Pharmacological effects of lysozyme on COPD and bronchial asthma with sputum: A randomized, placebo-controlled, small cohort, cross-over study

BackgroundMucolytic agents are often used in Japan to ease excessive mucus production in patients with chronic obstructive pulmonary disease (COPD) or bronchial asthma (BA); the treatment ameliorates dyspnea and improves quality of life (QOL).AimEfficacy and safety of lysozyme hydrochloride (LYS), an oral mucolytic enzyme preparation, for patients with COPD or BA were investigated.Patients and methodsThis study was a placebo-controlled, double-blind, randomized, cross-over design. Twenty-four patients with COPD and twenty-four patients with BA were enrolled. LYS or placebo was administered for 28 days in each treatment period, with a 28-day washout between the first and second treatment periods. The results of spirometry, impulse oscillometry system (IOS) examination, fractional exhaled nitric oxide (FeNO) measurement, as well as the changes in the subjective symptoms, were evaluated after the treatment period.ResultsOn spirometry, airway function (FEV1) improved in patients with COPD after administration of LYS (LYS vs placebo: 0.08 L vs 0.029 L, p = 0.030). Similar trends were also found in %FEV1 in COPD patients. On IOS examination, resistance of the respiratory system at 5 Hz levels was significantly improved only in patients with COPD (LYS vs placebo: −0.455 cm H2O/L/s vs 0.095 cmH2O/L/s, p = 0.012). Similar trends were found in terms of the resistance of the respiratory system at 20 Hz, and of the reactance area. In the COPD assessment test, subjective symptoms also significantly improved in patients with COPD during the LYS treatment period (improvement rates—LYS vs. placebo: 69.6% vs. 39.1%; p = 0.022). A similar effect of LYS was not seen in BA patients.ConclusionLYS, a mucolytic agent, has capability to improve the function of peripheral airways in patients with COPD, which leads to improvements of the patients' symptoms and QOL.