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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Azole Antifungal [EPC]
Itraconazole is a potent azole antifungal agent used to treat a wide variety of systemic and superficial fungal infections. It works by inhibiting the synthesis of ergosterol, a critical component of fungal cell membranes.
Name
Itraconazole
Raw Name
ITRACONAZOLE
Category
Azole Antifungal [EPC]
Drug Count
4
Variant Count
15
Last Verified
February 17, 2026
RxCUI
311204, 348506, 2106642, 2106648, 833164
UNII
304NUG5GF4
About Itraconazole
Itraconazole is a potent azole antifungal agent used to treat a wide variety of systemic and superficial fungal infections. It works by inhibiting the synthesis of ergosterol, a critical component of fungal cell membranes.
Detailed information about Itraconazole
This page is for informational purposes only and does not replace medical advice. Consult a qualified healthcare professional before using any medication containing Itraconazole.
Healthcare providers typically prescribe Itraconazole for the treatment of systemic fungal infections such as blastomycosis (pulmonary and extrapulmonary), histoplasmosis (including chronic cavitary pulmonary disease and disseminated, non-meningeal histoplasmosis), and aspergillosis (pulmonary and extrapulmonary in patients who are intolerant of or who are refractory to amphotericin B therapy). Beyond these systemic applications, Itraconazole is widely utilized for superficial infections, most notably onychomycosis (fungal infection of the fingernails or toenails) caused by dermatophytes.
At the molecular level, Itraconazole exerts its antifungal effect by disrupting the integrity of the fungal cell membrane. The primary target is the enzyme lanosterol 14-alpha-demethylase, a cytochrome P450-dependent enzyme system. This enzyme is responsible for the conversion of lanosterol to ergosterol. Ergosterol is a vital sterol component of the fungal cell membrane, serving a similar role to cholesterol in human cells.
When Itraconazole binds to the heme iron of the 14-alpha-demethylase enzyme, it inhibits the demethylation process. This leads to two critical consequences for the fungus:
Ultimately, these changes lead to the leakage of essential intracellular components, the inhibition of fungal growth (fungistatic effect), and, in some cases, fungal cell death (fungicidal effect). Notably, Itraconazole has a much higher affinity for fungal cytochrome P450 enzymes than for human cytochrome P450 enzymes, which provides its therapeutic selectivity, although significant human enzyme inhibition still occurs, leading to numerous drug interactions.
The pharmacokinetics of Itraconazole are complex and vary significantly between the different oral formulations (capsules versus oral solution).
Itraconazole is highly lipophilic (fat-soluble) and exhibits extensive protein binding, primarily to albumin (approximately 99.8%). It distributes widely into tissues such as the liver, kidneys, and adipose tissue. Concentrations in keratinous tissues, particularly the skin and nails, can be up to four times higher than in plasma and persist for weeks after the drug is discontinued. However, penetration into the cerebrospinal fluid (CSF) is negligible.
Itraconazole is extensively metabolized in the liver by the Cytochrome P450 3A4 (CYP3A4) isoenzyme system. The primary metabolite is hydroxy-itraconazole, which possesses antifungal activity comparable to the parent drug. Because Itraconazole is both a substrate and a potent inhibitor of CYP3A4, it is associated with a high risk of drug-drug interactions.
Itraconazole is FDA-approved for several specific fungal conditions:
Off-label uses may include the treatment of sporotrichosis, certain types of chromomycosis, and prophylaxis against fungal infections in immunocompromised patients, such as those with neutropenia or HIV/AIDS.
Itraconazole is available in several formulations to accommodate different clinical needs:
> Important: Only your healthcare provider can determine if Itraconazole is right for your specific condition. The choice of formulation depends heavily on the type of infection and the patient's ability to absorb the medication.
Dosage for Itraconazole varies significantly based on the indication and the formulation used. Healthcare providers typically follow these standard guidelines:
The safety and efficacy of Itraconazole in pediatric patients have not been firmly established. While healthcare providers may occasionally use Itraconazole in children for life-threatening systemic infections where other options are limited, there is no standard FDA-approved pediatric dose. Use in children requires extreme caution and a careful risk-benefit analysis by a specialist.
