4 known interactions • 2 major • 2 moderate • 0 minor
Always disclose all medications to your healthcare providers — prescription medicines, OTC medications, vitamins, and herbal supplements. This list may not include every possible interaction. Use our Medicine Interaction Checker to screen your complete medication list.
Potentially life-threatening or causing permanent damage. Avoid combination.
May worsen condition or require dose adjustment. Monitor closely.
Usually limited clinical effect. Manage with routine monitoring.
CYP2D6 inhibitors (fluoxetine, paroxetine)
CYP2D6 inhibitors increase risperidone plasma levels (the parent compound is metabolized by CYP2D6). This can increase EPS and other side effects.
Management: Reduce risperidone dose when adding CYP2D6 inhibitor. Monitor for increased side effects.
CYP3A4 inducers (carbamazepine, rifampin, phenytoin)
CYP3A4 inducers increase the clearance of risperidone, potentially causing therapeutic failure. Carbamazepine can double risperidone clearance.
Management: Increase risperidone dose when adding strong CYP3A4 inducer. When inducer is discontinued, reduce dose to avoid toxicity.
Antihypertensives / antihypertensive medicines
Risperidone can enhance hypotensive effect due to alpha-1 blocking properties.
Management: Monitor blood pressure, especially with initiation or dose increases.
CNS depressants (alcohol, benzodiazepines, opioids)
Additive CNS depression. Combination with benzodiazepines may rarely cause respiratory depression (especially IM risperidone).
Management: Avoid concurrent IM risperidone with parenteral benzodiazepines if possible. Monitor closely.
Always ask your pharmacist about potential interactions with food, alcohol, and supplements specific to Risperidone. Some medicines have significant interactions with grapefruit juice, high-fat meals, dairy products, or vitamin K-rich foods.