A single 2 g oral dose of extended-release azithromycin for treatment of gonococcal urethritis.
OBJECTIVES
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.


PATIENTS AND 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.
['Yasuda|Mitsuru|M|', 'Ito|Shin|S|', 'Kido|Akira|A|', 'Hamano|Kiminari|K|', 'Uchijima|Yutaka|Y|', 'Uwatoko|Noriyasu|N|', 'Kusuyama|Hiroyuki|H|', 'Watanabe|Akiko|A|', 'Miyamura|Ryuzou|R|', 'Miyata|Kazutoyo|K|', 'Deguchi|Takashi|T|']
D000284:Administration, Oral D000293:Adolescent D000328:Adult D000900:Anti-Bacterial Agents D017963:Azithromycin D003692:Delayed-Action Preparations D006069:Gonorrhea D006801:Humans D008297:Male D008875:Middle Aged D009344:Neisseria gonorrhoeae D011446:Prospective Studies D016896:Treatment Outcome D014526:Urethritis D055815:Young Adult
azithromycin-SR Neisseria gonorrhoeae male urethritis