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Introduction and ObjectivesChronic cough is a poorly understood condition with a limited number of treatment options available. Gabapentin and pregabalin are used in the treatment of neuropathic pain and may have some efficacy in patients with refractory chronic cough.1,2We evaluated the real-world outcomes of using these medicines in a tertiary cough clinic.MethodsWe performed a retrospective review of new referrals to a tertiary cough clinic (October 2013-October 2015). Patient characteristics (age, sex, duration of cough and test results) were collected. Follow up clinic letters were reviewed until April 2017. We recorded details regarding the prescribing of gabapentin and pregabalin for patients with refractory chronic cough, their impact on cough and the associated side effects.Results136 new patients were reviewed (mean age 56.3 years, 98 (72.1%) female) with a mean duration of cough of 7.5 years (SD 12.2). Gabapentin or pregabalin was prescribed for 38 patients (9 gabapentin and 29 pregabalin). Highest dose achieved was 1800 mg/day for gabapentin and 300 mg/day for pregabalin. Overall, fifteen patients (39%) responded favourably to these medicines initially. Fourteen (37%) tolerated them but derived no benefit and stopped the medication. Nine patients (24%) developed immediate side effects and were unable to tolerate the medications. Out of the 15 patients that tolerated these medicines, only 8 (21%) were able to continue with therapy long term, as the other seven (18%) eventually developed intolerable side effects. The most common side effect was drowsiness (see below).[Figure]ConclusionsOur data suggests that in clinical practice, alpha-two delta ligands are effective in a subgroup of chronic cough patients, but side effects may outweigh their potential benefits, affecting nearly half the population trialled. Prospective work is needed to objectively quantify their anti-tussive effects and tolerability over longer treatment periods, allowing clinicians and patients to better understand the risk-benefit ratio associated with their use.ReferencesRyan, NM, et al. Gabapentin for refractory chronic cough: A randomised, double-blind, placebo-controlled trial. Lancet2012;380(9853):1583–9.Vertigan, AE, et al. Pregabalin and speech pathology combination therapy for refractory chronic cough: A randomised controlled trial. Chest2016;149(3):639–48.

IntroductionStudies have shown large amounts of gastro-oesophageal reflux (GOR) in CF patients, which frequently has characteristics which may favour aspiration - asymptomatic, proximal oesophageal extent and supine. Exposure to refluxate may worsen CF lung disease, as it contains acid, digestive enzymes and microbes, which can include respiratory pathogens. We aim to establish if there is a relationship between GOR and CF lung disease.MethodWe are conducting a prospective observational study in stable CF patients, measuring oesophageal reflux with combined pH and impedance (pH-MII) and reflux symptoms using the RESQ-7 questionnaire. In a preliminary analysis we have collected retrospective data from the medical records for lung function and number of courses of intravenous antibiotics.Results21 of 30 recruited completed the study (mean age 28 years, mean FEV1 50% predicted, 19 males). Total number of reflux episodes was increased in 72% (median 89, IQR 68–132, normal range <75 episodes). High risk reflux (increased proximal and/or supine reflux) was noted in 62%. Non-acid events (median 54, IQR 21–78) were more frequent than acid events (median 36.5, IQR 13–66), but 14/21 were on acid suppression medications. 5/21 had increased total reflux parameters (median 89, IQR 68–98), but on RESQ-7 had no symptoms.Interestingly, number of intravenous antibiotic treatments positively correlated with total reflux events (r=0.45, p=0.004) and suggested potential trends with high risk parameters (e.g. proximal reflux r=0.37, p=0.1). However there were no correlation between reflux parameters and spirometry.ConclusionCF patients have large amounts of ‘high-risk’ reflux, and our data suggests a potential relationship between reflux severity and the number of pulmonary exacerbations, represented by the requirement for intravenous antibiotics. To explore this further a reliable biomarker of aspiration, such as sputum pepsin, is required.Disclosure of InterestNone Declared