What is causing the reduced drug-placebo difference in recent schizophrenia clinical trials and what can be done about it?

On September 18, 2007, a collaborative session between the International Society for CNS Clinical Trials and Methodology and the International Society for CNS Drug Development was held in Brussels, Belgium. Both groups, with membership from industry, academia, and governmental and nongovernmental agencies, have been formed to address scientific, clinical, regulatory, and methodological challenges in the development of central nervous system therapeutic agents. The focus of this joint session was the apparent diminution of drug-placebo differences in recent multicenter trials of antipsychotic medications for schizophrenia. To characterize the nature of the problem, some presenters reported data from several recent trials that indicated higher rates of placebo response and lower rates of drug response (even to previously established, comparator drugs), when compared with earlier trials. As a means to identify the possible causes of the problem, discussions covered a range of methodological factors such as participant characteristics, trial designs, site characteristics, clinical setting (inpatient vs outpatient), inclusion/exclusion criteria, and diagnostic specificity. Finally, possible solutions were discussed, such as improving precision of participant selection criteria, improving assessment instruments and/or assessment methodology to increase reliability of outcome measures, innovative methods to encourage greater subject adherence and investigator involvement, improved rater training and accountability metrics at clinical sites to increase quality assurance, and advanced methods of pharmacokinetic/pharmacodynamic modeling to optimize dosing prior to initiating large phase 3 trials. The session closed with a roundtable discussion and recommendations for data sharing to further explore potential causes and viable solutions to be applied in future trials.

Patient-rated troubling symptoms of depression instrument results correlate with traditional clinician- and patient-rated measures: a secondary analysis of a randomized, double-blind, placebo-controlled trial.

BACKGROUND: The Patient-Rated Troubling Symptoms of Depression (PaRTS-D) instrument assesses the presence and troublesomeness of 8 commonly reported depression-related symptoms from the patient's perspective. A post hoc analysis of a double-blind, randomized risperidone augmentation to antidepressant therapy trial in patients with major depressive disorder explored the relationship between the PaRTS-D instrument and other clinician- and patient-rating scales. METHODS: Patients completed the PaRTS-D; the Patient Global Improvement Scale (PGIS), Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), and the Sheehan Disability Scale (SDS), while clinicians completed the Hamilton Rating Scale for Depression (HRSD-17), and the Clinical Global Impressions of Severity (CGI-S) at baseline and at pre-determined study weeks. RESULTS: In the PaRTS-D instrument, the four most frequently reported and troublesome symptoms were sadness (73.5%, severity 6.8), trouble concentrating (70.9%, 7.3), reduced involvement in pleasurable activities (61.9%, 7.3), and being tense or uptight (56.0%, 6.7). The improvement in PaRTS-D total score was significantly greater in risperidone-augmented compared with placebo-augmented patients at week 4 (p=0.034) and week 6 (p=0.007). Pearson correlations between the PaRTS-D scores and the measures of HRSD-17, CGI-S, PGIS, Q-LES-Q, and SDS were significant at both baseline and at week 6 LOCF (p<0.001 for each comparison). LIMITATIONS: Results are from a post hoc analysis. CONCLUSIONS: Significant correlations were observed between the PaRTS-D and other clinician- and patient-rated measures, with PaRTS-D being sensitive to the effects of treatment. These findings suggest that the PaRTS-D instrument is a reliable scale to assess antidepressant activity as experienced by the patients.

Psychometric evaluation of a patient-rated troubling symptom scale for generalized anxiety disorder clinical trials.

