Background Meropenem is commonly used intravenously in CF patients infected with Pseudomonas aeruginosa, but there is limited evidence of its tolerability and effectiveness when used as a nebulised treatment.

Aim To evaluate the use of nebulised meropenem in our large UK adult CF centre.

Methods Medical records of patients who had trialled nebulised meropenem between 2008–2012 were reviewed for: demographics, lung function, BMI, sputum microbiology, indications and tolerability and number of exacerbations requiring IV antibiotics.

Results 37 patients (18 male) trialled nebulised meropenem, with median age (IQR) 27 (20–37) years and FEV1% predicted 48% (35–64%). Patients received a 250 mg dose reconstituted with water for injection preceded by a bronchodilator. All patients were chronically infected with P. aeruginosa. The most common treatment indications were deteriorating condition or intolerance to other antibiotic nebulisers (21/37), with additional indications including treatment of Burkholderia cepacia complex (8/37) and non-tuberculous mycobacteria (8/37). 22/37 continue to tolerate the drug well. 10 of these 22 had previously been intolerant to Tobramycin Inhalation Solution (TIS) and 1 intolerant to nebulised amikacin. 4/37 discontinued due to no benefit or poor concordance. 11/37 did not tolerate nebulised meropenem, reporting adverse effects including chest tightness, increased cough, chest discomfort, nausea and lethargy. 6 of these 11 had previously been intolerant to TIS and 2 were intolerant to amikacin. There were no significant changes in lung function, BMI or requirement for IV antibiotics comparing the 12-month periods before and after commencing nebulised meropenem.

Conclusion Nebulised meropenem is generally well tolerated in CF adults and offers an alternative antibiotic choice for people with CF unable to tolerate other treatments.