Common side effects of ranolazine (Ranexa) include: headaches, nausea, dizziness and constipation. These generally do not require a doctor's visit unless they become severe. More serious side effects include: fainting, labored breathing and any problems with your heartbeat. If you are taking Ranexa and experience these or other worrisome side effects, you should see a doctor as soon as possible.
Allergic reactions from Ranexa are also possible. Signs of allergic reaction include: swelling, rash, itching, chest tightness or pain, hoarseness, blood in the urine or a different amount of urine, blurred vision, confusion, diminished touch, fainting, fever, chills, sore throat, change in heartbeat, numbness, burning, prickling, ringing in the ears, severe dizziness, weakness, shortness of breath or bruising or bleeding. If you experience these signs of an allergic reaction, get immediate medical help.