Plasma levels of posaconazole vary substantially between patients, resulting in barriers to appropriate dosing. A study by researchers from Italy was designed to investigate posaconazole pharmacokinetics and evaluate therapeutic drug monitoring practices in adult patients.
Plasma samples were collected from 172 adult patients that were being treated with posaconazole for invasive fungal infections. The researchers linked these samples to patient data, including age, gender, BMI, ethnicity and posaconazole dose.
The researchers found that sex was significantly associated with plasma posaconazole concentrations (males>females; p=0.028), which could influence dosing protocols if the result is repeated in further studies.
However, the study did not control for a number of other factors that could influence plasma concentration, including total bodyweight and type of infection. Studying a broader range of factors using multivariate statistical methods would improve our current understanding of the pharmacokinetics of posaconazole.