MSRA-2752

A 56-year-old man is being seen in the respiratory clinic after being discharged from the hospital two weeks ago following a COPD exacerbation. Despite having optimised medications, he has had three hospitalisations this year and five last year. He does not smoke or drink alcohol. The consultant has reviewed his recent investigations and imaging and is considering recommending additional medication to reduce exacerbations. What medication is most likely to be suggested for this patient?