Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with inhibitors of the P-glycoprotein (P-gp) efflux transporter may increase the oral bioavailability of ranolazine, which has been shown in vitro to be a substrate of P-gp. Ranolazine can prolong the QT interval in a dose-dependent manner, thus increased plasma levels may potentiate the risk of ventricular arrhythmias including ventricular fibrillation and torsade de pointes. However, the interaction has not been evaluated in pharmacokinetic studies. Plasma levels of ranolazine (750 mg twice a day) were increased about 2-fold by the CYP450 3A4 and P-gp inhibitor, verapamil (120 mg three times a day), although the extent to which P-gp inhibition actually contributes to the overall interaction is unknown.

MANAGEMENT: Caution is advised if ranolazine is prescribed in combination with P-gp inhibitors. Pharmacologic response to ranolazine should be monitored more closely whenever a P-gp inhibitor is added to or withdrawn from therapy, and the ranolazine dosage adjusted as necessary. Patients should be advised to seek medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, palpitations, or syncope.

You may take ranolazine with or without food, but should try to take it the same way every time. Grapefruit and grapefruit juice should be avoided if possible. Grapefruit juice can increase the levels of ranolazine in your body. High blood levels of food can occasionally cause an irregular heart rhythm that may be serious. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, or fast or pounding heartbeats during treatment with ranolazine. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.