How the interaction occurs:
Ranolazine may increase how much metformin your body absorbs.
What might happen:
The effects of metformin may increase and cause your blood sugar to become too low or may cause a serious condition called lactic acidosis.Symptoms of low blood sugar include chills, cold sweat, dizziness, drowsiness, shaking, rapid heartbeat, weakness, headache, fainting, tingling of the hands or feet, or hunger.Symptoms of lactic acidosis include feeling very weak, tired, or uncomfortable, unusual muscle pain, trouble breathing, unusual or unexpected stomach discomfort, feeling cold, dizziness or lightheadedness, suddenly developing a slow or irregular heartbeat.
What you should do about this interaction:
Let your healthcare professionals (e.g doctor or pharmacist) know that you are taking these medicines together. Your doctor may want you to check your blood sugar more often while taking them together. Your doctor may want to adjust the dosage of your metformin while you are taking ranolazine or if you stop taking ranolazine.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.Reference:1.Ranexa (ranolazine) US prescribing information. CV Therapeutics, Inc. December, 2013.