Posaconazole

Note: For haemato-oncology patients see management and prevention of invasive fungal infection (IFI) in adult haemato-oncology patients guideline

*Dose should be administered during or immediately after a meal, or a nutritional supplement in patients who cannot tolerate food, to enhance the oral absorption and to ensure adequate exposure.

 ** For oral administration tablets are the preferred formulation over the oral suspension to optimise plasma concentrations.

Oral: No dose adjustments but carry out therapeutic drug monitoring

Intravenous: Discuss with Micro/ID or pharmacy. Doses for treatment courses may need to be adjusted for patients weighing 140kg or more.

Renal impairment

• Oral: No dose adjustment required
• IV: No dose adjustment required. If creatinine clearance is less than 50 mL/min accumulation of the intravenous vehicle Betadex Sulfobutyl Ether Sodium (SBECD) can occur. 
  • Consider if oral posaconazole can be used.
  • If IV used, monitor serum creatinine and if increases occur review use of IV posaconazole and consider changing to oral posaconazole or alternative antifungal. Discuss with Micro/ID.

Hepatic impairment

No dose adjustment required. A higher plasma concentration is expected in patients with hepatic impairment. Monitor for signs of toxicity. 

Therapeutic Drug Monitoring is required. See Therapeutic Drug Monitoring (TDM) for Antifungal Agents

Before posaconazole is started see the Summary of Product Characteristics (SPC) for posaconazole for information about interactions, cautions and contraindications.

• The co-administration of posaconazole with several medications is contraindicated. See SPC for more information.
• Caution is recommended for the use of posaconazole with several medications. See SPC for more information.

Contraception: Woman of childbearing age MUST use effective contraception during treatment with posaconazole. See SPC for more information.

Pregnancy: Manufacturer recommends avoid unless potential benefit to mother outweighs potential risk to foetus. Insufficient data in pregnant people. Toxicity shown in animal studies.

Breastfeeding: Discuss with pharmacy.

• Posaconazole may cause QT prolongation and cardiac arrhythmias.
  • Posaconazole must not be administered with medicinal products that are substrates for CYP3A4 and are known to prolong the QTc interval. See SPC for more information.
  • Posaconazole should be administered with caution to patients with pro-arrhythmic conditions. 
• Monitor LFTs before treatment is started then regularly during use of posaconazole.
• Posaconazole may cause increased risk of photosensitivity reaction. Patients should be advised to avoid sun exposure during treatment and use adequate protection such as protective clothing and sunscreen with a high sun protection factor (SPF).
• The OUH Antifungal Patient Information Leaflet can be found HERE
• Posaconazole tablets and oral suspension are NOT interchangeable. Seek advice from Pharmacy if changing between formulations. See Posaconazole (Noxafil): tablets and oral suspension are not directly interchangeable for more information

• Merck Sharp & Dohme (UK) Limited. Summary of Product Characteristics. Noxafil 40mg/ml oral suspension [online]. Last revision of the text: 16/10/24. Accessed via: www.emc.medicines.org.uk Accessed 9/5/25
• Merck Sharp & Dohme (UK) Limited. Summary of Product Characteristics. Noxafil 300 mg concentrate for solution for infusion [online]. Last revision of the text: 16/10/24. Accessed via: www.emc.medicines.org.uk Accessed 9/5/25
• Merck Sharp & Dohme (UK) Limited. Summary of Product Characteristics. Noxafil 100 mg gastro-resistant tablets [online]. Last revision of the text: 16/10/24. Accessed via: www.emc.medicines.org.uk Accessed 9/5/25
• The Renal Drug Database. Posaconazole. [online]. Last updated 28/10/24. Accessed via https://renaldrugdatabase.com Accessed 9/5/25
• BNF online accessed via www.medicinescomplete.com Accessed 9/5/25
• MHRA. Drug Safety update (September 2016) Posaconazole (Noxafil): tablets and oral suspension are not directly interchangeable. Accessed at https://www.gov.uk/drug-safety-update/posaconazole-noxafil-tablets-and-oral-suspension-are-not-directly-interchangeable
• Sanford Guide. Posaconazole [Internet] Last revision of the text: 7/4/25. Accessed 9/5/25
• Sanford Guide. Obesity dosing adjustment [Internet] Last revision of the text: 25/4/25. Accessed 9/5/25
• Luke, David R et al. “Review of the basic and clinical pharmacology of sulfobutylether-beta-cyclodextrin (SBECD).” Journal of pharmaceutical sciences vol. 99,8 (2010): 3291-301. doi:10.1002/jps.22109
• Wasmann, R. E., Smit, C., van Donselaar, M. H., van Dongen, E. P. A., Wiezer, R. M. J., Verweij, P. E., Burger, D. M., Knibbe, C. A. J., & Brüggemann, R. J. M. (2020). Implications for IV posaconazole dosing in the era of obesity. The Journal of antimicrobial chemotherapy, 75(4), 1006–1013. https://doi.org/10.1093/jac/dkz546