BACKGROUND: The majority of clinical outcome assessments developed for generalized anxiety disorder (GAD) may not efficiently and sensitively reflect heterogeneous symptom clusters from a patient perspective. The Patient-Rated Troubling Symptoms Scale for Anxiety (PaRTS-A) instrument was developed to provide an individualized assessment of patient relevant GAD symptoms. OBJECTIVE: The objective of this analysis was to evaluate the psychometric characteristics of the PaRTS-A. METHODS: Data were taken from a 6-week clinical trial evaluating the efficacy of adjunctive risperidone therapy in GAD patients undergoing standard treatment. Patients completed the PaRTS-A, the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), and the Sheehan Disability Scale (SDS) as well as impressions of improvement. Physicians completed the Hamilton Anxiety Rating Scale (HAM-A). A instrument characteristics were assessed through statistical tests of reliability, reproducibility, construct and discriminant validity, and responsiveness. RESULTS: In the item response theory (IRT) analysis, the PaRTS-A items fit into a single construct of anxiety. Internal consistency reliability exceeded 0.70. The PaRTS-A total score was moderately correlated with the Q-LES-Q and the SDS. The PaRTS-A distinguished between patients with high and low HAM-A scores (p<0.001). The PaRTS-A was responsive to changes in clinical status and the minimal important difference was identified. CONCLUSION: The PaRTS-A provides a unique patient-rated assessment of anxiety symptoms. The instrument may provide clinicians with useful information regarding patient's self-rated anxiety disorder symptoms and the hierarchy of symptoms that they considered most troubling. Our analysis suggests that the PaRTS-A is an internally consistent, valid, and responsive instrument that may be a beneficial adjunct to other instruments in clinical trials.

Anticholinergic activity of 107 medications commonly used by older adults.

The objective of this study was to measure the anticholinergic activity (AA) of medications commonly used by older adults. A radioreceptor assay was used to investigate the AA of 107 medications. Six clinically relevant concentrations were assessed for each medication. Rodent forebrain and striatum homogenate was used with tritiated quinuclidinyl benzilate. Drug-free serum was added to medication and atropine standard-curve samples. For medications that showed detectable AA, average steady-state peak plasma and serum concentrations (C(max)) in older adults were used to estimate relationships between in vitro dose and AA. All results are reported in pmol/mL of atropine equivalents. At typical doses administered to older adults, amitriptyline, atropine, clozapine, dicyclomine, doxepin, L-hyoscyamine, thioridazine, and tolterodine demonstrated AA exceeding 15 pmol/mL. Chlorpromazine, diphenhydramine, nortriptyline, olanzapine, oxybutynin, and paroxetine had AA values of 5 to 15 pmol/mL. Citalopram, escitalopram, fluoxetine, lithium, mirtazapine, quetiapine, ranitidine, and temazepam had values less than 5 pmol/mL. Amoxicillin, celecoxib, cephalexin, diazepam, digoxin, diphenoxylate, donepezil, duloxetine, fentanyl, furosemide, hydrocodone, lansoprazole, levofloxacin, metformin, phenytoin, propoxyphene, and topiramate demonstrated AA only at the highest concentrations tested (patients with above-average C(max) values, who receive higher doses, or are frail may show AA). The remainder of the medications investigated did not demonstrate any AA at the concentrations examined. Psychotropic medications were particularly likely to demonstrate AA. Each of the drug classifications investigated (e.g., antipsychotic, cardiovascular) had at least one medication that demonstrated AA at therapeutic doses. Clinicians can use this information when choosing between equally efficacious medications, as well as in assessing overall anticholinergic burden.

Ethnic heterogeneity in glucoregulatory function during treatment with atypical antipsychotics in patients with schizophrenia.

OBJECTIVE: Atypical antipsychotics induce weight gain and are linked to increased diabetes risk, but their relative impact on factors that elevate disease risk are unknown. METHODS: We performed a 6-month, randomized, double-blind study to evaluate the effects of risperidone and olanzapine in patients with schizophrenia. At baseline and weeks 6 and 24, we quantified: (1) total adiposity by DEXA, (2) visceral adiposity by abdominal CT, and (3) insulin sensitivity (SI) and (4) pancreatic function ("disposition index", DI) by intravenous glucose tolerance test. RESULTS: At baseline, groups (risperidone: n=28; olanzapine: n=31) were overweight or obese by body mass index (risperidone: 28.4+/-5.4, olanzapine: 30.6+/-7.0kg/m2). Both drugs induced weight gain (p<0.004). Total adiposity was increased by olanzapine at 6 weeks (p=0.0006) and by both treatments at 24 weeks (p<0.003). Visceral adiposity was increased by olanzapine and risperidone by 24 weeks (p<0.003). S(I) did not deteriorate appreciably, although a downward trend was observed with risperidone. Given known ethnic differences in adiposity and S(I), we performed secondary analysis in African American and Hispanic subjects. In this subset, olanzapine expanded both total and visceral adiposity (p<0.02); no increase was observed with risperidone. There were modest downward trends for SI with both treatments. By week 24, olanzapine-treated subjects exhibited diminished DI (p=0.033), indicating inadequate pancreatic compensation for insulin resistance. CONCLUSIONS: This is the first prospective study in psychiatric patients that quantified antipsychotic effects on the multiple metabolic processes that increase diabetes risk. Results indicate that ethnic minorities may have greater susceptibility to antipsychotic-induced glucoregulatory complications.

