Smith C A, Adamson D L, Choudry N B, Fuller R W
St Mary's Hospital Medical School, London, UK.
Eur Respir J. 1991 Oct;4(9):1078-9.
Cough is frequently the presenting symptom of bronchial asthma, although cough can result from a wide variety of other respiratory disease. Treatment of chronic cough has proved extremely difficult. It has been suggested that treatment with bronchodilators may reduce the symptom of cough. In this study the effect of altering airway tone on the sensitivity of the cough reflex was determined. Twelve normal, healthy volunteers took part. The number of coughs following inhalations of single breaths of doubling concentrations of capsaicin (1.95-500 microM) was recorded before and after doses of salbutamol, methacholine and saline which altered forced expiratory volume in one second (FEV1) by 6.2 +/- 2.6%, -8.8 +/- 3.2% and -0.18 +/- 1.38%, respectively. In a further study the cough response was recorded before and after doses of salbutamol and ipratropium bromide, both of which reduced baseline respiratory resistance and resistance measured after capsaicin. Ipratropium bromide, salbutamol and methacholine, despite having significant effects on airway tone, did not change the sensitivity of capsaicin-induced cough. Thus, if bronchodilator drugs are antitussive in non-asthmatic patients, then this is unlikely to be due to an effect on the sensitivity of the cough reflex.
咳嗽常常是支气管哮喘的首发症状，尽管咳嗽也可能由多种其他呼吸道疾病引起。事实证明，慢性咳嗽的治疗极其困难。有人提出使用支气管扩张剂进行治疗可能会减轻咳嗽症状。在本研究中，测定了改变气道张力对咳嗽反射敏感性的影响。12名正常、健康的志愿者参与了研究。在给予沙丁胺醇、乙酰甲胆碱和生理盐水后，记录吸入浓度加倍的辣椒素（1.95 - 500微摩尔）单次呼吸后的咳嗽次数，这些药物分别使一秒用力呼气量（FEV1）改变了6.2±2.6%、-8.8±3.2%和-0.18±1.38%。在进一步的研究中，记录了给予沙丁胺醇和异丙托溴铵前后的咳嗽反应，这两种药物均降低了基线呼吸阻力以及辣椒素刺激后的呼吸阻力。尽管异丙托溴铵、沙丁胺醇和乙酰甲胆碱对气道张力有显著影响，但它们并未改变辣椒素诱发咳嗽的敏感性。因此，如果支气管扩张剂药物对非哮喘患者有镇咳作用，那么这不太可能是由于对咳嗽反射敏感性的影响所致。
