The following is a summary of “Therapeutic drug monitoring in cystic fibrosis and associations with pulmonary exacerbations and lung function,” published in the April 2023 issue of Pulmonology by Katz, et al.
Despite longer life expectancies due to cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy, pulmonary exacerbations continue to cause morbidity in cystic fibrosis (CF) patients. Intravenous antibiotics treat exacerbations, but achieving adequate concentrations was challenging. In addition, the effects of therapeutic drug monitoring (TDM) of beta-lactams on exacerbations and lung function have not been studied.
The study included 32 CF patients admitted for exacerbations, colonized with Pseudomonas aeruginosa, and receiving CFTR therapy for at least one year. Demographics, antibiotic regimens, forced expiratory volume 1 s (FEV1), and exacerbation history were obtained. Plasma concentrations, FEV1, and exacerbation history were also obtained before and after TDM, including peak and trough plasma concentrations of piperacillin-tazobactam and cefepime using liquid chromatography with mass spectrometry. T-tests and Mann-Whitney U tests were used to compare FEV1 and exacerbations pre- and post-TDM and free trough-to-minimum inhibitory concentration ratio (fCmin/MIC) ≥1 and ≥4.
TDM was associated with a decrease in exacerbations/year from 1.91 to 1.31 (P = 0.04), and in patients with ≥2 exacerbations per year, there was a longer exacerbation-free interval after TDM (196.2 vs. 103.7 days, P = 0.02). In addition, the decline in FEV1% predicted after TDM to the first exacerbation was −4.9 compared to −9.7 prior (P = 0.03).
TDM reduces pulmonary exacerbations, prolongs the time between pulmonary exacerbations, and lowers the expected reduction in FEV1% for cystic fibrosis pulmonary exacerbations.
Source: resmedjournal.com/article/S0954-6111(23)00125-7/fulltext