Placebo-controlled study of relapse prevention with risperidone augmentation in older patients with resistant depression.

OBJECTIVE: The effect of risperidone augmentation of citalopram for relapse prevention in older patients with antidepressant-resistant depression was evaluated. METHODS: Patients with major depression aged > or =55 years who had failed at least one adequate trial of an antidepressant received citalopram monotherapy (20-40 mg) for 4 to 6 weeks to confirm nonresponse (<50% reduction in Hamilton Rating Scale for Depression [HAM-D] scores). Those who achieved remission (HAM-D score < or =7 or Clinical Global Impressions severity score 1 or 2) after 4 to 6 weeks of open-label risperidone augmentation (0.25-1 mg) then entered a 24-week double-blind maintenance phase during which they received citalopram augmented with risperidone or placebo. RESULTS: The patients' mean age was 63.4 +/- 7.9 years; 58% were women; 61% had received two or more antidepressants during the current episode; 93 met the criterion for citalopram nonresponse and entered open-label risperidone augmentation. Of the 89 patients who completed risperidone augmentation, 63 achieved symptom resolution and entered the 6-month double-blind maintenance phase: 32 received risperidone augmentation and 31 received placebo augmentation. The median time to relapse (Kaplan-Meier estimates) was 105 days in the risperidone group and 57 days in the placebo group (Wilcoxon chi(2): 3.2, df = 1, p = 0.069). Overall, 18 of 32 (56%) from the risperidone group and 20 of 31 (65%) from the placebo group relapsed. Treatment was well tolerated. CONCLUSION: In older patients with resistant depression and poor response to standard treatments, risperidone augmentation resulted in symptom resolution in a substantial number of patients and a nonsignificant delay in time to relapse.

The impact of insight on functioning in patients with schizophrenia or schizoaffective disorder receiving risperidone long-acting injectable.

This post hoc analysis explored the role of insight as a mediator of functioning in a 52-week, double-blind, international trial of 323 patients with schizophrenia or schizoaffective disorder receiving risperidone long-acting injectable. Measures included the Positive and Negative Syndrome Scale (PANSS) insight item, PANSS factors, Clinical Global Impressions-Severity (CGI-S), Strauss-Carpenter Levels of Functioning (LOF), Personal and Social Performance (PSP) scale, and a cognitive test battery. Correlation/regression analyses examined associations between demographic and clinical characteristics, including insight, and functional measures. Insight scores correlated significantly with CGI-S, PANSS subscales, PSP, LOF, and several cognitive measures. Regression models demonstrated that changes in insight, changes in negative symptoms, and study duration were significantly associated with PSP and LOF total change scores. Findings identified important variables to consider for intervention to improve functioning in schizophrenia.

Incidence and costs of polypharmacy: data from a randomized, double-blind, placebo-controlled study of risperidone and quetiapine in patients with schizophrenia or schizoaffective disorder.

