title: Long-term effects of azithromycin in patients with cystic fibrosis.
abstract: Low-dose azithromycin has beneficial effects on severity of the lung disease in cystic fibrosis (CF) patients for a period of 6-12 months after initiation of the treatment. Although its impact in the longer term is uncertain, this treatment is frequently used chronically. The aim of this retrospective study was to investigate the effects of low-dose azithromycin treatment on the progression of CF lung disease in patients treated for more than 12 months.
  
  
  
  All of the CF patients followed in our pediatric center and who had been on low-dose azithromycin for more than 12 sequential months were included. The clinical data were collected for one year before and three years after the initiation of the azithromycin treatment. These data comprised lung function analyses, rates of exacerbations and of antibiotic courses, and changes in the airways' bacterial colonization.
  
  
  
  A total of 68 patients were included (mean age: 9.95 yrs (3.61)). After 12 months, significant reductions in the numbers of pulmonary exacerbations and antibiotic courses were present. However, this effect was not maintained in the subsequent periods, during which increased rates of both pulmonary exacerbations and antibiotic courses were observed. The lung function decline was not modified during the treatment, and a decreasing time-dependent trend typical of CF was observed for the various parameters. No differences in the airway colonization by pathogens such as Pseudomonas aeruginosa and methicillin-sensitive and/or -resistant Staphyloccocus aureus were observed during the treatment. However, isolated Staphyloccocus aureus strains became resistant to macrolides after 6 months of azithromycin and remained resistant thereafter.
  
  
  
  No clinical benefits of low-doses azithromycin were present after one year of treatment in young CF patients. Selection for macrolide-resistant strains of bacteria occurred, which should lead to a reconsideration of the duration of azithromycin treatment in CF.
authors: AP-HP, Hôpital Trousseau, Pediatric Pulmonology Department, Paris, France; Besançon Hospital, Pediatric Department, Besançon, France.
authors: Clémentine
authors: C
authors: Samson
authors: AP-HP, Hôpital Trousseau, Pediatric Pulmonology Department, Paris, France.
authors: Aline
authors: A
authors: Tamalet
authors: AP-HP, Hôpital Trousseau, Bacteriology Department, Paris, France.
authors: Hoang Vu
authors: HV
authors: Thien
authors: AP-HP, Hôpital Trousseau, Pediatric Pulmonology Department, Paris, France; INSERM, Centre de Recherche Saint-Antoine (CRSA), F-75012, Paris, France.
authors: Jessica
authors: J
authors: Taytard
authors: AP-HP, Hôpital Trousseau, Pediatric Pulmonology Department, Paris, France.
authors: Caroline
authors: C
authors: Perisson
authors: AP-HP, Hôpital Trousseau, Pediatric Pulmonology Department, Paris, France.
authors: Nadia
authors: N
authors: Nathan
authors: AP-HP, Hôpital Trousseau, Pediatric Pulmonology Department, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, Paris, France.
authors: Annick
authors: A
authors: Clement
authors: Sorbonne Universités, UPMC Univ Paris 06, Paris, France; AP-HP, Hôpital Saint Antoine, Biostatistic Department, INSERM U1136, Paris, France.
authors: Pierre-Yves
authors: PY
authors: Boelle
authors: AP-HP, Hôpital Trousseau, Pediatric Pulmonology Department, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, Paris, France; INSERM, Centre de Recherche Saint-Antoine (CRSA), F-75012, Paris, France. Electronic address: harriet.corvol@aphp.fr.
authors: Harriet
authors: H
authors: Corvol
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000008:administration & dosage / Q000494:pharmacology*; D002648:Child; D003550:Cystic Fibrosis / Q000188:drug therapy* / Q000503:physiopathology; D018450:Disease Progression; D024881:Drug Resistance, Bacterial; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology; D018942:Macrolides / Q000627:therapeutic use; D008297:Male; D011552:Pseudomonas Infections / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012129:Respiratory Function Tests; D012137:Respiratory System / Q000187:drug effects / Q000382:microbiology; D012189:Retrospective Studies; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D017963:Azithromycin
keywords: Azithromycin; Bacteria resistance; Children; Cystic fibrosis; Lung function; Respiratory exacerbation