Posaconazole

What it is and how it works

Mechanism of Action Posaconazole is an azole antifungal agent . Mechanism of Action Posaconazole blocks the synthesis of ergosterol, a key component of the fungal cell membrane, through the inhibition of cytochrome P-450 dependent enzyme lanosterol 14α-demethylase responsible for the conversion of lanosterol to ergosterol in the fungal cell membrane. This results in an accumulation of methylated sterol precursors and a depletion of ergosterol within the cell membrane thus weakening the structure and function of the fungal cell membrane. This may be responsible for the antifungal activity of posaconazole.

Indications

Posaconazole is an azole antifungal indicated as follows: • Posaconazole is indicated for the treatment of invasive aspergillosis as follows: o Posaconazole injection : adults and pediatric patients 2 years of age and older who weigh 10 kg or greater. • Posaconazole is indicated for the prophylaxis of invasive Aspergillus and Candida infections in patients who are at high risk of developing these infections due to being severely immunocompromised, such as hematopoietic stem cell transplant (HSCT) recipients with graft-versus-host disease (GVHD) or those with hematologic malignancies with prolonged neutropenia from chemotherapy as follows: o Posaconazole injection : adults and pediatric patients 2 years of age and older who weigh 10 kg or greater.

Dosage and administration (summary)

• Posaconazole injection must be administered through an in-line filter. • Administer posaconazole injection by intravenous infusion over approximately 90 minutes via a central venous line. ( 2.1 , 2.6 ) • Do NOT administer posaconazole injection as an intravenous bolus injection. • See the full prescribing information for important administration instructions and preparation instructions for posaconazole injection ( 2.5 , 2.6 ) • For adult and pediatric patients aged 2 years of age and older, see the Full Prescribing Information for dosing recommendations for posaconazole injection based on the indication, age, and weight associated with the dosage form ( 1.1 , 1.2 , 2.1 , 2.2 , 2.3 ) Impor…

Contraindications

• Known hypersensitivity to posaconazole or other azole antifungal agents. • Coadministration of posaconazole with the following drugs is contraindicated; posaconazole increases concentrations and toxicities of: • Sirolimus: ( 4.2 , 7.2 ) • CYP3A4 substrates (pimozide, quinidine): can result in QTc interval prolongation and cases of torsades de pointes (TdP) ( 4.3 , 5.2 , 7.2 ) • HMG-CoA Reductase Inhibitors Primarily Metabolized through CYP3A4 ( 4.4 , 7.2 ) • Ergot alkaloids ( 4.5 , 7.2 ) • Ven…

Warnings and precautions

• Calcineurin-Inhibitor Toxicity : Posaconazole increases concentrations of cyclosporine or tacrolimus; reduce dose of cyclosporine and tacrolimus and monitor concentrations frequently. • Arrhythmias and QTc Prolongation : Posaconazole has been shown to prolong the QTc interval and cause cases of TdP. Administer with caution to patients with potentially proarrhythmic conditions. Do not administer with drugs known to prolong QTc interval and metabolized through CYP3A4.

Pregnancy

Pregnancy Risk Summary Based on findings from animal data, posaconazole may cause fetal harm when administered to pregnant women. Available data for use of posaconazole in pregnant women are insufficient to establish a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes.

Storage and supply

How Supplied Posaconazole Injection Posaconazole injection is a clear, colorless to yellow sterile liquid in single-dose Type I glass vials closed with bromobutyl rubber stopper and aluminum seal containing 300 mg of posaconazole in 16.7 mL of solution (18 mg of posaconazole per mL) (NDC 67457-665-20).

Source: Posaconazole (Posaconazole) — US FDA prescribing information, 2026-07-15, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.