P106 The use of gabapentin and pregabalin for the management of chronic cough in a tertiary cough clinic

Introduction and Objectives Chronic 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. 1,2 We evaluated the real-world outcomes of using these medicines in a tertiary cough clinic. Methods We 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. Results 136 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). Conclusions Our 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. References Ryan, 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.