Risperdal (risperidone) and Reglan (metoclopramide) interaction involves which statement?

• A. Reglan decreases Risperdal absorption; avoid for 2 hours
• B. Reglan increases Risperdal absorption
• C. No interaction
• D. They cause chest pain

Answer: (A)

When two drugs affect how much of a dose gets into the bloodstream, it’s often down to how they change the GI tract’s handling of that medication. Metoclopramide speeds up gastric emptying and overall GI transit. If risperidone is given at the same time, this faster movement can shorten the window for risperidone to dissolve and be absorbed, leading to lower blood levels. That’s why separating the doses by a couple of hours helps minimize the interaction, making the statement that Reglan decreases Risperdal absorption—and advising a 2-hour separation—the best choice. If an antiemetic is needed with risperidone, consider alternatives or schedule dosing to avoid this interaction.