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Extended-Spectrum Triazole — Aspergillus / Mucor / Prophylaxis in Immunocompromised

Posaconazole

Brand names: Noxafil

Posaconazole is a broad-spectrum triazole antifungal used for the treatment and prophylaxis of invasive fungal infections, including aspergillosis and infections caused by some moulds such as mucormycosis, particularly in immunocompromised patients.

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 cytochrome P450-dependent lanosterol 14-alpha-demethylase, blocking ergosterol synthesis and disrupting the integrity of the fungal cell membrane.

Prescribing in practice

  • It is a potent CYP3A4 inhibitor and is contraindicated with several drugs (including certain statins, ergot alkaloids and some agents that prolong the QT interval), so a thorough interaction check is essential before prescribing.
  • Absorption differs between formulations: the older oral suspension depends heavily on food and gastric acidity, whereas the gastro-resistant tablet and intravenous forms give more reliable exposure.
  • It can prolong the QT interval and cause hepatotoxicity, so caution is needed in patients with relevant risk factors.

Monitoring

Monitor liver function and electrolytes, and use therapeutic drug monitoring of plasma concentrations to confirm adequate exposure where indicated.

Counselling the patient

  • If you are taking the oral suspension, take it with food or a nutritional supplement to help absorption.
  • Tell the team about all your other medicines, as posaconazole interacts with many drugs.
  • Report yellowing of the skin or eyes, dark urine or palpitations.

Evidence & guidelines

Posaconazole prophylaxis reduced invasive fungal infections in high-risk neutropenic and graft-versus-host disease patients in pivotal randomised trials.

Reference: ESCMID/ECMM Aspergillosis Guidelines; ECMM/ISHAM Mucormycosis Guidelines; EORTC MSG Posaconazole Prophylaxis Trial; 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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