OBJECTIVE: The use of adjunctive psychotropics and the costs of polypharmacy in patients randomized to receive risperidone or quetiapine were compared in a placebo-controlled double-blind study conducted in India, Romania, and the United States. METHODS: The efficacy and safety of risperidone, quetiapine, and placebo were compared in a 14-day monotherapy phase in patients experiencing an acute exacerbation of symptoms of schizophrenia or schizoaffective disorder. This was followed by a 28-day, additive-therapy phase during which addition of antipsychotics or other psychotropic medications was permitted. Risperidone was received by 153 patients in the monotherapy phase and 133 in the additive therapy phase, quetiapine by 156 and 122, respectively, and placebo by 73 and 53. Rates of polypharmacy were examined using the Cochran-Mantel-Haenszel, Kaplan-Meier, and Cox regression methods. Costs of polypharmacy were analyzed by non-parametric Wilcoxon 2-sample tests. RESULTS: Primary study results have been reported elsewhere (Potkin et al., Schizophr Res 2006;85:254-65). Mean (+/-SD) doses at the additive-therapy baseline were 4.7 +/- 0.9 mg/day of risperidone and 579.0 +/- 128.9 mg/day of quetiapine. Additional psychotropics were received by 36% of the risperidone group, 58% of the quetiapine group (p < 0.01), and by 58% of the placebo group. Antipsychotics accounted for > 95% of the added psychotropics, the most common being olanzapine and haloperidol. The relative risk (quetiapine vs. risperidone) for antipsychotic polypharmacy was 1.90 (p = 0.001; 95% CI 1.29, 2.80). The mean projected cost of additional antipsychotics per randomized patient during the additive-therapy phase was $57.03 in the risperidone group and $101.64 in the quetiapine group (p < 0.01). CONCLUSIONS: The results confirm earlier reports of higher rates of polypharmacy with quetiapine than with risperidone. The findings also reveal substantial between-treatment differences in costs associated with polypharmacy. Limitations of the study include that the study was of short duration and that a high proportion of patients were recruited from countries other than the United States.

Cognitive functioning and acute sedative effects of risperidone and quetiapine in patients with stable bipolar I disorder: a randomized, double-blind, crossover study.

OBJECTIVE: Antipsychotic medications differ in their sedative potential, which can affect cognitive performance. The primary objective of this double-blind study was to compare the effects of treatment initiation with risperidone and quetiapine on cognitive function in subjects with stable bipolar disorder. METHOD: Subjects had a DSM-IV diagnosis of bipolar I disorder in partial or full remission and a Young Mania Rating Scale score

Evaluating movement disorders in pediatric patients receiving risperidone: a comparison of spontaneous reports and research criteria for TD.

BACKGROUND: Movement disorders (MD) in children are relatively common and may be associated with medication use. Objective methods (ie rating scales) and specific research criteria may be helpful in identifying MD-related adverse events that would otherwise not be apparent from spontaneous reports. We assessed whether more stringent and rigorous criteria would provide MD rates similar to those derived subjectively from spontaneous reports. METHODS: MDs were assessed in children with disruptive behavior disorders (DBDs) and subaverage intelligence receiving risperidone. Data were from three 1-year, open-label studies in subjects 4-14 years old. Dyskinesia severity was rated by the Extrapyramidal Symptom Rating Scale (ESRS) dyskinesia subscale. Tardive dyskinesia (TD) was defined: mild dyskinesia (scores 2, 3) in two anatomical areas; or moderate dyskinesia (score >or= 4) in one area for >or= 4 weeks in subjects without dyskinesia at baseline (scores 0, 1). RESULTS: The mean (+/- SD) age of subjects was 9.4 +/- 2.4 years, the mean (+/- SD) risperidone dose was 1.6 +/- 0.7 mg/day, and the mean (+/- SD) exposure was 317.8 +/- 104.5 days. ESRS data were available for 668 subjects. Mean ESRS scores were low throughout the study. At baseline, 655 subjects had no dyskinetic symptoms. One subject met predefined TD criteria after a risperidone dose reduction. Symptoms persisted for 4 weeks, resolving with continued treatment and no dosage change. Two different subjects had TD by spontaneous adverse-event reports, with dyskinetic symptoms at 1-2 visits, and symptoms that resolved after treatment discontinuation. Thirteen subjects had dyskinesia at baseline; their mean ESRS dyskinesia scores decreased at endpoint. CONCLUSION: Using objective rating scales and research criteria, low-dose risperidone was associated with low risk of TD and other MDs in children with DBDs in three large 1-year studies. Careful, objective evaluation of emergent MDs during all stages of treatment is essential for identifying treatment-emergent TD.

Risperidone and cognitive function in children with disruptive behavior disorders.

