ABSTRACT
Refractory chronic cough due to gastroesophageal reflux is a troublesome condition unresponsive to the standard medical anti-reflux therapy. Its underlying mechanisms may include incomplete acid suppression, non-acid reflux, transient lower esophageal sphincter relaxations and esophageal hypersensitivity. The diagnosis of this disorder depends on both the findings of multi-channel intraluminal impedance-pH monitoring and the subsequent intensified anti-reflux therapy. The strategies of pharmacological treatment for refractory chronic cough due to reflux include the optimization of proton pump inhibitors and add-on therapies with histamine H2 receptor antagonists, baclofen and gabapentin. However, the further study is needed to satisfy its management.
ABSTRACT
To investigate the characteristics of gastroesophageal reflux induced cough (GERC) with airway hyperresponsiveness (AHR). Compared to patients with GERC alone and healthy subjects, cough sensitivity, multi-channel intraluminal impedance combined with pH monitoring and airway inflammation were evaluated in patients with GERC and AHR. 23 patients were definitely diagnosed as acid reflux induced GERC, 9 patients developed AHR concomitantly. When compared with GERC patients, patients with AHR had significantly increased number of proximal extent episodes (21.5 (28.6) vs. 7.5 (1.8), Z = -2.038, P = 0.042) and increased proportion of proximal extent episodes to total refluxes episodes (24.5 (13.5)% vs. 4.2 (7.3)%, Z = -2.138, P = 0.032), and the level of IL-8 in the airway of these patients was significantly higher than that in healthy subjects (71.1 (64.0) vs. 24.3 (35.2) pg/ml, Z = -2.013, P = 0.044). Gastroesophageal reflux may cause neutrophilic airway inflammation due to the acid reflux into the airway, which results in AHR. However, AHR is not definitely able to cause chronic cough. Thus differential diagnosis is required in clinical practice.
ABSTRACT
AIM: To evaluate the efficacy and safety of baclofen for treatment of refractory gastroesophageal reflux-induced chronic cough (GERC) unresponsive to standard anti-reflux therapy. METHODS: Sixteen patients with refractory GERC were given an 8-wk course of baclofen 20 mg three times a day as an add-on therapy to omeprazole. Changes in the cough symptom score, cough threshold to capsaicin, reflux symptom score and possible adverse effects were determined after treatment. The variables of multi-channel intraluminal impedance combined with pH monitoring were compared between responders and non-responders to baclofen. RESULTS: Twelve of 16 patients completed treatment. Cough disappeared or improved in 56.3% (9/16) of patients, including 6 patients with acid reflux-induced cough (66.7%) and 3 patients with non-acid reflux-induced cough (33.3%). With baclofen treatment, the cough symptom score began to decrease at week 2, was clearly decreased at week 6 and reached a minimum at week 8. At the end of therapy, the lowest concentration of capsaicin required for induction of ≥ 2 and ≥ 5 coughs increased from 0.98 (1.46) to 1.95 (6.82) µmol/L (Z = -2.281, P = 0.024) and from 1.95 (7.31) to 7.8 (13.65) µmol/L (Z = -2.433, P = 0.014), respectively, and the reflux symptom score decreased from 8.0 ± 1.6 to 6.8 ± 0.8 (t = 2.454, P = 0.023). The number of acid reflux episodes was significantly lower in responders than in non-responders. The main adverse effects were somnolence, dizziness and fatigue. CONCLUSION: Baclofen is a useful, but suboptimal treatment option for refractory GERC.
