Take this medication by mouth with a glass of water. Follow the directions on the prescription label. Take this medication with food. Take your medication at regular intervals. Do not take your medication more often than directed. Do not stop taking except on your care team's advice. Talk to your care team about the use of this medication in children. While this medication may be prescribed for children as young as 10 years of age for selected conditions, precautions do apply.

Side effects that you should report to your care team as soon as possible:

• Allergic reactions-skin rash, itching, hives, swelling of the face, lips, tongue, or throat
• High lactic acid level-muscle pain or cramps, stomach pain, trouble breathing, general discomfort or fatigue
• Low vitamin B12 level-pain, tingling, or numbness in the hands or feet, muscle weakness, dizziness, confusion, difficulty concentrating Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
• Diarrhea
• Gas
• Headache
• Metallic taste in mouth
• Nausea

Our pharmacists will check to see if this medication will cause any interactions with the information in your profile.

Do not take this medication with any of the following:

• Certain contrast medications given before X-rays, CT scans, MRI, or other procedures
• Dofetilide This medication may also interact with the following:
• Acetazolamide
• Alcohol
• Certain antivirals for HIV or hepatitis
• Certain medications for blood pressure, heart disease, irregular heart beat
• Cimetidine
• Dichlorphenamide
• Digoxin
• Diuretics
• Estrogens, progestins, or birth control pills
• Glycopyrrolate
• Isoniazid
• Lamotrigine
• Memantine
• Methazolamide
• Metoclopramide
• Midodrine
• Niacin
• Phenothiazines like chlorpromazine, mesoridazine, prochlorperazine, thioridazine
• Phenytoin
• Ranolazine
• Steroid medications like prednisone or cortisone
• Stimulant medications for attention disorders, weight loss, or to stay awake
• Thyroid medications
• Topiramate
• Trospium
• Vandetanib
• Zonisamide