For patients with renal (kidney) impairment, the oral capsules generally do not require dose adjustments. However, the intravenous formulation contains hydroxypropyl-β-cyclodextrin, which can accumulate in patients with a creatinine clearance of less than 30 mL/min; therefore, the IV form should be avoided in these patients. The oral solution should also be used with caution in severe renal impairment.
Itraconazole is primarily metabolized in the liver. Patients with hepatic (liver) cirrhosis should be monitored closely. While specific dose reduction formulas are not standardized, healthcare providers may adjust the dose based on the patient's liver function tests and clinical response.
Clinical studies did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function.
Proper administration is critical to ensure the drug reaches therapeutic levels in the blood:
If you miss a dose, take it as soon as you remember. If it is almost time for your next scheduled dose, skip the missed dose and resume your regular schedule. Do not double the dose to catch up. Consistent levels of the drug in the body are necessary to fight the infection effectively.
In the event of an overdose, seek emergency medical attention or contact a Poison Control Center immediately. Symptoms of overdose are not well-documented but may include severe nausea, abdominal pain, or an exacerbation of side effects. Itraconazole is not removed by hemodialysis.
> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose or stop taking the medication without medical guidance, even if you feel better, as the infection may return.
Most patients tolerate Itraconazole well, but some may experience mild to moderate side effects. Common reactions include:
> Warning: Stop taking Itraconazole and call your doctor immediately or seek emergency care if you experience any of the following:
Prolonged use of Itraconazole (months to years) requires careful monitoring. Long-term risks include chronic liver enzyme elevation, potential adrenal suppression (though rare with Itraconazole compared to other azoles), and the development of peripheral neuropathy. Regular blood tests are essential for those on long-term therapy.
Itraconazole carries two significant FDA Black Box Warnings:
Report any unusual symptoms to your healthcare provider immediately to ensure your safety during treatment.
Itraconazole is a powerful medication that requires strict adherence to safety protocols. It is essential to disclose your full medical history, including any history of heart disease, liver disease, or kidney problems, to your healthcare provider before starting therapy.
As noted by the FDA, Itraconazole must be used with extreme caution due to two major risks:
Patients with a known hypersensitivity to other 'azole' antifungals (such as fluconazole or ketoconazole) may also be allergic to Itraconazole. Signs of a severe reaction include angioedema (deep tissue swelling) and respiratory distress.
Itraconazole has been linked to rare but serious liver injury. This can occur even in patients without pre-existing liver disease. Treatment should be stopped immediately if clinical signs of hepatitis develop.
Beyond CHF, Itraconazole can contribute to QT prolongation, especially when combined with other medications that affect the heart's electrical activity. This increases the risk of ventricular arrhythmias.
If you experience numbness, tingling, or weakness in your extremities, notify your doctor. Peripheral neuropathy has been reported and may be irreversible if the drug is continued.
Patients on Itraconazole, especially for extended periods, require regular clinical monitoring:
Itraconazole may cause dizziness or visual disturbances in some patients. If you experience these side effects, you should avoid driving or operating heavy machinery until the symptoms resolve.
Alcohol should be avoided or strictly limited while taking Itraconazole. Both alcohol and Itraconazole are processed by the liver; combining them can increase the risk of hepatotoxicity. Furthermore, alcohol can exacerbate gastrointestinal side effects like nausea and vomiting.
Do not stop taking Itraconazole abruptly unless directed by a doctor due to a serious side effect. For fungal infections, stopping the medication too early can allow the fungus to continue growing, leading to a relapse of the infection. There is no known withdrawal syndrome, but the infection risk is the primary concern.
> Important: Discuss all your medical conditions and all other medications with your healthcare provider before starting Itraconazole.
The following drugs must NEVER be taken with Itraconazole due to the risk of life-threatening interactions:
Itraconazole does not typically interfere with standard laboratory tests, but its effect on liver enzymes and potassium must be interpreted in the context of the medication's known side effects.
