Risperidone akathisia from

In general, lower doses (e.g., risperidone 2 to 6 mg/day olanzapine 5 to 20 mg/day) are preferable, usually sufficient, and help avoid toxicity. At these doses, results suggest that olanzapine has a substantially lower propensity than neuroleptics to evoke EPS, and perhaps TD. Indeed, early clinical trials were unable to distinguish olanzapine from placebo for EPS or akathisia. Further, there is some indication that doses of risperidone 10 mg may produce less improvement and more side effects than doses in the 4-8 mg dose range. 

In CONCLUSION, the use of the "classical" neuroleptics, as exemplified by the phenothiazines, thioxanthines, butyrophenones and diphenylbutyl-piperidines, has been a landmark in the pharmacotherapy of schizophrenia and psychotic disorders. The efficacy of such drugs in the alleviation of the symptoms of schizophrenia is universally accepted. However, it is also evident that they have a spectrum of adverse effects that frequently renders their long-term use problematic. Side effects such as akathisia, Parkinsonism, tardive dyskinesia and the all too frequent changes in peripheral autonomic activity are largely predictable from the structure of the molecules and the basic animal pharmacology data. Such adverse effects, and the difficulties encountered when attempting to reduce their frequency and severity by concurrent medication, has stimulated the development of "atypical" neuroleptics such as clozapine and risperidone which, hopefully, will combine efficacy with a reduction in side effects. 

Clozapine has also been compared with risperidone in 60 treatment-resistant patients with schizophrenia in India (16). There was clinical improvement (a more than 20% reduction from baseline PANSS scale scores) in 80% of the clozapine-treated patients and 67% of the risperidone-treated patients. The predominant adverse effects with clozapine (n = 30) were tachycardia (77%), hypersalivation (60%), sedation (60%), weight gain (43%), and constipation (30%) one patient had a seizure. The adverse effects of risperidone (n = 30) were constipation (50%), dry mouth (47%), weight gain (43%), akathisia (37%), insomnia (33%), tachycardia (30%), and impotence (27%). The final mean daily doses after 16 weeks of treatment were 343 mg for clozapine and 5.8 mg for risperidone. 

In a 6-month multicenter study in 96 manic patients (mean age 41 years 50% women) who took risperidone monotherapy 4.2 mg/day, 16 withdrew from the study, in four cases because of adverse events akathisia, impotence, drowsiness, and weight gain (28). 

A pharmacokinetic interaction of risperidone with fluoxetine has been reported (SEDA-22, 71). When 10 schizophrenic patients stabilized on risperidone 4-6 mg/day took fluoxetine 20 mg/day for concomitant depression the mean plasma risperidone concentration increased from 12 to 56 ng/ml at week 4 the concentration of 9-hydroxyrisperidone was not significantly affected (169). One patient dropped out after 1 week because of akathisia associated with a markedly increased plasma risperidone concentration. 

A pharmacokinetic study in 10 patients found that fluoxetine 20 mg daily raised the levels of risperidone 2 or 3 mg twice daily from 12 to 19 nanograms/mL after 3 weeks and to 56 nanograms/mL after 4 weeks. All patients experienced a rise in risperidone levels, but this varied from two to tenfold. One patient withdrew from the study because of severe akathisia and another two patients needed treatment with biperiden to control parkinsonian adverse effects. Similar findings were found in another study. ... 

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. 

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