Ringworm, despite its name, is not a worm but a fungal infection that can occur anywhere on the skin. Ringworm is highly contagious and can be difficult to treat. Physicians will commonly attempt to first treat with topical medications. When ringworm does not respond to topical treatments, oral antifungal medications represent the next line of treatment.
Itraconazole
Itraconazole is commonly prescribed to treat ringworm that occurs in the finger or toe nails. Itraconazole comes as a capsule and a liquid that people take by mouth. When used for ringworm of the nails, people will take itraconazole for twice a day for seven days, not at all for seven days and then twice a day for an additional seven days, according to the National Institutes of Health. Itraconazole can cause diarrhea, constipation, gas, heartburn, headache, dizziness, muscle pain, mouth sores, bleeding gums and depression.
It is possible for patients to experience serious side effects such as nausea, vomiting, fatigue, itching, rash and yellowing of the skin and eyes. Itraconazole has also been shown to cause congestive heart failure, a condition in which the heart cannot pump enough blood throughout the body.
Fluconazole
Fluconazole is commonly used to treat fungal infections of the genital area such as genital ringworm, often referred to as jock itch. MayoClinic.com explains that physicians commonly prescribe fluconazole up to 400 mg per day and the length of treatment depends on the severity of the illness. Side effects of fluconazole are rare but can include abdominal pain, chills, cough, dark urine, dizziness, fast heart rate, fever, fatigue, diarrhea and difficulty swallowing.
Ketoconazole
Physicians commonly prescribe ketoconazole to treat ringworm of the feet, commonly known as tinea pedis or athlete's foot. Physicians commonly prescribe 200 mg once a day, according to MayoClinic.com. Side effects of ketoconazole are rare but can include back or stomach pain, bleeding gums, blurred vision, change in color vision and numbness or tingling.
Terbinafine
Terbinafine is an oral antifungal antibiotic that is commonly used to treat all forms of ringworm. MayoClinic.com states that physicians commonly prescribe a dosage of 250 mg once a day, and the length of treatment depends on the type of ringworm being treated. The most common side effect of terbinafine is fever, but people may experience body aches, cough, chills, diarrhea, difficulty breathing, ear congestion and a general feeling of discomfort.
