Itraconazole: Indications for Use, Dosing & Side Effects

Itraconazole is an antifungal medication used to treat fungal infections such as histoplasmosis, blastomycosis, and aspergillosis. It works by stopping the growth and spread of fungi, helping eliminate infections that can affect the lungs, nails, or skin.

In the United States, itraconazole is available by prescription only and comes in different forms, including capsules, tablets, and oral solution. The most common brand names are Sporanox, Onmel, and Tolsura, as well as generic versions. Each form may be approved for specific uses and has its own dosing recommendations.

Because itraconazole can affect liver function, it should always be taken under medical supervision. A healthcare provider will determine the appropriate dose and duration of treatment based on the infection being treated. Regular check-ups and liver function tests are recommended, especially when the medication is used for extended periods.

Indications for use

Itraconazole is approved by the FDA for the treatment of:

• Blastomycosis (pulmonary and extrapulmonary);

• Histoplasmosis (pulmonary and disseminated, including chronic cavitary pulmonary disease);

• Aspergillosis, in patients who are intolerant of or refractory to amphotericin B;

• Onychomycosis (fungal infection of the fingernails or toenails caused by dermatophytes).

It is also approved for the treatment of oropharyngeal and esophageal candidiasis in oral solution form only.

Off-label uses (not FDA-approved)

Itraconazole may also be prescribed off-label for:

• Vaginal candidiasis;

• Skin infections such as tinea corporis, tinea cruris, tinea pedis, or pityriasis versicolor;

• Fungal keratitis (eye infection).

These off-label uses should only be considered under medical supervision, typically when other antifungal treatments are not effective or appropriate.

Dosing instructions

Itraconazole should be taken by mouth with a full glass of water, preferably after a meal to improve absorption and reduce stomach irritation.

The dosage of itraconazole for adults varies according to the condition being treated and includes:

Off-label dosing examples (for reference only)

Off-label regimens sometimes used in clinical practice include:

• Vaginal candidiasis: 200 mg twice daily for 1 day or once daily for 3 days;

• Tinea infections (skin): 100–200 mg once daily for 7–15 days;

• Fungal keratitis: 200 mg once daily for about 21 days.

Because these are not FDA-approved indications, dosing must be individualized and prescribed only by a qualified healthcare provider.

Side effects

Common side effects of itraconazole include headache, nausea, vomiting, stomach pain, diarrhea, constipation, swelling, unpleasant taste in the mouth, and muscle or joint pain. Some people may also experience menstrual irregularities or erectile dysfunction.

Itraconazole can occasionally cause serious liver or pancreatic problems. Stop taking the medication and seek immediate medical attention if you experience severe nausea, vomiting, abdominal pain, yellowing of the skin or eyes (jaundice), dark urine, or pale stools. These symptoms may indicate liver damage or pancreatitis.

In rare cases, itraconazole may cause allergic reactions or heart problems such as congestive heart failure. Get medical help right away if you notice shortness of breath, swelling in the legs or feet, unusual fatigue, rapid heartbeat, or signs of a severe allergic reaction like rash, itching, or swelling of the face and throat.

Contraindications for use

Itraconazole should not be used by people with a history of congestive heart failure or those who are allergic to itraconazole or other azole antifungal medications, such as fluconazole, ketoconazole, clotrimazole, or voriconazole. It should also be avoided in people with liver disease unless the potential benefits clearly outweigh the risks.

Women who are pregnant, breastfeeding, or trying to become pregnant should not use itraconazole unless absolutely necessary and prescribed by a healthcare professional. Women of childbearing age should use effective contraception during treatment and for at least two months after the last dose to prevent pregnancy.

Itraconazole can interact with many medications, including certain statins, anticoagulants, and acid-reducing drugs. It is important to tell your healthcare provider about all medicines, supplements, and vitamins you are taking to avoid harmful drug interactions.