Georges M. Gharabawi

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 (Cmax) 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 Cmax 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.

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.

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⩽7 or CGI-S⩽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⩽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.

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.

International multisite double-blind trial of the atypical antipsychotics risperidone and olanzapine in 175 elderly patients with chronic schizophrenia.

OBJECTIVE The authors compared the effects of the two most commonly used atypical antipsychotics, risperidone and olanzapine, in elderly patients with schizophrenia. METHODS In an 8-week, international, double-blind study, patients (outpatients, hospital inpatients, and residents of nursing or boarding homes) were randomly assigned to receive risperidone (1 mg to 3 mg/day) or olanzapine (5 mg to 20 mg/day). The main outcome measures were changes in Positive and Negative Syndrome Scale (PANSS) total scores and rates of extrapyramidal symptoms (EPS). RESULTS Subjects were 175 patients age 60 years or over with schizophrenia or schizoaffective disorder. The mean duration of illness was 36.5 years. Median doses were 2 mg/day of risperidone and 10 mg/day of olanzapine. PANSS total scores and four of the five PANSS factor scores (positive symptoms, negative symptoms, disorganized thoughts, and anxiety/depression) improved significantly at all time-points and at endpoint in both groups; between-treatment differences were not significant. EPS-related adverse events were reported by 9.2% of patients in the risperidone group and 15.9% in the olanzapine group; the between-treatment difference was not significant. Total scores on the Extrapyramidal Symptom Rating Scale were reduced in both groups at endpoint; between-treatment differences were not significant. Clinically relevant weight gain was seen in both groups, but was significantly less frequent in risperidone patients than in olanzapine patients. CONCLUSIONS Stable elderly patients with chronic schizophrenia receiving appropriate doses of risperidone or olanzapine over an 8-week period experienced significant reductions in the severity of psychotic and extrapyramidal symptoms, with a relatively low risk of side effects.

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.

Clinical improvement in 336 stable chronically psychotic patients changed from oral to long-acting risperidone: a 12-month open trial

Modern atypical antipsychotics have advantages over older neuroleptics. We hypothesize that their utility may be further enhanced by sustained drug delivery without daily oral self-dosing. This report examines the effects of a year of treatment with long-acting risperidone for chronically psychotic patients previously stabilized with oral risperidone. This open trial of long-acting risperidone involved 336 patients diagnosed with DSM-IV schizophrenia or schizoaffective disorder judged clinically stable on a consistent daily oral dose of risperidone for > or =4 wk. Based on oral doses, subjects were assigned clinically to bi-weekly intramuscular injections of 25-75 mg of long-acting risperidone for up to 50 wk. Clinical assessments at regular intervals included the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impressions (CGI) scale, adverse event reports, and the Extrapyramidal Symptom Rating Scale (ESRS). PANSS total scores improved overall from a moderate baseline score of 64.5+/-17.7 to 58.8+/-19.9 at end-point (p<0.001), by> or =20% in 50% of patients, with greatest improvement in negative symptoms. Prevalence of favourable CGI - Severity ratings increased by 2.4-fold (p<0.0001). Ratings of extrapyramidal symptoms also improved [e.g. physician-rated parkinsonism scores decreased by 20% (p<0.0001)]. Tissue reactions and other adverse effects of repeated intramuscular injections were rare and mild. Psychotic patients considered stable but symptomatic with oral risperidone treatment showed further improvements in symptom ratings and extrapyramidal dysfunction during a year of bi-weekly injections of long-acting risperidone.

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

BackgroundPatient 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.MethodsData 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.ResultsMedication 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.ConclusionResults 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.Trial registration numberTrial registration number NCT00061802

An assessment of emergent tardive dyskinesia and existing dyskinesia in patients receiving long-acting, injectable risperidone: Results from a long-term study

INTRODUCTION Treatment-emergent tardive dyskinesia (TD) can be a serious side effect of antipsychotic treatment. Atypical antipsychotics are associated with a lower risk for TD than are conventional agents. A long-acting atypical antipsychotic, with more stable blood levels and lower peak blood levels than an oral formulation, may provide differential benefit regarding side effects, including movement disorders. This analysis assessed TD by defined research criteria in patients receiving long-acting, injectable risperidone. METHODS Clinically stable subjects with schizophrenia or schizoaffective disorder participated in a 50-week, open-label trial of long-acting, injectable risperidone. TD was studied by defined research criteria (Schooler, N.R., Kane, J.M., 1982. Research diagnosis for tardive dyskinesia. Arch. Gen. Psychiatry. 39, 486-487; Americal Psychiatric Association, 2000. Diagnostic and Statistical Manual of Mental Disorders, fourth ed. American Psychiatric Association, Washington, DC). The severity of dyskinesia and other movement disorders were rated by the Extrapyramidal Symptom Rating Scale (ESRS). RESULTS ESRS dyskinesia data were available for 662 patients. Five of 530 subjects without dyskinesia at baseline (0.94%) met the predefined criteria for emergent persistent TD during therapy. Based on either exposure to study medication or Kaplan-Meier analysis, the 1-year rate was 1.19%. Among the 132 subjects with dyskinesia at baseline, the mean score on the ESRS physicians exam for dyskinesia improved significantly at endpoint (-2.77; P<0.0001), regardless of anticholinergic drug use. (P=0.243 for patients with versus without anticholinergic drug use.) CONCLUSIONS In this open-label study, treatment with long-acting risperidone was associated with a low rate of emergent persistent TD. Significant improvement in existing dyskinesias was noted. The TD rate reported here is consistent with other reports of atypical antipsychotics and substantially lower than with conventional antipsychotics.

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.