BACKGROUND: Effects of risperidone on cognitive function in children with disruptive behavior disorders (DBDs) and subaverage intelligence quotient (IQ) were assessed. METHODS: Data from two 6-week, double-blind, placebo-controlled studies (n = 228) were combined, as were three 1-year, open-label studies (n = 688). Patients with DBDs and subaverage IQ, 5 to14 years, received placebo or risperidone .02 to .06 mg/kg/day. Cognitive measures included the Continuous Performance Task (CPT) and Verbal Learning Test for Children (VLT-C). Efficacy was assessed using the Nisonger Child Behavior Rating Form (NCBRF). Adverse events were collected via spontaneous report; sedation was assessed using visual analog scale. RESULTS: Improvements on the NCBRF Conduct Problem subscale were significantly greater for risperidone- versus placebo-treated patients (-15.8 vs. -6.4, p < .0001) in short-term studies; significant reductions were observed in long-term studies (-16.3, p < .0001). No overall decline and some significant improvement in attention (CPT) and memory (VLT-C) were noted regardless of treatment in short-term studies. VLT-C improved significantly (p < .0001) for both groups, with no difference between treatment groups. Improvements in memory (VLT-C) and attention (CPT) were noted in long-term studies. Somnolence/sedation did not affect cognitive function. CONCLUSIONS: Cognitive function was not altered by risperidone in short-term studies and was maintained or improved with one year of treatment in children with DBDs and subaverage IQ, potentially representing age-appropriate gains.

Maintenance therapy with once-monthly administration of long-acting injectable risperidone in patients with schizophrenia or schizoaffective disorder: a pilot study of an extended dosing interval.

BACKGROUND: Several clinical studies have established the efficacy, safety, and tolerability of long-acting risperidone administered once every 2 weeks in patients with schizophrenia or schizoaffective disorder. This report evaluates preliminary efficacy, safety, tolerability, and pharmacokinetic data for a novel (once-monthly) administration of long-acting injectable risperidone 50 mg in patients with schizophrenia or schizoaffective disorder. METHODS: Clinically stable patients participated in a 1-year, open-label, single-arm, multicenter pilot study. During the 4-week lead-in phase, patients received long-acting risperidone 50 mg injections every 2 weeks, with 2 weeks of oral risperidone supplementation. Injections of long-acting risperidone 50 mg every 4 weeks followed for up to 48 weeks, without oral supplementation. The primary endpoint was relapse; other assessments included PANSS, CGI-S, adverse event reports, and determination of risperidone and 9-hydroxyrisperidone plasma concentrations. RESULTS: Twelve patients in the intent-to-treat population (n = 67) met relapse criteria (17.9%). Relapse risk at 1 year was estimated as 22.4%. Non-statistically significant improvements in symptoms (PANSS) and clinical status (CGI-S) at endpoint were observed. The most common adverse events included schizophrenia aggravated not otherwise specified (19.5%), anxiety (16.1%), insomnia (16.1%), and headache (11.5%). There were no unexpected safety and tolerability findings. Mean plasma concentrations for risperidone and 9-hydroxyrisperidone were generally stable during the study. CONCLUSION: Once-monthly dosing of long-acting risperidone was well tolerated, associated with a relatively low relapse rate (similar to that reported with other antipsychotics), and maintained the clinically stable baseline status of most patients. Although the results suggest that some symptomatically stable patients with schizophrenia or schizoaffective disorder might be safely managed with long-acting risperidone 50 mg once monthly, these findings alone do not identify which patients will have a sufficient therapeutic benefit nor do they quantify comparative effects of standard and altered dosing. Study limitations (the open-label pilot study design, small sample size, and lack of a concurrent biweekly treatment arm) prevent broad interpretations and extrapolations of results. Controlled studies would be required to support a recommendation for alternative dosing regimens.

Patient-based and clinician-based support for the remission criteria in schizophrenia.

