Risperidone dosing

Discuss a risperidone dosing plan and list side effects AG may experience on this medication. 

Usual dose Administer on a once-daily schedule, starting with 2 to 3 mg/day. Adjust dosage at intervals of not less than 24 hours and in dosage increments/decrements of 1 mg/day. Risperidone doses higher than 6 mg/day were not studied. 

In a 6-week open study in 146 Chinese in-patients, risperidone was titrated to 6 mg/day within 7 days 29 patients withdrew prematurely (24). Higher risperidone doses did not appear to have greater efficacy in treating acute schizophrenia and were related to more severe adverse effects. 

Tardive dyskinesia was studied in 330 elderly patients with dementia (mean age 83 years) (94). They were enrolled in a 1-year open study, in which the modal risperidone dose was 0.96 mg/day and the median duration of use was 273 days. The 1-year cumulative incidence of persistent tardive dyskinesia among the 225 patients without dyskinesia at baseline was 2.6%, and patients with dyskinesia at baseline had significant reductions in severity. 

A 30-year-old man with a history of bipolar disorder had substantial weight gain with olanzapine and was switched to risperidone (dose unknown) and lithium carbonate (450 mg bd) (112). A few days later he developed confusion, mild muscle rigidity, a raised temperature, and increased creatine kinase activity. The medications were withdrawn and he responded to supportive therapy. 

Adverse effects leading to dosage reduction or discontinuation were also observed in a retrospective study in 57 patients mean age 84 (range 66-97) years, who took risperidone (doses 0.5-4 mg/day) for more than 1 year (average 2 years) for dementia-related behavioral disturbances (215). Adverse effects included hypotension (n = 4), agitation (n = 6), and sedation (n = 5), and six patients developed a new movement disorder. 

Kontaxakis VP, Havaki-Kontaxaki BJ, Stamouli SS, Christodoulou GN. Optimal risperidone dose in drug-naive, first-episode schizophrenia. Am J Psychiatry 2000 157(7) 1178-9. 

The safety, tolerability, and efficacy of risperidone have been assessed in 103 patients with schizophrenia (52 men and 51 women) aged 65 years or older in an open, multicenter, 12-week study (141). The mean risperidone dose at end-point was 2.4 mg/day. Adverse events occurred in 91 patients and included dizziness (n = 23), insomnia (n = 17), agitation (n = 15), somnolence (n = 15), injury (n = 12), constipation (n = 11), and extrapyramidal disorders (n = 10) 11 patients withdrew because of adverse events. Among the 91 patients with normal baseline QTc intervals (below 450 ms), 9 had a prolonged QTc interval during the study (range 450-516 ms). 

Endocrine A study of 47 boys found that prolactin levels were significantly associated with oral risperidone dose and risperidone and 9-hydroxyrisperidone levels, but not the TaqlA variant in the dopamine D2 receptor gene or variants of the CYP2D6 gene [259 ]. 

Another case of priapism in a 45-year-old male on risperidone and sodium valproate is reported [267 ]. Musculoskeletal A study of risperidone-associated prolactin elevation and markers of bone turnover found that prolactin levels significantly increased and N-telopeptide cross-links (markers of bone resorption) significantly decreased [268 ]. No differences were noted between men and women osteocalcin, N-telopeptide cross-links osteocalcin ratios, oes-tradiol and testosterone did not significantly change and there were no significant associations between risperidone dose and prolactin levels. 

Kent JM, Kushner S, Ning X, Karcher K, Ness S, Aman M, et al. Risperidone dosing in children and adolescents with autistic disorder a double-blind, placebo-controlled study. J Autism Dev Disord 2013 43(8) 1773-83. 

Refai S, Nakama HH. A case of priapism associated with rapid increase in risperidone dose. Prim Care Companion CNS Disord 2012 14(5). 

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