September 2014 Phoenix Pulmonary Journal Club: Inhaled Antibiotics

The September 2014 pulmonary journal club focused on the utilization of inhaled antibiotics in non-cystic fibrosis (CF) bronchiectasis.

A total of four papers were reviewed, inhaled tobramycin (1), inhaled gentamicin (2),  inhaled colistin (3) and Inhaled aztreonam (4).  Each of the trials were randomized, placebo-controlled trials with small sample sizes. An aggregate sample size from all four trials totaled 255 patients in the treatment arms. The largest sample size was seen in the aztreonam trial with 134 patients in the treatment group vs. 132 in the placebo group while the smallest was in the inhaled tobramycin, with 16 patients in the treatment arm vs. 15 in placebo. The inhaled tobramycin and gentamicin studies looked at reduction in bacterial colony forming units and sputum density, whereas the inhaled colistin and aztreonam studies incorporated time to exacerbations and quality of life indicators. None of the studies incorporated an airway clearance modality. 

The results of the studies were not impressive. In the tobramycin and gentamicin trials the primary endpoints of a reduction of bacterial load and sputum density were reached but the effects were only sustained while on therapy.  The colistin trial was the most promising as it showed that a > 80% adherence to inhaled therapy resulted in reduction in Pseudomonas bacterial load, improved quality of life and a delay in time to the first exacerbation. The aztreonam study was the largest of the four trials and looked at quality of life as its primary endpoint but failed to achieve its goal. 

In the four trials the medications were well tolerated with main side effects being airway irritation and bronchospasm. There were no systemic side effects and the use of inhaled therapy did not change the bacterial resistance pattern.

The role of inhaled antibiotics in non-CF bronchiectasis remains unknown as the data is lacking. Translating what we know about CF bronchiectasis and applying it to non-CF bronchiectasis has not been successful.  Future trials need to incorporate an airway treatment protocol such as flutter valve or chest vest therapy, and continue to use varying doses durations of therapy. The mechanism of action on the meds vary from bactericidal  (colistin, aztreonam) to bacteriostatic (gentamicin, tobramycin), perhaps looking at a combination inhaled therapy for synergy is warranted? For now all we know from inhaled antibiotic therapy in non-CF bronchiectasis is that it’s fairly well tolerated with no significant systemic toxicity but its efficacy is unproven.

M Mathew, MD FCCP MCCM

Associate Editor

References

1. Couch LA. Treatment With tobramycin solution for inhalation in bronchiectasis patients with Pseudomonas aeruginosa. Chest. 2001;120(3 Suppl):114S-117S. [CrossRef] [PubMed]
2. Murray MP, Govan JR, Doherty CJ, Simpson AJ, Wilkinson TS, Chalmers JD, Greening AP, Haslett C, Hill AT. A randomized controlled trial of nebulized gentamicin in non-cystic fibrosis bronchiectasis. Am J Respir Crit Care Med. 2011;183(4):491-9. [CrossRef] [PubMed]
3. Haworth CS, Foweraker JE, Wilkinson P, Kenyon RF, Bilton D. Inhaled colistin in patients with bronchiectasis and chronic Pseudomonas aeruginosa infection. Am J Respir Crit Care Med. 2014;189(8):975-82. [CrossRef] [PubMed]
4. Barker AF, O'Donnell AE, Flume P, et al. Aztreonam for inhalation solution in patients with non-cystic fibrosis bronchiectasis (AIR-BX1 and AIR-BX2): two randomised double-blind, placebo-controlled phase 3 trials. Lancet Respir Med. 2014;2(9):738-49. [CrossRef] [PubMed]

Reference as: Mathew M. September 2014 Phoenix pulmonary journal club. inhaled antibiotics. Southwest J Pulm Crit Care. 2014;9(3):187-8. doi: http://dx.doi.org/10.13175/swjpcc125-14 PDF

August 2014 Phoenix Pulmonary Journal Club: The Use of Macrolide Antibiotics in Chronic Respiratory Disease

This month's journal club reviewed  the role of macrolide antibiotics in chronic respiratory disease. Macrolide usage was suggested from observational studies in Japan in diffuse panbroncholitis, a disorder associated with chronic respiratory infection, usually Pseudomonas aeruginosa (1). Clinical improvement was noted despite doses of antibiotics well below the minimal inhibitory concentration (MIC) of the antibiotic. This  suggested the antibiotic was likely working by an anti-inflammatory effect. These observations were extended to cystic fibrosis (CF) where prophylactic macrolide therapy in CF patients infected with Pseudomonas has become standard therapy (2). More recently, low dose macrolide therapy has been applied to non-CF lung diseases such as chronic obstructive pulmonary disease (COPD), bronchiectasis and asthma.

