Risperidone observational studies

Observational studies In a retrospective comparison of risperidone with haloperidol or trifluoperazine in an Asian population with first-episode schizophrenia-spectrum disorders ( = 261), some 90% discontinued treatment before 18 months however, the median time to discontinuation of risperidone was 69 days compared with 27 days for the first-generation antipsychotic drugs [123 ]. Risperidone had a longer time to discontinuation owing to intolerable adverse reactions than haloperidol and trifluoperazine. Nevertheless, lack of comparability precluded firm conclusions. 

Erdogan A, Karaman MG, Ozdemir E, Yurteri N, Tufan AE, Kurcer MA. Six months of treatment with risperidone may be associated with nonsignificant abnormalities of liver function tests a longitudinal, observational study from Turkey. J Child Adolesc Psychopharmacol 2010 20 407-13. 

Choure BK, Gosavi D, Nanotkar S (2014) Comparative cardiovascular safety of risperidone and olanzapine, based on electrocardiographic parameters and blood pressure a prospective open label observational study. Indian J Pharmacol 46 493 97... 

Observational studies In an open study, 232 children and adolescents (mean age 11 years) with disruptive behavioral disorders were followed during 1 year in an extension period with risperidone, having been previously randomized to risperidone... 

Drug formulations Long-acting injectable risperidone is commonly used in patients with psychoses. There have been two studies sponsored by Janssen Cilag, the risperidone marketing authorization holder. In the first, an observational study in 842 individuals (mean age 41 years), 27% had withdrawn after 6 months because of adverse events (mean dose at end-point 36 mg) [129 ]. 

Observational studies Numerous open studies of ziprasidone promoted by Pfeer, the marketing authorization holder, have previously been published [SEDA-32, 111] and further studies, similarly promoted, have emerged. Of 185 subjects who were switched from olanzapine or risperidone to ziprasidone, 72 completed a 1-year extension study [136 ]. The most common adverse effects were insomnia (23%) and somnolence (11%) no patient had a corrected QT interval over 500 ms at any time during the study. 

Observational Studies A 12-week, open-label study of 58 patients receiving risperidone randomised to continue with risperidone or switch to paliperidone ER found a side-effect profile for paliperidone ER similar to that of risperidone, including metabolic problems and prolactin-related adverse events [18 ]. 

Observational Studies In a 12-week study of children and adolescents with autism spectrum disorders switched from risperidone to aripiprazole, mild somnolence was observed only in one subject and there were no significant changes in vital signs, weight or ECG while serum prolactin levels decreased significantly [90 ]. 

Observational studies An open-label, long-term study of patients switched to oral paliperidone from either risperidone or other antipsychotics found that extrapyramidal symptoms improved significantly for all patients [192 ]. Akathisia and weight gain were the main adverse events, and increased prolactin levels in female patients from the nonrisperidone group. 

Risperidone (11) was also included among a a 1-adrenergic receptor antagonists to study a quantitative structure-activity relationship (99BMC2437). A pharmacophore model for atypical antipsychotics, including 11, was established (00MI41). An increased plasma level of 11 and 9-hydroxyrisperidone (12) was observed in combination with paroxetine (01 MI 13). The effect of vanlafaxine on the pharmacokinetics of 11 was reported (99MI13). 

Antipsychotics in a few small studies have been shown to be helpful. To date this research is limited to typical antipsychotics. Nevertheless, the excellent track record of atypical antipsychotics in treating schizophrenia and the lower burden of side effects lead us to recommend atypical antipsychotics as a first-line treatment for STPD as well. Low doses of risperidone, olanzapine, quetiapine, ziprasidone, or aripiprazole are all reasonable options. If no therapeutic effect is observed, doses should be increased. 

There have been numerous trials of use of the atypical antipsychotics in patients with developmental disabilities, but most of these trials were uncontrolled open-labeled studies or case reports (Aman and Madrid, 1999). Findings were reported for 86 adults and 1 child with prominent self-injury. The reports of adults assessed clozapine (1 report) and risperidone (4 reports). Improvement was observed for a majority of participants in all of these trials. The patients presented with a multitude of conditions, ranging from nonspecific MR and associated behavior problems, to pervasive developmental disorders (including autism), to various psychiatric disorders, including schizophrenia and manic disorder. Self-injury appeared to respond to treatment regardless of concomitant condition. In the only clozapine report with a child (who had autistic disorder), a mean dose of 283 mg/day caused a transient reduction in self-injury. 

There was a significant rise in baseline serum prolactin concentration in 10 patients after they had taken risperidone for a mean of 12 weeks compared with 10 patients who were tested after a neuroleptic drug-free wash-out period of at least 2 weeks (1014). A non-significant increase in serum prolactin has also been observed in an open comparison of risperidone with other neuroleptic drugs in 28 patients (1015). However, in a meta-analysis of two independent studies (n = 404), prolactin was greatly increased by risperidone (mean change 45-80 ng/ml), a larger effect than with olanzapine and haloperidol (1016). 

There has been one comprehensive meta-analysis including over 80 studies and over 30 000 patients (489). A meta-analysis of trials of neuroleptic drugs showed the following mean weight gains in kg after 10 weeks of treatment clozapine, 4.5 olanzapine, 4.2 thioridazine, 3.2 sertindole, 2.9 chlorpromazine, 2.6 risperidone, 2.1 haloperidol, 1.1 fluphenazine, 0.43 ziprasidone 0.04 molindone, —0.39 placebo, —0.74 (490,491). In one study, excessive appetite was a more frequent adverse event in patients treated with olanzapine versus haloperidol (24 versus 12%) (185). Loss of weight has been observed after withdrawal of neuroleptic drugs (492). 

Layton D, Harris S, Wilton LV, Shakir SA. Comparison of incidence rates of cerebrovascular accidents and transient ischaemic attacks in observational cohort studies of patients prescribed risperidone, quetiapine or olanzapine in general practice in England including patients with dementia. J Psychopharmacol 2005 19 473-82. 

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