Itraconazole is an FDA-approved antifungal for specific systemic and nail fungal infections, prescribed by a provider.
Itraconazole is an FDA-approved oral antifungal medication used to treat specific fungal infections, including certain systemic infections and fungal infections of the toenails or fingernails. It works by interfering with the fungal cell membrane, which stops the fungus from growing. A licensed provider determines whether itraconazole is appropriate based on the type of infection, confirmed if possible with testing, and your overall health.
## How itraconazole works
Itraconazole blocks an enzyme fungi need to build ergosterol, a key component of their cell membranes. Without enough ergosterol, the fungal cell membrane becomes unstable, which stops the fungus from growing and reproducing. This mechanism is specific to fungal cells and is the basis for itraconazole's approved use against several types of fungal infections.
## FDA-approved uses
According to the FDA-approved label, oral itraconazole is indicated for the treatment of the following fungal infections in immunocompromised and non-immunocompromised patients:
- Blastomycosis, pulmonary and extrapulmonary - Histoplasmosis, including chronic cavitary pulmonary disease and disseminated, non-meningeal histoplasmosis - Aspergillosis, pulmonary and extrapulmonary, in patients who are intolerant of or refractory to amphotericin B
Itraconazole is also FDA-approved for the treatment of onychomycosis (fungal nail infection) of the toenail or fingernail, caused by susceptible fungi, in patients without evidence of impaired immune function.
## What to expect during treatment
Itraconazole is taken by mouth, and absorption can be affected by food, stomach acid, and other medications, so your provider will give specific instructions on timing. Treatment courses vary by indication; nail infections typically require a longer course than some systemic infections, but the exact duration and dose are set by your prescriber based on the diagnosis. Blood levels are sometimes checked in more serious systemic infections to confirm adequate drug exposure.
## Safety, interactions, and monitoring
Itraconazole carries an FDA boxed warning regarding negative inotropic effects and should not be used in patients with evidence of ventricular dysfunction, such as congestive heart failure, for the treatment of onychomycosis. It also has significant interactions with many other medications because it affects liver enzymes involved in drug metabolism, so a full medication review is an essential part of any prescribing decision. Liver function may be monitored during longer courses of treatment, and the medication is avoided or used cautiously in people with liver disease.
## Approved indications at a glance
| Indication | Organism type | Typical course length | |---|---|---| | Blastomycosis / histoplasmosis / aspergillosis | Systemic fungal infection | Set by prescriber based on response | | Onychomycosis (toenail) | Nail fungal infection | Longer course, set by prescriber | | Onychomycosis (fingernail) | Nail fungal infection | Shorter course than toenail, set by prescriber |
## How provider-guided access works
A licensed provider will review your symptoms, relevant test results if available, current medications, and heart and liver history before deciding whether itraconazole is an appropriate FDA-approved treatment for you. You can learn about scheduling an evaluation on the [how it works](/how-it-works) page, and review [pricing](/pricing) and [availability](/availability) by state.
## Related questions
### Can itraconazole be taken with food? Itraconazole capsules are generally absorbed better when taken with a full meal, while the oral solution is typically taken on an empty stomach, according to FDA labeling. Because the two formulations are not interchangeable, follow the specific instructions your provider and pharmacist give you for the product you were prescribed.
### What medications interact with itraconazole? Itraconazole affects liver enzymes that metabolize many other drugs, and it is contraindicated with several medications due to the risk of serious interactions. Always give your provider a complete list of prescription drugs, over-the-counter medications, and supplements you take before starting itraconazole.
### Is itraconazole safe for people with heart problems? Itraconazole carries an FDA boxed warning about negative effects on heart muscle contraction and should not be used to treat nail fungal infections in people with a history of heart failure or ventricular dysfunction. Your provider will ask about your cardiac history before prescribing.
### How long does treatment for nail fungus take? Treatment length for onychomycosis depends on whether the fingernails or toenails are affected and how the infection responds, and it is determined by your prescribing provider. Nails grow slowly, so visible improvement can take months even after the treatment course is complete.
## Sources - [DailyMed search: itraconazole](https://dailymed.nlm.nih.gov/dailymed/search.cfm?query=itraconazole) — FDA-approved prescribing information, including boxed warning and approved indications. - [CDC Fungal Diseases](https://www.cdc.gov/fungal/diseases/index.html) — background on fungal infections such as histoplasmosis and blastomycosis. - [MedlinePlus: Itraconazole](https://medlineplus.gov/druginfo/meds/a604031.html) — consumer information on approved uses, precautions, and interactions.