Patients generally should not use systemic antifungal agents if they have been diagnosed with kidney disease or liver disease, as some antifungals can cause damage to these organs in rare cases. Patients should also be honest with their physician regarding their present and past use of alcohol. 

In addition, patients with a history of heart failure should not take these drugs, as some antifungals have been shown to weaken heart contractions. Patients with a history of reacting to antifungal agents should also avoid these medications.

Therapy with topical antifungals typically causes very few side effects. In some cases, patients may experience the following:

• Burning
  
• Skin rash
  
• Itchiness (pruritus)
  
• Eczema (skin appears very dry, thickened or scaly)
  
• Allergic dermatitis at application site
  
• Minor pain upon application

Systemic antifungals are more likely to cause side effects than topical antifungals. These side effects may include the following:

• Headache
  
• Gastrointestinal symptoms (e.g., heartburn, diarrhea, dyspepsia, flatulence, abdominal pain, nausea)
  
• Skin rash
  
• Itching
  
• Hives (pink or white bumps that appear on or beneath the skin)
  
• Thirst
  
• Dizziness or faintness
  
• Visual disturbances
  
• Taste disturbances

Patients experiencing any of these side effects should consult their dermatologist.  

To help minimize the risk of some side effects, most systemic antifungals should be taken with food.

In more serious cases, systemic antifungals can cause damage to the liver, kidneys or heart. Decreases in white blood cell count have also been reported (particularly in patients with a weakened immune system). As a result, some antifungal treatments (e.g., itraconazole, terbinafine, fluconazole) may require patient monitoring through blood tests. When properly monitored, these treatments are considered very safe.

Patients should contact their physician immediately if any of the following symptoms develop:

• Fever
• Unusual bruising or bleeding
• Sore throat
• Soreness or irritation of the mouth
• Urine dark in color
• Stools pale in color
• Extreme fatigue or weakness
• Jaundice (yellowing of the eyes and skin)
• Decreased interest in food
• Seizures
• Swelling (e.g., face, throat, tongue, lips, hands, feet)
• Breathing and/or swallowing difficulty