Before taking this medication, it is best to advise your doctor if you are allergic Ketoconazole; or to other azole antifungal drugs (such as fluconazole, itraconazole); or to any other medications or allergies in general. This product may contain inactive ingredients, which can cause allergic reactions or other problems.
Before taking this medication, it is for the best to inform your doctor of your Medical history. Especially if you have had any of the following; liver problems, alcohol use, low testosterone levels, decreased adrenal gland function problems (such as low cortisol levels, Addison's disease, adrenal insufficiency), little or no stomach acid production (achlorhydria).
Ketoconazole may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.
The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using ketoconazole, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).
Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using ketoconazole safely.