Posaconazole: Uses, Interactions and Safety

Uses

Posaconazole is a systemic triazole antifungal used to prevent invasive fungal infection in selected people with severe immune suppression. Depending on the product and country, it also treats invasive aspergillosis, certain difficult fungal infections, or Candida infection in the mouth and throat. The indication must be checked against the exact formulation.

Administration

Oral suspension and delayed-release tablets have different absorption and administration instructions and must not be exchanged milligram for milligram. Suspension is taken with food or the nutritional support specified in its leaflet. Tablets are swallowed whole. A separate intravenous product is given by healthcare professionals. Persistent vomiting or diarrhoea can compromise treatment.

Safety

Tell the team about liver disease, abnormal heart rhythms and low potassium or magnesium. Liver tests and electrolytes may need checking. Palpitations, fainting, yellow skin, dark urine, severe rash or breathing difficulty require prompt assessment. Posaconazole can prolong the QT interval and has also been associated with high blood pressure and low potassium from pseudoaldosteronism.

Interactions

Posaconazole strongly inhibits CYP3A4. Some combinations are prohibited, including pimozide, ergotamine and certain statins. Tacrolimus and ciclosporin need specialist adjustment and blood-level monitoring. Venetoclax restrictions depend on the cancer and treatment phase. Rifabutin and phenytoin may reduce antifungal exposure. Acid-suppressing medicines and metoclopramide particularly affect the suspension; the tablet evidence differs.

Pregnancy and breastfeeding

Pregnancy requires specialist assessment because human information is limited and animal studies raise concern. Discuss contraception and breastfeeding before treatment. The Turkish product information advises interrupting breastfeeding during therapy.

Adverse effects

Nausea, vomiting, diarrhoea, abdominal discomfort and headache are reported. Abnormal liver tests also occur. The underlying illness and accompanying medicines can contribute to symptoms, so persistent or severe effects should be reported rather than managed by changing treatment independently.

Sources

• Posaconazole delayed-release tablets and oral suspension: US prescribing information
• Turkish NOXAFIL oral-suspension product information
• Turkish NOXAFIL tablet product information
• MYCOBUTIN (rifabutin) capsules: US prescribing information
• Turkish MYCOBUTIN product information
• KERENDIA: EMA Summary of Product Characteristics
• PROCORALAN: EMA Summary of Product Characteristics
• Ranolazine Umedica 750 mg prolonged-release tablets: SmPC
• Lurasidone 18.5 mg film-coated tablets: SmPC
• ELIQUIS: EMA Summary of Product Characteristics
• Rivaroxaban Sandoz 10 mg film-coated tablets: SmPC
• INSPRA (eplerenone): US prescribing information
• MULTAQ (dronedarone): US prescribing information
• BRILIQUE (ticagrelor): EMA product information
• Quetiapine tablets: US prescribing information
• Colchicine 500 micrograms Tablets: Summary of Product Characteristics