Placebo-controlled Study On Efficacy Of N-acetylysteine High Dose In Exacerbation Of Chronic Obstructive Plumonary Disease

Objective:To investigate placebo-controlled study the efficacy of N-acetylcysteine1200mg(600twice a day) in acute exacerbation rate, lung function and quality of life in patientssuffering from moderate to severe Chronic Obstructive Pulmonary Disease (COPD).Method:1. The method of patients selected was used by convenience sampling.40patientssuffering from moderate to severe chronic obstructive pulmonary disease were selectedfrom the Department of the first one Hospital of Dalian Medical University betweenAugust2009to December2011, age40-80years old (including40and80years ofage).Diagnostic criteria is the diagnosis and treatment of chronic obstructive pulmonarydisease guidelines (2007) revision. Selected patients require acute exacerbation rate oftwo times in the last two years, but does not consider the hospital and patients with verysevere (FEV1<25%predicted). Selected patients are grouped according to the principleof double-blind controlled study, patients received the same opportunities for access toN-acetylcysteine or placebo-controlled group, each for50%.2. During the whole course of treatment, patients need to go to the hospital werefollowed up for seven times. In addition, the researchers on the patient’s condition ofmonthly telephone follow-up and give appropriate treatment advice.3.Throughout the course of treatment，the patients respectively take one pieces oftest drugs at breakfast and dinner after5minutes. Patients were asked to recordtheir own discomfort and other drugs recorded on the issued diary card at any time.Patients with significant disease or required hospitalization and so on, especiallypulmonary exacerbations, get in touch with the researchers in time. 4. This study does not allow for patient take of systemic antibiotics, oral orparenteral adrenal cortex hormones, expectorant, antitussive mucolytic in the stablestage. Patients must use any of these drugs, need to take the medicine recorded on diarycards, and inform researchers.5. Lung function test. During the follow-up period, patient do pulmonary functiontests by the same experienced professionals completed.6. St. George’s Respiratory Questionnaire (SGRQ) investigation. Every patientunder the unified guidance language, independently complete the questionnaires andprofessionals to explain do not understanding the part. SGRQ questionnaire with50items, is composed of the respiratory symptoms, activity limitation, disease impact. Thescore is divided into three small score and one total score. The range of score is0-100,the higher score was represented the worse the quality of life.Result:1.40patients completed36cases, lost to the4cases. Unblinding show:N-acetylcysteine group of19cases,17cases of the placebo-controlled group. Before thetwo groups of patients were enrolled into the general information were no significantdifference (P<0.05). N-acetylcysteine group, the level of FVC%, FEV1%, FEV1/FVC,after treatment were no significant difference compared with that at the beginning oftreatment (P>0.05). In the placebo-controlled group, the level of FVC%, FEV1%,FEV1/FVC, after treatment were decreased compared with that at the beginning oftreatment (P <0.01). After treatment two groups, lung function indicators in FVC%,FEV1/FCV (L), FEV1%, compared with before treatment, the effect between twogroups has significant difference (P <0.05).2. N-acetylcysteine group, SGRQ questionnaires of the respiratory symptom scores,the limitation of activity score, the disease impact score, the total score, after treatmentwere decreased compared with that at the beginning of treatment (P <0.01). In thePlacebo-controlled group, SGRQ questionnaires of the respiratory symptom scores, thelimitation of activity score, the disease impact score, total score, after treatment were nosignificant difference compared with that at the beginning of treatment. Aftertreatment two groups, SGRQ questionnaires of the respiratory symptom scores, aftertreatment were no significant difference(P>0.05), the limitation of activity score, thedisease impact score, the total score, after treatment were significant differencecompared with that at the beginning of treatment(P<0.05).3. N-acetylcysteine and placebo-controlled groups compared with the year of acute exacerbation, was statistically significant difference (P <0.05).Conclusion:1. High dose of N-acetylcysteine (NAC) has reducing acute exacerbations rate ofpatients suffering from moderate to severe COPD.2. High dose of N-acetylcysteine (NAC) has delaying lung function decline ofpatients suffering from moderate to severe COPD.3. High dose of N-acetylcysteine (NAC) has clear improving the quality of life ofpatients suffering from moderate to severe COPD.