Itraconazole Eg (Itraconazole)

Itraconazole is an azole antifungal used to treat infections caused by susceptible fungi across several disease categories.

• Dermatophytosis: effective in clearing skin fungal infections and relieving associated symptoms.
• Onychomycosis: promotes regrowth of healthy nail tissue by eradicating nail bed fungus.
• Blastomycosis: treats systemic blastomyces infection, reducing pulmonary and disseminated disease.
• Histoplasmosis: controls disseminated histoplasma infection, especially in immunocompromised patients.
• Aspergillosis: manages invasive aspergillus infections when alternative therapy is unsuitable.
• Candidiasis: resolves mucosal and systemic candidal infections resistant to other agents.

• Itraconazole inhibits the fungal cytochrome P450 enzyme lanosterol 14α‑demethylase, a key step in ergosterol synthesis. By blocking this enzyme, the drug disrupts the formation of the fungal cell membrane, leading to increased membrane permeability and inhibition of fungal growth. The selective inhibition of ergosterol production provides a broad spectrum of activity against many yeasts and molds while sparing human cells.

Itraconazole may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Nausea: mild stomach upset often occurring after the dose.
• Vomiting: occasional expulsion of stomach contents.
• Abdominal pain: cramping or discomfort in the stomach area.
• Headache: transient head pain not requiring medical intervention.
• Rash: skin redness or itching without systemic involvement.
• Elevated liver enzymes: mild, reversible increase in hepatic transaminases.

Serious or Rare Side Effects

• Hepatotoxicity: severe liver injury that may present with jaundice.
• Stevens‑Johnson syndrome: rare but life‑threatening skin reaction.
• Cardiac failure: worsening of pre‑existing heart conditions.
• Visual disturbances: blurred vision or photophobia.
• Severe hypotension: sudden drop in blood pressure.
• Anaphylaxis: acute allergic reaction requiring emergency care.

When prescribing or dispensing itraconazole, several precautionary measures should be observed to ensure patient safety.

• Liver function monitoring: assess baseline hepatic enzymes and repeat during therapy.
• Drug interaction review: evaluate concomitant medications that are CYP3A4 substrates or inducers.
• Cardiac assessment: avoid use in patients with known congestive heart failure.
• Pregnancy counseling: discuss potential risks as safety data are limited.
• Hypersensitivity check: confirm no known allergy to itraconazole or other azoles.
• Store below 25°C: keep in the original pack, protect from moisture.

Itraconazole interacts with several medicines through CYP3A4 inhibition or induction, requiring careful management.

Major Interactions (Avoid)

• Rifampin: strong CYP3A4 inducer that markedly reduces itraconazole exposure.
• Carbamazepine: enzyme inducer that can lead to therapeutic failure.
• St. John’s wort: herbal inducer that decreases itraconazole plasma levels.

Moderate Interactions (Monitor Closely)

• Warfarin: increased anticoagulant effect may require dose adjustment.
• Digoxin: higher serum concentrations possible, monitor cardiac status.
• Oral contraceptives: reduced efficacy may occur, advise alternative contraception.