A 34-year-old man with moderate intellectual disability and limited verbal communication is referred by his group home for aggressive outbursts. Staff reports that the behavior has escalated over the past three weeks. His current medications include risperidone 2 mg BID (started 2 years ago for aggression) and valproic acid 500 mg BID. The PMHNP evaluates the patient and reviews his medication regimen. Which of the following reflects the most appropriate prescribing approach for this patient?