Before taking dofetilide,
tell your doctor and pharmacist if you are allergic to dofetilide, any other medications, or any of the ingredients in dofetilide capsules. Ask your pharmacist or check the manufacturer's patient information for a list of the ingredients.
tell your doctor if you are taking cimetidine (Tagamet), dolutegravir (Tivicay), hydrochlorothiazide (Microzide, Oretic), hydrochlorothiazide and triamterene (Dyazide, Maxzide), ketoconazole (Nizoral), megestrol (Megace), prochlorperazine (Compro, Procomp), trimethoprim (Primsol), trimethoprim and sulfamethoxazole (Bactrim, Septra, Sulfatrim), and verapamil (Calan, Covera, Verelan). Your doctor will probably tell you not to take dofetilide if you are taking one or more of these medications.
tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: amiloride (Midamor); antibiotics such as erythromycin (E.E.S., E-Mycin) and norfloxacin (Noroxin); certain antifungal medications such as fluconazole (Diflucan), itraconazole (Sporanox), and ketoconazole (Nizoral); bepridil (Vascor); cannabinoids such as dronabinol (Marinol), nabilone (Cesamet) or marijuana (cannabis); digoxin (Lanoxin); diltiazem (Cardizem, Cartia XT, Dilacor XR, Taxtia XT, Tiazac); diuretics ('water pills'); HIV protease inhibitors including atazanavir (Reyataz), darunavir (Prezista), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir, in Kaletra), saquinavir (Invirase) and tipranavir (Aptivus); medications for asthma such as zafirlukast (Accolate); medications for depression, mental illness, or nausea; medications for irregular heart beats such as amiodarone (Cordarone, Pacerone); metformin (Fortamet, Glucophage, Glumetza, Riomet); nefazodone;or quinine (Qualquin).
tell your doctor if you have or have ever had long QT syndrome (condition that increases the risk of developing an irregular heartbeat that may cause fainting or sudden death), or kidney disease.
tell your doctor if you have excessive diarrhea, sweating, vomiting, loss of appetite, or decreased thirst or a low level of potassium in your blood, and if you have or have ever had have heart or liver disease.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking dofetilide, call your doctor.