This analysis characterizes patients with schizophrenia or schizoaffective disorder treated with risperidone who met remission criteria. In a 50-week, open-label trial, stable patients received long-acting injectable risperidone every 2 weeks. Remission criteria included severity (absent-mild ratings on core symptoms of the Positive and Negative Syndrome Scale) and duration (> or =6 months) components. The patients not remitted (severity component only) at baseline (n=394) are the subjects of this report. Measures applied included the PANSS, Clinical Global Impressions-Severity, patient-rated mental health status (Short Form-36), and Drug Attitude Inventory. Among patients who met remission criteria during the study (n=82), mean scores for all 30 PANSS items reflected absent-mild ratings at endpoint. The highest items represented an 'interpersonal' cluster, although mean ratings were still minimal to mild. Remitted patients experienced substantial improvements in Short Form-36 and Drug Attitude Inventory scores at endpoint. Although improvement occurred, it was less robust in patients who remained nonremitted (n=312). Logistic regression analysis found that remission (severity component only) was associated with a 97.1% probability of a 'not ill' rating on the Clinical Global Impressions-Severity. These remission criteria identified patients who differed from the nonremitted population on symptoms of psychopathology, medication attitude, health status, and overall clinical status, supporting the clinical validity of the remission criteria.

Reduction in psychotic symptoms as a predictor of patient satisfaction with antipsychotic medication in schizophrenia: data from a randomized double-blind trial.

BACKGROUND: Patient satisfaction with antipsychotic treatment is important. Limited evidence suggests that satisfaction is associated with symptom improvement and compliance. Predictors of patient satisfaction with antipsychotic medication were examined in a study of patients with a recent exacerbation of schizophrenia. METHODS: Data are from a randomized, double-blind trial comparing risperidone (n = 152), quetiapine (n = 156), and placebo (n = 73). Medication Satisfaction Questionnaire (MSQ) was completed after 14 days of treatment and after 6 weeks at last study visit. RESULTS: Medication satisfaction at both time points was significantly associated in multiple regression analysis with improvement on 3 Positive and Negative Syndrome Scale (PANSS) factor scores (positive symptoms p < .01; uncontrolled hostility/excitement, p < .0005; anxiety/depression, p < .04) and treatment with risperidone (p < .03); at day 14, significant association was also found with older age (p = .01). At both time points, predictor variables explained over 30% of the variance in medication satisfaction. Change in Hamilton Depression Scale, prolactin levels, sex, and reported adverse events of extrapyramidal symptoms, sedation, and movement disorders were not significant predictors of satisfaction. Lower level of medication satisfaction at day 14 was associated with earlier discontinuation in the trial at week 6 end point. A focused principal components analysis of PANSS factors and MSQ suggested that medication satisfaction relates to 3 groups of factors in descending order of magnitude: lower levels of (a) uncontrolled hostility/excitement, (b) positive symptoms, and (c) negative symptoms, disorganized thoughts, and anxiety/depression. CONCLUSION: Results give further support that treatment satisfaction is positively associated with symptom improvement, particularly psychotic symptoms, and suggest that satisfaction may also be related to compliance, as those who were more satisfied remained in the trial for a longer period of time.

A 1-year double-blind study of 2 doses of long-acting risperidone in stable patients with schizophrenia or schizoaffective disorder.

OBJECTIVE: This study examined the effects of 2 doses of long-acting risperidone injection in patients with schizophrenia or schizoaffective disorder. METHOD: This 52-week, prospective, randomized, double-blind, multicenter, international study included clinically stable outpatients with schizophrenia or schizoaffective disorder (DSM-IV criteria). Settings included physicians' offices and clinics. Patients received a fixed dose of long-acting risperidone (25 or 50 mg) every 2 weeks. Primary outcome was time to relapse, defined as either re-hospitalization or other exacerbation criteria. Other assessments included the Positive and Negative Syndrome Scale, Clinical Global Impressions-Severity of Illness scale, and functional and quality-of-life measures. Safety was assessed via treatment-emergent adverse events, laboratory tests, and movement disorder rating scales. Data were collected from December 2002 to September 2004. RESULTS: A total of 324 patients were randomized to 25 mg (N = 163) or 50 mg (N = 161) of long-acting risperidone. Time to relapse was comparable (p = .131) for both groups. Projected median time to relapse was 161.8 weeks (95% CI = 103.0 to 254.2) with 25 mg and 259.0 weeks (95% CI = 153.6 to 436.8) with 50 mg. One-year incidences of relapse were 21.6% (N = 35) and 14.9% (N = 24), respectively (p = .059). Psychiatric hospitalization was the reason for relapse for 16 (10%) in the 25-mg group and 10 (6%) in the 50-mg group. Patients experienced statistically significant but modest improvements at endpoint in most measures (i.e., psychotic symptoms, functioning, movement disorder severity) with both doses, with no significant between-group differences. CONCLUSION: In this 1-year study, long-acting risperidone was associated with low relapse and rehospitalization rates, indicating that doses of 25 to 50 mg are appropriate for long-term treatment in schizophrenia.

