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Triazole antifungal

Itraconazole

Brand names: Sporanox

Itraconazole is an oral triazole antifungal used to treat dermatophyte infections, onychomycosis, candidiasis, pityriasis versicolor and systemic fungal infections such as aspergillosis and histoplasmosis.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It inhibits fungal lanosterol 14-alpha-demethylase, a cytochrome P450 enzyme, reducing ergosterol synthesis and compromising the fungal cell membrane.

Prescribing in practice

  • Contraindicated in patients with evidence of ventricular dysfunction or a history of heart failure, as it has a negative inotropic effect and can precipitate cardiac failure.
  • As a strong CYP3A4 inhibitor it has numerous serious interactions, so all concomitant drugs should be checked against the SPC.
  • Capsule absorption depends on gastric acidity and is enhanced by food, so antacids and acid-suppressing drugs can substantially reduce exposure.

Monitoring

Check liver function before and during prolonged treatment and review for symptoms of cardiac failure throughout therapy.

Counselling the patient

  • Swallow capsules with a meal to aid absorption.
  • Seek advice promptly if you develop swelling of the legs, breathlessness or signs of liver problems.
  • Do not start any new medicine, including herbal products, without checking for interactions.

Evidence & guidelines

Prescribing reflects the SPC and MHRA warnings regarding heart failure risk and the drug's interaction profile.

Reference: MHRA Drug Safety Update; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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