As directed by your doctor, take this medication by mouth twice daily with food (once in the morning and once at night). Take this medication with caution if your doctor or pharmacist says you can eat grapefruit or drink grapefruit juice while using it. If you are taking this medicine with grapefruit, you may experience side effects. You can find out more from your doctor or pharmacist. Regular use of this medication will make it more effective for you. Make sure you take it at the same time each day to help you remember to take it. Multaq should not be stopped without your doctor's approval. Do not stop taking this medication if you feel well. In order to lower your chances of getting serious blood clots, your doctor may also prescribe another medication ("blood thinner"/anticoagulant). It is important to follow the instructions provided by your doctor. Do not hesitate to ask your doctor or pharmacist any questions about your medications. If your heartbeat or pulse becomes fast or irregular, seek medical attention immediately. When talking to our doctor about Multaq, advise them if you have a personal or family history of worsening heart failure.