoms. 4 This mechanism, however, leads to a variety of extrapyramidal side effects (e.g., tremor, slurred speech, akathisia, dystonia), some of which appear after long-term exposure (e.g., tardive dyskinesia). 3Ĭonventional antipsychotics (termed typical or first-generation antipsychotics (i.e., haloperidol, chlorpromazine)), act on the dopaminergic system by blocking the dopamine type 2 (D2) receptors. The American Psychiatric Association (APA) currently recommends that selection of an antipsychotic should be based on a patient’s previous responses to the drug and its side effect profile. 2 Antipsychotics represent the first-line treatment for patients with Schizophrenia and have been the mainstay treatment since the 1950s. Onset of symptoms typically occurs in late adolescence or young adulthood, with approximately 0.4 to 0.6 percent of the population affected worldwide. 1 Symptoms include positive (i.e., delusions, hallucinations) and negative (i.e., passive/apathetic social withdrawal, blunted affect) symptoms and general psychopathology (i.e., preoccupation, lack of insight, motor retardation). Schizophrenia is a heterogeneous syndrome that includes disturbances in language, perception, cognition, social relatedness, and volition. Background and Objectives for the Systematic Review Schizophrenia and Related Psychoses
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |