Itraconazol Viatris (Itraconazole)

Itraconazole is used to treat systemic fungal infections by targeting the fungal cell membrane synthesis pathway.

• Invasive aspergillosis: eradicates the pathogen and prevents disease progression.
• Blastomycosis: eliminates the causative organism and resolves pulmonary and disseminated disease.
• Histoplasmosis: clears infection in acute and chronic forms.
• Systemic candidiasis: treats bloodstream and deep‑tissue Candida infections.
• Sporotrichosis: resolves cutaneous and disseminated disease caused by Sporothrix species.

• Itraconazole inhibits the fungal enzyme lanosterol 14α‑demethylase, a key step in ergosterol synthesis. By blocking ergosterol production, the drug disrupts the integrity of the fungal cell membrane, leading to increased permeability and ultimately fungal cell death. This mechanism is selective for fungi, sparing human cells that use cholesterol instead of ergosterol.

Adverse reactions may range from mild to severe and should be monitored during therapy.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Headache: transient cranial discomfort.
• Rash: skin erythema or pruritus.
• Elevated liver enzymes: mild hepatic enzyme changes.
• Diarrhea: loose stools without blood.
• Dyspepsia: indigestion or upper abdominal discomfort.

Serious or Rare Side Effects

• Hepatotoxicity: significant liver injury requiring monitoring.
• Congestive heart failure: worsening of pre‑existing cardiac conditions.
• Severe skin reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Visual disturbances: blurred vision or photophobia.
• Hemorrhagic events: rare bleeding tendencies.
• Anaphylaxis: acute allergic reaction requiring emergency care.

Before initiating therapy, clinicians should assess patient history and monitor relevant parameters.

• Liver function: evaluate baseline hepatic enzymes and monitor periodically.
• Cardiac status: avoid in patients with uncontrolled heart failure.
• Drug interactions: review concomitant medications for CYP3A4 substrates.
• Pregnancy: assess risk‑benefit ratio; limited data available.
• Breastfeeding: consider potential excretion in milk.
• Storage: Store below 25°C: keep in the original container, protect from moisture and direct sunlight.

Itraconazole has a high potential for pharmacokinetic interactions due to CYP3A4 inhibition.

Major Interactions (Avoid)

• Rifampin: markedly reduces itraconazole exposure.
• St. John’s wort: induces metabolism, lowering efficacy.
• Certain antiretrovirals (e.g., protease inhibitors): may cause toxicity.
• Some statins (e.g., simvastatin): increased risk of myopathy.
• Quinidine: elevated plasma levels leading to arrhythmias.

Moderate Interactions (Monitor Closely)

• Warfarin: may enhance anticoagulant effect, monitor INR.
• Phenytoin: may decrease itraconazole levels.
• Ketoconazole: additive hepatotoxicity risk.
• Calcium channel blockers: possible increased concentrations.
• Oral contraceptives: reduced effectiveness, advise alternative contraception.