High-dose oral N-acetylcysteine fails to improve respiratory health status in patients with chronic obstructive pulmonary disease and chronic bronchitis: a randomized, placebo-controlled trial.

BACKGROUND: Clinical outcomes are worse in patients with COPD and chronic bronchitis. N-acetylcysteine (NAC) is commonly prescribed for such patients but with uncertain clinical benefits. We postulated that oral NAC, at much larger doses than those ordinarily prescribed, would improve clinical outcomes in a subset of patients with COPD and chronic bronchitis. OBJECTIVE: The aim of this study was to determine whether very high-dose NAC would improve respiratory health status in patients with COPD and chronic bronchitis. METHODS: Patients with COPD and chronic bronchitis were enrolled in a randomized, controlled, double-blinded trial. Patients received oral NAC (1,800 mg) or matching placebo twice daily for 8 weeks in addition to their usual respiratory medications. The primary outcome, respiratory health status, was assessed by changes in the St George's Respiratory Questionnaire. The effects of NAC on lung function and circulating markers of oxidative stress and inflammation were also evaluated. RESULTS: We terminated the study prematurely because new external information suggested the possibility of a safety issue. Of the planned 130 patients, 51 were randomized and 45 (22 in the placebo arm and 23 in the NAC arm) completed the study. There was no statistically significant difference between changes in the St George's Respiratory Questionnaire total score, comparing NAC to placebo (adjusted mean difference, 0.1 U; 95% CI, -7.8 to 8.18 U; P=0.97). There were also no significant NAC-related improvements in any of the secondary outcomes. CONCLUSION: In this 8-week trial, we were unable to show any clinical benefit from a very high dose of NAC in patients with COPD and chronic bronchitis.

Infectious complications in chronic kidney disease.

Infectious complications in individuals with chronic kidney disease (CKD) pose a significant source of morbidity and mortality. The overall scope of major infectious complications has, however, received little attention even though some of these events may be preventable. We reviewed infectious hospitalization rates in the CKD and end-stage renal disease (ESRD) populations, comparing them with the non-CKD and non-ESRD groups. We also reviewed preventive vaccination rates for influenza, pneumonia, and pneumococcal pneumonia to assess areas of potential improvement. We reviewed the medical literature and present findings based on hospitalization rates for pneumonia, sepsis/bacteremia, and urinary tract infections in the Medicare CKD, ESRD, and non-CKD populations. Vaccination rates were determined from submitted claims for services with specific codes for the vaccinations. Regardless of the primary cause for the development of CKD, primary kidney disease or secondary to hypertension, diabetes mellitus, or other chronic condition, patient outcomes after the development of infections were 3 to 4 times worse than in the non-CKD population. Influenza vaccination rates were 52%, far less than the target of 90%. Pneumococcal pneumonia vaccination rate was only 13.5%, far less than recommended. CKD is associated with significant major infectious complications, which occur at rates 3 to 4 times the general population. Providers can improve prevention by using fewer dialysis catheters and increasing vaccination rates for influenza and pneumococcal pneumonia.