title: Comparison of serological responses to single-dose azithromycin (2 g) versus benzathine penicillin G in the treatment of early syphilis in HIV-infected patients in an area of low prevalence of macrolide-resistant Treponema pallidum infection.
abstract: OBJECTIVE
  Effectiveness of single-dose azithromycin (2 g) in the treatment of early syphilis among HIV-infected patients has rarely been evaluated in the era of combination ART.
  
  
  METHODS
  Consecutive HIV-infected patients with early syphilis, who received 2 g single-dose azithromycin or 2.4 MU benzathine penicillin G, between 2007 and 2014, were prospectively observed. Genotypic resistance to macrolides was determined in Treponema pallidum isolates identified from clinical specimens using PCR assays. Rapid plasma reagin (RPR) titres were determined at baseline and every 3 months after treatment. Primary outcome was a decline of RPR titre by ≥4-fold at 12 months after treatment.
  
  
  RESULTS
  During the study period, 162 HIV-infected patients with early syphilis received benzathine penicillin G and 237 patients received azithromycin. At 12 months follow-up, the serological response rate for penicillin and azithromycin groups was 61.1% and 56.5% (P = 0.41), respectively; respective response rate was 61.1% and 65.9% (P = 0.49) if we only included patients infected with T. pallidum not harbouring macrolide resistance in the azithromycin group. In multivariate analysis, RPR titres ≥1:32 (OR 2.56; 95% CI 1.55-4.21) and prior syphilis (OR 0.54; 95% CI 0.35-0.81) were predictors of serological response. Most common adverse effects of azithromycin included diarrhoea (52.7%), nausea (22.4%), abdominal pain (18.6%), bloating (17.7%) and lassitude/somnolence (27.4%).
  
  
  CONCLUSIONS
  In the setting of a low prevalence of macrolide-resistant T. pallidum, 2 g single-dose azithromycin achieved a similar serological response to benzathine penicillin G in HIV-infected patients with early syphilis. Major adverse effects of azithromycin were gastrointestinal symptoms and lassitude/somnolence.
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chia-Jui
authors.initials: CJ
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan Department of Health and Nutrition, Chia Nan University of Pharmacy and Sciences, Tainan, Taiwan.
authors.forename: Hung-Jen
authors.initials: HJ
authors.lastname: Tang
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Sui-Yuan
authors.initials: SY
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Szu-Min
authors.initials: SM
authors.lastname: Hsieh
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan.
authors.forename: Kuan-Yeh
authors.initials: KY
authors.lastname: Lee
authors.affiliation: School of Medicine, Chung Shan Medical University and Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Yuan-Ti
authors.initials: YT
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan Center of Infection Control, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wang-Huei
authors.initials: WH
authors.lastname: Sheng
authors.affiliation: Center of Infection Control, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Shang-Ping
authors.initials: SP
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan Department of Medical Research, China Medical University Hospital, Taichung, Taiwan China Medical University, Taichung, Taiwan hcc0401@ntu.edu.tw.
authors.forename: Chien-Ching
authors.initials: CC
authors.lastname: Hung
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Shan-Chwen
authors.initials: SC
authors.lastname: Chang
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D017963:Azithromycin / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D005260:Female; D005767:Gastrointestinal Diseases / Q000139:chemically induced / Q000453:epidemiology / Q000473:pathology; D005838:Genotype; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D018942:Macrolides / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010401:Penicillin G Benzathine / Q000627:therapeutic use*; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D011935:Reagins / Q000097:blood*; D013587:Syphilis / Q000188:drug therapy*; D016896:Treatment Outcome; D014210:Treponema pallidum / Q000187:drug effects* / Q000235:genetics; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D011935:Reagins; D017963:Azithromycin; D010401:Penicillin G Benzathine