Daniel C. Javitt, MD, PhD
When treating patients with schizophrenia, the overarching goals are to alleviate acute symptoms, maximize quality of life and functioning, and maintain recovery from acute illness.1
Optimal treatment should involve an integrative approach that combines psychosocial, educational, and pharmacologic management. This article discusses the overall management of schizophrenia, including recommendations from practice guidelines, results of important clinical trials, factors involved in choosing an appropriate antipsychotic agent, and issues involved in managing drug side effects.Pharmacologic Treatment
Antipsychotic medications are the mainstay of schizophrenia drug treatment. All of the antipsychotics are thought to work, at least in part, through actions on the dopamine type 2 (D2) receptors, and these agents have traditionally been categorized into first-generation or second-generation groupings.2 The first-generation antipsychotics (FGAs), previously referred to as “typical” antipsychotics, are thought to work almost exclusively through D2 antagonism. It has been demonstrated that 65% to 70% occupancy at D2 receptors is associated with an antipsychotic response, whereas 80% occupancy and higher is associated with extrapyramidal symptoms (EPSs), such as dystonia, psuedoparkinsonism, akathisia, and tardive dyskinesia.2 Due to their strong affinity for the D2 receptor, FGAs have a significant risk of side effects even at the lowest possible therapeutic dose. Haloperidol and fluphenazine are the FGAs with the most potent affinity for the D2 receptor. The FGAs that are associated with somewhat lower rates of EPSs are those with less potency at the D2 receptor and more anticholinergic receptor affinity, such as chlorpromazine and thioridazine (Table 13,4
). Although these differences in receptor affinities lower the risk of EPSs, they also increase the risk of sedation and secondary cognitive impairment.
The second-generation antipsychotics (SGAs), also termed “atypical” antipsychotics, have more potent antagonism at serotonin type-2A (5-HT2A) receptors, and reduced binding affinity for D2 receptors, which is thought to reduce (but not eliminate) the risk of EPSs and prolactin elevation.2 However, many SGAs have turned out to have a high potential for metabolic adverse effects, such as weight gain, lipid abnormalities, glucose abnormalities, and even diabetes; although the exact metabolic risk profile varies from agent to agent (Table 23,5-7
).Place of Antipsychotics in Schizophrenia Therapy
One of the major focuses of schizophrenia research over the past decade has been to examine the relative treatment benefits of each generation of antipsychotics. Results from several landmark clinical trials have been published during this time, the largest of which was funded by the National Institute of Mental Health. This trial, one of a series referred to as the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE), compared rates of all-cause discontinuation in 1432 patients treated with either an SGA (ie, olanzapine, quetiapine, risperidone, or ziprasidone) or the FGA perphenazine.
Olanzapine showed a longer time to discontinuation for any reason compared with the other antipsychotics (9.2 months for olanzapine vs 3.5-5.6 months for the others); however, this difference was not significant when compared with perphenazine alone. Perphenazine showed effectiveness comparable to that of the other SGAs used in the study. Patients with schizophrenia treated with olanzapine experienced higher rates of clinically significant weight gain (≥7% of body weight) compared with the other antipsychotics (30% with olanzapine vs 7% with ziprasidone, 12% with perphenazine, 14% with risperidone, and 16% with quetiapine; P
<.001) and had greater increases in glycated hemoglobin (A1C), total cholesterol, and triglycerides. Other adverse effects seen were generally consistent with those observed in clinical practice. Risperidone was associated with the greatest increase in prolactin (P
<.001) and perphenazine had the highest rate of discontinuation due to EPSs (P
= .002), although there were no significant differences in the rates of EPSs between the different treatment groups.8 Another trial with a similar goal to CATIE was the European Cost Utility of the Latest Antipsychotic Drugs in Schizophrenia Study (CUtLASS 1). This trial examined improvement in quality of life as measured by the Quality of Life Scale (QLS) in 185 patients who were treated over a period of 1 year with either an FGA or an SGA. No significant difference was observed in the primary outcome (QLS) in either treatment arm, nor in any of the secondary outcomes, including symptom improvement, treatment adherence, attitudes toward medication, or extrapyramidal side effects.9
Similar studies were completed in patients with schizophrenia who were experiencing their first episode of psychosis (FEP). The European First Episode Schizophrenia Trial (EUFEST) examined 498 such patients over 1 year of randomized treatment with haloperidol, amisulpride (an SGA not approved in the United States), olanzapine, quetiapine, or ziprasidone. More patients discontinued haloperidol for any reason than the other antipsychotics (72% vs 40% for amisulpride, 33% for olanzapine, 53% for quetiapine, and 45% for ziprasidone; P
<.001). There were no differences in symptom improvement or rates of hospital admission between the treatment groups. Patients treated with haloperidol experienced the most EPSs, and patients treated with olanzapine experienced the most weight gain.10
In the Comparison of Atypicals for First Episode Schizophrenia (CAFE) trial, patients treated with either olanzapine, quetiapine, or risperidone had similar all-cause discontinuation rates at 1 year, no differences in overall symptom severity measures, and side effects similar to those seen in other trials.11
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