A model of anticholinergic activity of atypical antipsychotic medications.

BACKGROUND: Atypical antipsychotics clozapine, olanzapine, and quetiapine have significant affinity for the muscarinic receptors in vitro, while aripiprazole, risperidone, and ziprasidone do not. Dissimilarity in binding profiles may contribute to the reported differences in the anticholinergic effects of these antipsychotics. However, it is difficult with the available data to predict the likelihood of anticholinergic effects occurring with various doses of an atypical antipsychotic. METHODS: We developed a model to assess the potential anticholinergic activity (AA) of atypical antipsychotics at therapeutic doses. A radioreceptor assay was used to measure in vitro AA at 6 clinically relevant concentrations of aripiprazole, clozapine, olanzapine, quetiapine, risperidone, and ziprasidone. Using published pharmacokinetic data, in combination with the measured in vitro AA, dose-AA curves were generated. RESULTS: Clozapine, and to a lesser extent olanzapine and quetiapine showed dose-dependent increases in AA. At therapeutic doses, the AA (in pmol/mL of atropine equivalents) was estimated to range from 27-250, 1-15, and 0-5.4 pmol/mL for clozapine, olanzapine, and quetiapine, respectively. Aripiprazole, risperidone, and ziprasidone did not demonstrate AA at any of the concentrations studied. CONCLUSIONS: Therapeutic doses of clozapine, olanzapine, and, to a lesser extent, quetiapine are associated with clinically relevant AA.

A double-blind comparison of risperidone, quetiapine and placebo in patients with schizophrenia experiencing an acute exacerbation requiring hospitalization.

OBJECTIVE: This study compared the effects of atypical antipsychotics (risperidone or quetiapine) with placebo and with each other in recently exacerbated patients with schizophrenia requiring hospitalization. METHODS: This international, randomized, double-blind study included a 2-week monotherapy phase followed by a 4-week additive therapy phase. Recently exacerbated patients with schizophrenia or schizoaffective disorder (DSM-IV) were randomized (2:2:1) to risperidone (n = 153), quetiapine (n = 156), or placebo (n = 73). Target doses were 4 or 6 mg/day of risperidone and 400 or 600 mg/day of quetiapine by day 5, with the ability to increase to 600 or 800 mg/day of quetiapine on day 8. The main outcome measures were the total Positive and Negative Syndrome Scale (PANSS) and need for additional psychotropic medications. RESULTS: Monotherapy Phase: The combined atypical antipsychotic group (n = 308) reached borderline superiority to placebo (n = 71) at the 2-week endpoint on mean change in total PANSS score (-24.1 +/- 1.2 and -20.2 +/- 2.0, respectively; p = 0.067). The change in the atypical group was driven by the improvement with risperidone (-27.7 +/- 1.5 vs. -20.2 +/- 2.0 with placebo, p < 0.01; and vs. -20.5 +/- 1.5 with quetiapine, p < 0.01); the improvement with quetiapine was similar to placebo, p = 0.879. Results were similar on other efficacy endpoints. Additive Therapy Phase: Additional psychotropics were prescribed to fewer (p < 0.01) risperidone (36%) than quetiapine (53%) or placebo patients (59%). The overall discontinuation rate was 18%, 26%, and 38%, respectively. Risperidone, compared with placebo, was associated with more parkinsonism, akathisia, plasma prolactin changes, and weight gain; while quetiapine was associated with more somnolence, sedation, dizziness, constipation, tachycardia, thyroid dysregulation, and weight gain. CONCLUSION: While the combined atypical antipsychotic group did not experience greater improvements than the placebo group, risperidone, but not quetiapine, was significantly superior in all measured domains to placebo in the management of recently exacerbated hospitalized patients with schizophrenia or schizoaffective disorder, with no unexpected tolerability findings.

