Before you decide to take an oral antifungal medication to treat a fungal infection such as athlete's foot or a fungal nail infection, you and your health professional will want to consider the possible risks. Depending on the medication and your particular risk factors, some antifungal medications may:

• Affect liver or kidney function.
• Cause liver damage or failure, particularly when combined with alcohol or certain medications.
• Weaken the heart's ability to contract, leading to heart failure.¹
• Cause dangerous side effects when combined with many different common medications.

During oral antifungal treatment, your health professional may require blood tests to check your kidney and liver function.

Possible mild side effects caused by antifungal medications include stomach upset, headaches, and skin rash.