106 Descriptive analysis of inhaled antibiotic combination therapy in a large Belgian referral center

Abstract

Objectives The recent advent of new inhaled antibiotic treatments heralded the use of combination inhaled antibiotic therapy (CIT). We aimed to analyze the frequency of CIT use in our patients and what combinations were preferred. Methods All patient files from the University Hospital of Leuven, Belgium, were searched for periods of CIT. Inhalation therapy encompassed tobramycin inhalation solution (TIS), tobramycin inhalation powder (TIP), aztreonam lysine inhalation (AZ), natriumcolistimethaat dry powder inhalation (ColiDPI) or nebulized (ColiNeb). We also compared FEV1 at start CIT (outside an exacerbation) with values at 6 months and 1 year. Results Of a total of 99 patients on inhaled antibiotic treatment, 50 patients (mean age 28±8 y; 52% female) used CIT. Of them, 76% were DF508 homozygous, 10% was heterozygous and 14% had another mutation. All but one patient took inhaled antibiotic monotherapy before starting CIT. Seven patients tried 3 different CIT regimens, 18 had two different CIT and the remaining 25 only took one CIT. The most used CIT were AZ/ColiDPI (28 patients), AZ/ColiNeb (22 patients) and TIS/ColiNeb (16 patients). Only 7 patients tried TIS/ColiDPI, 5 had TIS/AZ and one ColiDPI/ColiNeb. First analysis showed that the only significant improvement in FEV1 from start of CIT was seen in the AZ/ColiNeb group (+4.6%; p = 0.02) at 6 months, but failed to remain significant at 1 year (+1.8%; p = 0.35). Conclusion CIT is often used in daily clinical practice without sound scientific evidence. Some combinations were more prevalent than others without an evident reason. More research is needed to elucidate the best CIT in terms of clinical improvement.