Effects of risperidone augmentation in patients with treatment-resistant depression: Results of open-label treatment followed by double-blind continuation.

Approximately one-third of persons with depression do not respond to antidepressant monotherapy. Studies suggest that atypical antipsychotic augmentation may benefit these patients. We investigated the longer-term efficacy of risperidone augmentation of serotonin-selective reuptake inhibitor treatment for resistant depression. In 57 in- and outpatient centers in three countries, we conducted a three-phase study with 4-6 weeks of open-label citalopram monotherapy, 4-6 weeks of open-label risperidone augmentation, and a 24-week double-blind, placebo-controlled discontinuation phase. A total of 489 patients with major depressive disorder and 1-3 documented treatment failures entered the citalopram monotherapy phase (20-60 mg/day). Patients with <50% reduction in HAM-D-17 scores entered the risperidone augmentation phase (0.25-2.0 mg/day). Patients with HAM-D-17< or =7 or CGI-S < or = 2 were randomized to risperidone or placebo augmentation. The primary outcome was time to relapse during the double-blind phase. During citalopram monotherapy, 434 patients had <50% HAM-D-17 reduction; 299 (68.9%) were fully nonresponsive (<25% reduction) and 135 were partially nonresponsive (25-49% reduction). Of the 386 nonresponders who entered the augmentation phase, 243 remitted and 241 entered the double-blind phase. Median time to relapse was 102 days with risperidone augmentation and 85 days with placebo (NS); relapse rates were 53.3 and 54.6%, respectively. In a post hoc analysis of patients fully nonresponsive to citalopram monotherapy, median time to relapse was 97 days with risperidone augmentation and 56 with placebo (p = 0.05); relapse rates were 56.1 and 64.1%, respectively (p < or = 0.05). Open-label risperidone augmentation substantially enhanced response in treatment-resistant patients, but the longer-term benefits of augmentation were not demonstrated in this study.

Insight and its relationship to clinical outcomes in patients with schizophrenia or schizoaffective disorder receiving long-acting risperidone.

Poor insight is common in schizophrenia, predictive of non-compliance, and an impediment to effective patient management. We hypothesized that long-acting risperidone would be associated with enhanced insight, contributing to improved quality of life measures. In an international, open-label 50-week study, stable patients received long-acting risperidone every 2 weeks. Assessments included the Positive and Negative Syndrome Scale [PANSS; item G12 rated 'impaired insight and judgment' from 1 (no impairment) to 7 (severe impairment)]; Clinical Global Impressions-Severity (CGI-S); and the Medical Outcomes Study Short-form 36-item Health Survey (SF-36) (patient-rated quality of life). Correlation and regression post-hoc analyses examined associations between insight and other measures. At baseline, 314 (51.1%; N=614) patients had impaired insight (G12=3-7) and 83 (26.4%) achieved normal or near normal ratings at endpoint (G12=1-2). Symptom severity corresponded with insight: baseline mean+/-SD PANSS total scores were 56.0+/-14.4 in patients without impaired insight (G12=1-2); 73.4+/-15.7 with mild-moderate impairment (G12=3-4); and 86.0+/-17.4 with severe impairment (G12=5-7). These scores improved significantly in each group at endpoint (P<0.001). Improved insight ratings correlated with improvements in CGI-S (r=0.37); PANSS disorganized thought (r=0.46); negative symptoms (r=0.32); and anxiety/depression (r=0.24; P<0.001 all comparisons), but not quality of life ratings. The change in insight did not contribute significantly to the variance in SF-36 scores; however, changes in negative symptoms, anxiety/depression and CGI-S scores did contribute significantly. Long-acting risperidone was associated with improvements in insight, symptom domains, clinical status and quality of life measures. Associations were noted between patient-rated quality of life and specific symptom domains, but not insight.