Nirmatrelvir

Lee W-H, et al. Heliyon, 2024, 10(15), e34820.

Nirmatrelvir, a key component of the COVID-19 therapeutic regimen Paxlovid, demonstrates the ability to cross the blood-brain barrier (BBB) and reach effective concentrations in the central nervous system (CNS). This study aimed to evaluate nirmatrelvir's pharmacokinetics in both blood and brain, as well as the potential interaction with herbal formulations of Scutellaria baicalensis, a traditional herbal remedy.
Using an animal model, the researchers employed microdialysis coupled with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to precisely monitor nirmatrelvir concentrations in rat plasma and brain tissue. The results indicated that, following a 15 mg/kg intravenous dose of nirmatrelvir, the area under the curve (AUC) in blood and brain were 798.3 ± 58.56 and 187.2 ± 23.46 min μg/mL, respectively. These concentrations were sustained for over 6 hours, surpassing the effective concentration (EC90) needed for antiviral activity.
Notably, pre-administration of Scutellaria baicalensis formulations for five consecutive days significantly increased nirmatrelvir's AUC in the blood, suggesting a synergistic enhancement in pharmacokinetics. This interaction could potentially maintain therapeutic levels of nirmatrelvir, improving its efficacy against COVID-19.