Tobramycin and Beta-Lactam Antibiotic Use in Cystic Fibrosis Exacerbations: A Pharmacist Approach

Survey suggests that recommended doses and dosage regimens for antipseudomonal antibiotics for the treatment of acute pulmonary exacerbations in cystic fibrosis (CF) patients are not used, and one way to address these disparities is the involvement of pharmacists who are dedicated to CF. This is the first survey specifically designed for pharmacists at Cystic Fibrosis Foundation (CFF)-accredited centers to identify how tobramycin and antipseudomonal beta-lactams are being used. The purpose of this survey is to quantify this information and to promote future study to allow for implementation of tobramycin and beta-lactam dosage and monitoring standardization.

An anonymous national cross-sectional survey of pharmacists that are affliated with CFF-accredited programs was performed using Qualtrics.com.

The survey had a 48.5% response rate. Most pediatric pharmacists (78.6%) report using extended-interval tobramycin dosage. The most common reported starting dosage was 10 mg/kg every 24 hours; most centers aim for a maximum serum concentration (Cmax) between 20 and 40 mg/L (78.6%). A total of 26 adult pharmacists reported using extended-interval dosage (96%), using an initial dosage of 10 mg/kg/day. The most common parameters used to adjust dosage were Cmax and area under the curve (AUC; 31%); the Cmax goal was 20 to 40 mg/L (84.2%). Most respondents (79%) report using beta-lactams in combination with tobramycin. Extended-infusion and continuous-infusion beta-lactams were used more in adults than pediatric patients.

Most CF pharmacists report using extended-interval tobramycin. With the information from this survey, the establishment of future consensus recommendations by pharmacists for optimal and consistent tobramycin and antipseudomonal beta-lactam dosage and monitoring strategies needs to be considered.