Noxafil (Posaconazole)

Posaconazole is an antifungal agent used to manage serious fungal infections that affect high‑risk patient groups.

• Invasive aspergillosis: helps prevent and treat this life‑threatening lung infection in neutropenic patients.
• Invasive candidiasis: used for treatment of candidemia and deep‑seated candidal infections when other agents are unsuitable.
• Prophylaxis of fungal infection: reduces incidence of invasive fungal disease in patients receiving intensive chemotherapy or hematopoietic stem‑cell transplantation.

• Posaconazole inhibits the fungal enzyme lanosterol 14α‑demethylase, a cytochrome P450‑dependent protein essential for ergosterol synthesis. Blocking this step disrupts the fungal cell membrane, leading to increased permeability and inhibition of fungal growth and replication.

Adverse reactions to intravenous posaconazole vary in frequency and severity.

Common Side Effects

• Headache
• Nausea
• Diarrhea
• Elevated liver enzymes (ALT/AST)
• Fever
• Infusion‑related reactions (e.g., flushing, chills)

Serious or Rare Side Effects

• Hepatotoxicity (severe liver injury)
• Severe hypersensitivity reactions including anaphylaxis
• QT‑interval prolongation
• Acute renal failure
• Thromboembolic events
• Visual disturbances

Posaconazole should be used with careful clinical monitoring and adherence to safety guidelines.

• Liver function monitoring: assess baseline enzymes and repeat periodically.
• Cardiac monitoring: obtain ECG in patients with known QT‑prolonging risk factors.
• Drug‑interaction review: evaluate concomitant medications that affect CYP3A4.
• Renal function: monitor serum creatinine in patients with pre‑existing kidney disease.
• Pregnancy and lactation: avoid use unless benefits outweigh risks and it is prescribed by a specialist.
• Store at ambient temperature: keep in original container, protect from light and moisture.

Posaconazole interacts with several medicines through CYP3A4 inhibition and other pathways.

Major Interactions (Avoid)

• Midazolam: may cause profound sedation or respiratory depression.
• Rifampicin: reduces posaconazole exposure, compromising efficacy.
• Certain statins (e.g., lovastatin, simvastatin): increased risk of myopathy.

Moderate Interactions (Monitor Closely)

• Tacrolimus and cyclosporine: may require dose adjustment due to increased levels.
• Warfarin: potential alteration of INR values.
• Proton pump inhibitors: may lower posaconazole absorption.
• Anticonvulsants (e.g., carbamazepine): may decrease posaconazole concentrations.