Itraconazole Dosage Guide: What You Need to Know

If you’ve been prescribed itraconazole, you probably wonder how much you should take and why the dose changes for different bugs. Below you’ll find the most common dosing schedules, the reasons doctors might adjust them, and safety tips you can use right away.

Standard Dosing for Common Fungal Infections

For most skin infections (like tinea corporis or nail fungus), the usual adult dose is 200 mg once daily. Some doctors split that into 100 mg twice a day to keep blood levels steady.

When treating more serious infections such as blastomycosis, histoplasmosis, or severe yeast infections, the dose often doubles to 400 mg per day, either as 200 mg twice daily or 400 mg once daily. Therapy usually lasts 6–12 weeks, depending on how the infection responds.

For oral thrush or esophageal candidiasis, doctors commonly start with 200 mg twice daily for the first 3 days, then drop to 200 mg once daily for the rest of the course.

Children get lower doses based on weight—about 5 mg per kilogram of body weight per day, split into two doses. Always check the exact prescription, because dosing can vary by brand (capsule vs. solution).

Factors That Change Your Dose

Several things can push the doctor to change the standard amount. If you have liver problems, the dose may be cut in half because itraconazole is processed in the liver. Your doctor might also order a blood test (called a trough level) to see how much drug is actually in your bloodstream. If the level is low, they could increase the dose; if it’s high, they’ll lower it.

Medications that affect stomach acidity, like antacids or proton‑pump inhibitors, can reduce how much itraconazole your body absorbs. In those cases, doctors may recommend taking the drug on an empty stomach or switching to a different formulation.

Drug interactions matter too. Some medicines (like certain heart drugs or HIV meds) can raise itraconazole levels and cause side effects, while others (like some anticonvulsants) can pull the drug out of your system faster. Always list every prescription and over‑the‑counter product you’re using.

Weight changes also play a role. If you gain or lose a lot of weight during treatment, your doctor might adjust the dose to keep the blood level in the right range.

Lastly, the type of fungus matters. Some rare molds need higher doses for a longer period, while straightforward yeast infections often clear up with the standard schedule.

Bottom line: follow the exact instructions on your bottle, take the drug with or without food as your doctor says, and keep any follow‑up appointments for blood tests. If you feel dizzy, have a fast heartbeat, or notice severe stomach pain, call your pharmacist or doctor right away.

Remember, itraconazole works best when you finish the full course, even if you feel better early on. Cutting treatment short can let the fungus come back and become harder to treat.

Got more questions? Write them down before your next appointment and ask your health provider how the dose fits your specific situation. Staying informed helps you get the best result from your antifungal therapy.