Predictive Factors and Treatment Effects of Neuromodulators in Chronic Refractory Cough

ImportanceChronic refractory cough (CRC) has a negative impact on the quality of life of sufferers and is difficult to treat. Although previous studies have documented various treatment methods for CRC, no treatment method has proven fully effective.ObjectiveThis study investigated the treatment efficacy and adverse effects of neuromodulators (NM), Amitriptyline and Gabapentin, in the treatment of CRC, and the factors that predicted outcomes.DesignProspective data review.SettingPrivate otolaryngology clinic.ParticipantsThis study included 103 successive patients (72 female, 31 male) during the period between 2013 and 2023. Mean age of patients was 56.6 years (standard deviation: 13.5; range: 21 to 83).InterventionAll patients received treatment using NM, including Amitriptyline and Gabapentin.Main Outcome MeasuresCough Severity Index (CSI) and the Newcastle Laryngeal Hypersensitivity Questionnaire (NLHQ). The minimal important difference (MID) in CSI was calculated and used as the threshold to determine response to NM treatment.ResultsA MID of 7 or more in CSI was regarded as a response to NM χ₍₁₎² = 4.813; <i>P</i> = .028. Using this criterion, 55.6% responded to NM therapy. Chemical triggers significantly predicted responses to NM [χ₍₁₎² = 4.813; <i>P</i> = .028] while thermal, mechanical, and abnormal throat sensation triggers were not significant predictors of response. Pretreatment CSI was a significant predictor of response to NM [χ₍₁₎² = 5.603; <i>P</i> = .018]. Pretreatment NLHQ, citric acid cough threshold result, and response to superior laryngeal nerve blocks did not predict response to NM. Seventy percent of patients undergoing NM therapy experienced at least one adverse effect.Conclusion and RelevanceThe findings appeared to imply the therapeutic effects of neuromodulators on CRC, especially in patients presenting with chemical triggers. However, the adverse effect was a factor that may impact on application of this treatment method.<b>Level of Evidence: 3</b>.