Most interactions occur because Itraconazole is a potent inhibitor of the CYP3A4 enzyme. By 'clogging' this enzyme, Itraconazole prevents the liver from breaking down other drugs, causing them to reach dangerous levels. Additionally, Itraconazole inhibits P-glycoprotein (P-gp), a transporter protein that pumps drugs out of cells, further increasing the systemic exposure of various medications.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking. A comprehensive review of your 'medication list' is the best way to prevent dangerous interactions.
Itraconazole must NEVER be used in the following circumstances:
In these situations, healthcare providers will perform a careful risk-benefit analysis:
There is potential for cross-sensitivity between Itraconazole and other azole antifungal agents (e.g., fluconazole, voriconazole, ketoconazole). If you have had a severe allergic reaction to one azole, you are at a higher risk for a reaction to Itraconazole. Always inform your provider of previous drug allergies.
> Important: Your healthcare provider will evaluate your complete medical history and current medications before prescribing Itraconazole to ensure it is safe for you.
Itraconazole is generally avoided during pregnancy. According to the FDA, it should only be used for systemic, life-threatening fungal infections if the potential benefit justifies the potential risk to the fetus.
Itraconazole is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. Most clinical guidelines suggest avoiding breastfeeding while taking this medication.
Itraconazole is not FDA-approved for use in children. The risks of long-term use on bone growth and development are not well-characterized. In rare cases where it is used off-label for systemic infections, the dose must be carefully calculated by a pediatric infectious disease specialist.
Elderly patients are at a higher risk for several Itraconazole-related complications:
Since the liver is the primary site of metabolism, patients with cirrhosis or hepatitis require close monitoring. The half-life of the drug is prolonged in these patients. If liver function tests (LFTs) become significantly elevated (more than twice the upper limit of normal), healthcare providers will typically discontinue the drug.
> Important: Special populations require individualized medical assessment and more frequent monitoring than the general population.
Itraconazole is a highly selective inhibitor of fungal cytochrome P450 enzymes. Its primary mechanism involves the inhibition of 14-alpha-demethylase, which is responsible for converting lanosterol into ergosterol. The resulting depletion of ergosterol and accumulation of methylated sterol precursors disrupt the fungal cell membrane's fluid dynamics and the function of membrane-bound enzymes. This leads to a cessation of fungal growth (fungistasis) or cell lysis.
The antifungal activity of Itraconazole is concentration-dependent for some species and time-dependent for others. It exhibits a significant post-antifungal effect (PAFE), meaning fungal growth remains suppressed even after drug levels drop below the minimum inhibitory concentration (MIC). It does not have significant activity against Zygomycetes (like Mucor) but is highly effective against Candida species, Aspergillus, and endemic fungi.
| Parameter | Value |
|---|---|
| Bioavailability | ~55% (Capsules with food), >90% (Solution) |
| Protein Binding | 99.8% (Mainly to albumin) |
| Half-life | 21 hours (Single dose), 64 hours (Steady state) |
| Tmax | 2 to 5 hours |
| Metabolism | Hepatic (Extensively via CYP3A4) |
| Excretion | Renal (35% as metabolites), Fecal (54%) |
Itraconazole is classified as a Triazole Antifungal. It is part of the broader 'Azole' class, which includes imidazoles (like ketoconazole) and other triazoles (like fluconazole and voriconazole). Triazoles generally have a higher specificity for fungal enzymes and fewer side effects related to human steroid synthesis than older imidazoles.
Medications containing this ingredient
Common questions about Itraconazole
Itraconazole is a broad-spectrum antifungal medication used to treat various infections caused by fungi. It is FDA-approved for systemic infections like histoplasmosis, blastomycosis, and aspergillosis, which can affect the lungs and other organs. Additionally, it is commonly used to treat fungal nail infections (onychomycosis) and yeast infections of the mouth and throat (thrush). Because it is a potent medication, it is usually reserved for infections that are severe or have not responded to other treatments. Your doctor will determine the appropriate use based on the specific type of fungus causing your illness.
