Drug Interaction Report

MONITOR: The coadministration of risperidone with serdexmethylphenidate, dexmethylphenidate, or methylphenidate, when there is an increase or decrease of dosage of either medication, may increase the risk of extrapyramidal symptoms. The mechanism of this interaction has not been delineated.

MANAGEMENT: Caution is advised if risperidone must be used concomitantly with methylphenidate, dexmethylphenidate, or serdexmethylphenidate. Patients should be monitored more closely whenever either drug is added to or withdrawn from therapy and whenever either dosage is changed. Patients should be monitored for the development of extrapyramidal symptoms (e.g., tremor, shuffling gait, drooling, mask-like face, tongue stiffness, muscle spasms or rigidity, involuntary movements) and changes in mental status.

GENERALLY AVOID: Risperidone oral solution is not compatible with either tea or cola. In addition, alcohol may potentiate some of the pharmacologic effects of risperidone. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Risperidone oral solution should not be mixed with tea or cola. It may be taken with water, coffee, orange juice, or lowfat milk. Patients should also be advised to avoid consumption of alcohol.