Objective  To evaluate the clinical effectiveness and safety of large-dose acetylcysteine combined with tetrandrine in treatment of pneumoconiosis.

  Methods  Patients with pneumoconiosis were randomly divided into the control group (n=57) and the experimental group (n=57). The control group was given the conventional therapy, anti-infection treatment if needed. The experimental group was treated with acetylcysteine combined with tetrandrine for 24 weeks, on the basis of conventional therapy.

  Results  After treatment, the ratios of patients with cough, sputum expectoration, shortness of breath and chest pain in the experimental group were significantly lower than those in the control group(P < 0.05). After 12 weeks and 24 weeks of treatment, the forced expiratory volume in the first second (FEV₁), the forced vital capacity(FVC) and FEV₁/FVC ratios of the patients in control group were decreased compared with those at pre-treatment stage(P < 0.05), while the FEV₁, FEV₁/FVC and FVC of the patients in experimental group showed no significant change(P > 0.05). The curative effect of the experimental group was better than that in the control group(P < 0.05). After 24 weeks of treatment, the carbon monoxide diffusion function(DLco) in the experimental group was higher than that in the control group(P < 0.05). The ratio of new respiratory infections in the experimental group was significantly lower than that in the control group(P < 0.05). One patient in the experimental group had skin pigmentation, and the adverse reaction ratio was 1.75%.

  Conclusions  large-dose acetylcysteine combined with tetrandrine could effectively improve the clinical symptoms of patients with pneumoconiosis, maintain lung ventilation and diffusion, reduce respiratory infections, and have fewer adverse reactions. This safe and effective treatment measures are worthy of clinical application.