Time did not permit a review of all studies so a representative sample was discussed. In patients with COPD, the four randomized, placebo-controlled trials reviewed all suggested that chronic therapy with macrolide antibiotics reduced COPD exacerbations (3-5). This beneficial effect was confirmed by 2 recent meta-analysis (6,7). Similarly,  three recent randomized trials in bronchiectasis demonstrated a reduction in exacerbations (8-10). In asthma the data is not as clear. A recent trial did not demonstrate an overall reduction in asthma exacerbations or lower respiratory tract infections (11). However, in the patients with non-eosinophilic, predominantly neutrophilic, asthma there was a reduction.  An excellent review of the use of macrolides in acute and chronic asthma was recently published. (12). The article includes a review of the anti-inflammatory and immunomodulatory properties of the macrolides.

The respiratory disorders where macrolides have been shown to have clinic benefit such as diffuse panbroncholitis, cystic fibrosis, COPD, bronchiectasis and non-eosinophilic asthma are all diseases associated an influx of neutrophils into the airways. The beneficial clinic effects of macrolides are consistent with their effect in reducing neutrophil chemotactic factors such as interleukin (IL)-8 (13). However, macrolides have also been reported to have adverse clinical effects such as QT prolongation in patients with heart disease, impaired hearing and development of bacterial resistance (4,6,14). Whether all COPD patients should be treated with macrolides is controversial but most in the audience used these in patients with frequent exacerbations. It was also pointed out that other antibiotics such as the tetracyclines also have anti-inflammatory effects and have been shown to be efficacious in some respiratory diseases (15). Whether the tetracyclines are equally or more effective than the macrolides with fewer serious side effects is unknown.

Richard A. Robbins, MD¹

Allen R. Thomas, MD²

Manoj Mathew, MD³

¹Phoenix Pulmonary and Critical Care Research Foundation, ²Phoenix VA Medical Center, ³Banner Good Samaritan Medical Center.

