Use of therapeutic drug monitoring of risperidone microspheres long-acting injection in hemodialysis: A case report

Limited evidence exists for the use of psychiatric medications in patients with end-stage renal disease on hemodialysis. Many psychotropic medications are not well-studied in this population, and optimal dosing of these medications is not well-established. Therapeutic drug monitoring is a useful tool in assessing the safety and efficacy of psychotropic medications; however, the use is unclear with long-acting injectable antipsychotics. We present a case of a 73-year-old male initiated on hemodialysis while on risperidone microspheres long-acting injection (RMLAI). Risperidone and 9-hydroxyrisperidone plasma concentrations obtained from this patient were relatively similar before and after initiation of hemodialysis, therefore it appears hemodialysis does not significantly influence clearance of RMLAI. Plasma concentrations in this patient were higher than those reported in the literature for equivalent doses, which may indicate accumulation of the medication secondary to renal impairment.