title: A single 2 g oral dose of extended-release azithromycin for treatment of gonococcal urethritis.
abstract: OBJECTIVE
  We treated gonococcal urethritis in men with a single 2 g dose of azithromycin extended-release formulation (azithromycin-SR) to determine its microbiological outcomes and tolerability.
  
  
  METHODS
  We enrolled 189 Japanese men with gonococcal urethritis between April 2009 and December 2013. The patients were given a single 2 g dose of azithromycin-SR. Microbiological efficacy was evaluated by the results of the post-treatment molecular testing of Neisseria gonorrhoeae. MIC testing was performed only for pretreatment isolates of N. gonorrhoeae collected from the patients.
  
  
  RESULTS
  We evaluated 130 patients for microbiological outcomes. Of these patients, 122 (93.8%) were judged to be microbiologically cured on the basis of negative test results. All isolates for which the azithromycin MICs were ≤0.25 mg/L were eradicated, whereas 5 of 12 isolates for which the MICs were 1 mg/L persisted after the treatment. Forty-six adverse events occurred in 41 patients. However, all adverse events were classified as mild.
  
  
  CONCLUSIONS
  The eradication rate of N. gonorrhoeae was 93.8% in men with gonococcal urethritis treated with a single 2 g dose of azithromycin-SR. The breakpoint MIC of a 2 g dose of azithromycin-SR for gonococcal urethritis associated with clinical treatment failures appeared to be 1 mg/L. With regard to side effects of higher doses of azithromycin, the 2 g dose of azithromycin-SR appeared to improve tolerability. However, the widespread use of a high-dose regimen of azithromycin might lead to the development of further resistance to azithromycin.
authors.affiliation: Department of Urology, Gifu University Hospital, Gifu, Japan super7@gifu-u.ac.jp.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Yasuda
authors.affiliation: iClinic, Sendai, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Ito
authors.affiliation: Urological Infection Study Group in West Saitama, Saitama, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kido
authors.affiliation: Urological Infection Study Group in West Saitama, Saitama, Japan.
authors.forename: Kiminari
authors.initials: K
authors.lastname: Hamano
authors.affiliation: Urological Infection Study Group in West Saitama, Saitama, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Uchijima
authors.affiliation: Urological Infection Study Group in West Saitama, Saitama, Japan.
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Uwatoko
authors.affiliation: Urological Infection Study Group in West Saitama, Saitama, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusuyama
authors.affiliation: Urological Infection Study Group in West Saitama, Saitama, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Watanabe
authors.affiliation: Urological Infection Study Group in West Saitama, Saitama, Japan.
authors.forename: Ryuzou
authors.initials: R
authors.lastname: Miyamura
authors.affiliation: Urological Infection Study Group in West Saitama, Saitama, Japan.
authors.forename: Kazutoyo
authors.initials: K
authors.lastname: Miyata
authors.affiliation: Department of Urology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Deguchi
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D017963:Azithromycin / Q000008:administration & dosage*; D003692:Delayed-Action Preparations / Q000008:administration & dosage; D006069:Gonorrhea / Q000175:diagnosis / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009344:Neisseria gonorrhoeae / Q000187:drug effects* / Q000302:isolation & purification; D011446:Prospective Studies; D016896:Treatment Outcome; D014526:Urethritis / Q000175:diagnosis / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D017963:Azithromycin
keywords: Neisseria gonorrhoeae; azithromycin-SR; male urethritis