The most frequently reported side effects of Itraconazole include gastrointestinal issues such as nausea, vomiting, diarrhea, and abdominal pain. Patients also commonly report headaches, dizziness, and mild skin rashes. While these are often manageable, some people may experience swelling in the limbs (edema) or fatigue. It is important to monitor how you feel during the first few weeks of treatment, as many of these side effects occur early on. If any of these symptoms become severe or persistent, you should consult your healthcare provider for guidance.
It is generally recommended to avoid or significantly limit alcohol consumption while taking Itraconazole. Both alcohol and Itraconazole are processed by the liver, and combining them can place excessive stress on this organ, increasing the risk of liver damage (hepatotoxicity). Furthermore, alcohol can worsen common side effects of the medication, such as dizziness, nausea, and stomach upset. Since Itraconazole carries a warning for potential liver injury, maintaining liver health is a priority during treatment. Always discuss your alcohol intake habits with your doctor before starting this antifungal.
Itraconazole is generally not recommended during pregnancy unless the infection is life-threatening and no safer alternatives exist. Animal studies have indicated that high doses of the drug can cause developmental harm to the fetus. For non-serious infections like nail fungus, treatment should be postponed until after pregnancy. Women of childbearing age should use effective birth control while taking the medication and for at least two months after the final dose. If you become pregnant while taking Itraconazole, notify your healthcare provider immediately to discuss the risks.
The time it takes for Itraconazole to work depends on the type and severity of the infection being treated. For oral thrush, symptoms may begin to improve within a few days. However, for systemic infections like histoplasmosis, it may take several weeks of consistent dosing before significant clinical improvement is noted. In the case of fungal nail infections, the drug must accumulate in the nail bed; while the fungus may be killed within a few months, a healthy-looking nail may not fully grow in for 6 to 12 months. It is vital to complete the full course of therapy as prescribed.
You should not stop taking Itraconazole suddenly without consulting your doctor, even if your symptoms have disappeared. Fungal infections can be stubborn, and stopping the medication prematurely can allow the remaining fungi to multiply, leading to a relapse or the development of antifungal resistance. The only exception is if you experience a serious allergic reaction or signs of liver or heart failure, in which case you should seek immediate medical help. Always follow the specific duration of treatment outlined by your healthcare professional to ensure the infection is fully eradicated.
If you miss a dose of Itraconazole, take it as soon as you remember. However, if it is nearly time for your next scheduled dose, skip the missed one and continue with your regular dosing schedule. Do not take two doses at once to make up for a missed one, as this can increase the risk of side effects. Maintaining a consistent level of the medication in your bloodstream is important for effectively fighting the fungal infection. Setting a daily alarm can help you remember to take the medication at the same time each day.
Weight gain is not a typical direct side effect of Itraconazole; however, sudden weight gain can be a sign of a very serious complication called congestive heart failure (CHF). Itraconazole can cause the body to retain fluid, which may manifest as rapid weight gain, swelling in the ankles or feet, and shortness of breath. If you notice an unexplained and quick increase in weight while taking this medication, you must contact your doctor immediately. This is different from gradual weight gain related to diet or lifestyle and requires urgent medical evaluation.
Itraconazole has a very high potential for drug interactions because it inhibits the CYP3A4 enzyme, which breaks down many other drugs. Taking it with certain medications—such as some statins, blood thinners, or heart rhythm drugs—can lead to dangerous levels of those medications in your system. This can result in serious heart problems or muscle damage. You must provide your doctor and pharmacist with a complete list of all prescription drugs, over-the-counter medicines, and herbal supplements you are taking. They will check for 'contraindicated' combinations that could be life-threatening.
Yes, Itraconazole is available as a generic medication in both capsule and oral solution forms. Generic versions are typically more cost-effective than the brand-name Sporanox while containing the same active ingredient and meeting the same FDA standards for quality and bioequivalence. However, keep in mind that different formulations (like the SUBA-itraconazole) may not have direct generic equivalents and are not interchangeable with standard generic capsules. Always check with your pharmacist to ensure you are receiving the specific formulation prescribed by your healthcare provider.