Answer
Grapefruit can increase verapamil concentrations and make adverse effects such as dizziness, low blood pressure or bradycardia more likely.
Sources for this answer
- NHSNHS · NHS medicine guidance
- Verapress MR 240 tablets — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.