References

1. Nagai H, Shishido H, Yoneda R, Yamaguchi E, Tamura A, Kurashima A. Long-term low-dose administration of erythromycin to patients with diffuse panbronchiolitis. Respiration. 1991;58(3-4):145-9. [CrossRef] [PubMed] 
2. Saiman L, Marshall BC, Mayer-Hamblett N, Burns JL, Quittner AL, Cibene DA, Coquillette S, Fieberg AY, Accurso FJ, Campbell PW 3rd; Macrolide Study Group. Azithromycin in patients with cystic fibrosis chronically infected with Pseudomonas aeruginosa: a randomized controlled trial. JAMA. 2003;290(13):1749-56. [CrossRef] [PubMed]
3. Seemungal TA, Wilkinson TM, Hurst JR, Perera WR, Sapsford RJ, Wedzicha JA. Long-term erythromycin therapy is associated with decreased chronic obstructive pulmonary disease exacerbations. Am J Respir Crit Care Med. 2008;178(11):1139-47. [CrossRef] [PubMed]
4. Albert RK, Connett J, Bailey WC, Casaburi R, Cooper JA Jr, Criner GJ, Curtis JL, Dransfield MT, Han MK, Lazarus SC, Make B, Marchetti N, Martinez FJ, Madinger NE, McEvoy C, Niewoehner DE, Porsasz J, Price CS, Reilly J, Scanlon PD, Sciurba FC, Scharf SM, Washko GR, Woodruff PG, Anthonisen NR; COPD Clinical Research Network. Azithromycin for prevention of exacerbations of COPD. N Engl J Med. 2011;365(8):689-98. [CrossRef] [PubMed]
5. Uzun S, Djamin RS, Kluytmans JA, Mulder PG, van't Veer NE, Ermens AA, Pelle AJ, Hoogsteden HC, Aerts JG, van der Eerden MM. Azithromycin maintenance treatment in patients with frequent exacerbations of chronic obstructive pulmonary disease (COLUMBUS): a randomised, double-blind, placebo-controlled trial. Lancet Respir Med. 2014;2(5):361-8. [CrossRef] [PubMed]
6. Li H, Liu DH, Chen LL, Zhao Q, Yu YZ, Ding JJ, Miao LY, Xiao YL, Cai HR, Zhang DP, Guo YB, Xie CM. Meta-analysis of the adverse effects of long-term azithromycin use in patients with chronic lung diseases. Antimicrob Agents Chemother. 2014;58(1):511-7. [CrossRef] [PubMed]
7. Herath SC, Poole P. Prophylactic antibiotic therapy in chronic obstructive pulmonary disease. JAMA. 2014;311(21):2225-6. [CrossRef] [PubMed]
8. Wong C, Jayaram L, Karalus N, Eaton T, Tong C, Hockey H, Milne D, Fergusson W, Tuffery C, Sexton P, Storey L, Ashton T. Azithromycin for prevention of exacerbations in non-cystic fibrosis bronchiectasis (EMBRACE): a randomised, double-blind, placebo-controlled trial. Lancet. 2012;380(9842):660-7. [CrossRef]  [PubMed]
9. Altenburg J, de Graaff CS, Stienstra Y, Sloos JH, van Haren EH, Koppers RJ, van der Werf TS, Boersma WG. Effect of azithromycin maintenance treatment on infectious exacerbations among patients with non-cystic fibrosis bronchiectasis: the BAT randomized controlled trial. JAMA. 2013;309(12):1251-9. [CrossRef] [PubMed] 
10. Serisier DJ, Martin ML, McGuckin MA, Lourie R, Chen AC, Brain B, Biga S, Schlebusch S, Dash P, Bowler SD. Effect of long-term, low-dose erythromycin on pulmonary exacerbations among patients with non-cystic fibrosis bronchiectasis: the BLESS randomized controlled trial. JAMA. 2013;309(12):1260-7. [CrossRef] [PubMed]
11. Brusselle GG, Vanderstichele C, Jordens P, Deman R, Slabbynck H, Ringoet V, Verleden G, Demedts IK, Verhamme K, Delporte A, Demeyere B, Claeys G, Boelens J, Padalko E, Verschakelen J, Van Maele G, Deschepper E, Joos GF. Azithromycin for prevention of exacerbations in severe asthma (AZISAST): a multicentre randomised double-blind placebo-controlled trial. Thorax. 2013 Apr;68(4):322-9. [CrossRef] [PubMed] 
12. Wong EH, Porter JD, Edwards MR, Johnston SL. The role of macrolides in asthma: current evidence and future directions.  Lancet Respir Med. 2014 2:657-70. [CrossRef] [PubMed]
13. Abe S, Nakamura H, Inoue S, Takeda H, Saito H, Kato S, Mukaida N, Matsushima K, Tomoike H. Interleukin-8 gene repression by clarithromycin is mediated by the activator protein-1 binding site in human bronchial epithelial cells. Am J Respir Cell Mol Biol. 2000;22(1):51-60. [CrossRef] [PubMed] 
14. Albert RK, Schuller JL; COPD Clinical Research Network. Macrolide antibiotics and the risk of cardiac arrhythmias. Am J Respir Crit Care Med. 2014;189(10):1173-80. [CrossRef] [PubMed] 
15. Rempe S, Hayden JM, Robbins RA, Hoyt JC. Tetracyclines and pulmonary inflammation. Endocr Metab Immune Disord Drug Targets. 2007;7(4):232-6. [CrossRef] [PubMed] 

Reference as: Robbins RA, Thomas AR, Mathew M. August 2014 Phoenix pulmonary journal club: the use of macrolide antibiotics in chronic respiratory disease. Southwest J Pulm Crit Care. 2014;9(2):130-2. doi: http://dx.doi.org/10.13175/swjpcc109-14 PDF