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Azithromycin/Bicillin Syphilis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00031499
Recruitment Status : Completed
First Posted : March 7, 2002
Last Update Posted : April 29, 2013
Information provided by (Responsible Party):
National Institute of Allergy and Infectious Diseases (NIAID)

Brief Summary:
The purpose of this study is to determine if azithromycin, a drug approved for treatment of other infections, is as effective for syphilis (a sexually transmitted disease) as the standard treatment. Approximately 600 healthy adults, who are HIV-negative, ages 18 to 55 years of age, with primary, secondary or early latent syphilis, will participate in this research study. Volunteers will be enrolled in 5 U.S. cities and in Madagascar. Participants will be chosen randomly (by chance) to receive 1 of 2 study drugs: benzathine penicillin given (2 shots in the buttocks) or 4 tablets of azithromycin. Subjects who report a history of a penicillin allergy will be given either 2.0 g of oral azithromycin or 100 mg doxycycline taken orally, twice a day for 14 days. Over 2 years, 10 visits will be required. Procedures will include blood samples, physical exams, and swabs of sores.

Condition or disease Intervention/treatment Phase
Syphilis Drug: Azithromycin Drug: Benzathine Penicillin Drug: Doxycycline Phase 3

Detailed Description:
Syphilis is a disease with a worldwide distribution. It causes genital ulceration, thereby amplifying risk for HIV acquisition and transmission and it may cause congenital infection, spontaneous abortion, and stillbirth if untreated in pregnant women. About one third of all cases, if untreated, result in late sequelae which include neurosyphilis, gumma formation and cardiovascular involvement. This study will be a multi-center, randomized, open-label trial to evaluate the efficacy of azithromycin in treating primary, secondary and early latent syphilis in HIV (Human Immunodeficiency Virus) uninfected volunteers. Up through version 6.0 of this protocol volunteers were only followed for 12 months. The protocol was amended starting with version 7.0 to include follow-up visits at month 18 and 24 in order to capture possible "late failures." Each subject will be randomized into a treatment group. If the subject does not have a self-reported history of penicillin allergy, the subject will be randomized to receive either a single 2.0 gram dose of azithromycin administered orally, or 2.4 million units of benzathine penicillin G administered intramuscularly once. Eligible patients who report a history of penicillin allergy will be randomized (using a separate randomization schedule) to receive either a single dose of azithromycin or doxycycline, 100 milligrams, taken orally, twice a day for 14 days. Block randomization will be used within each clinical center with subjects allocated in equal numbers to either standard therapy or azithromycin. Participants found to be ineligible for study participation after they have been randomized and treated, will be treated again with benzathine penicillin G (or doxycycline if they are allergic to penicillin) and will continue follow-up for safety evaluation. The treatment assignments will not be blinded. No attempt will be made to recruit a sufficient sample size among penicillin allergic subjects to attain the desired power for the primary outcome. Therefore these results will be seen as preliminary to a possible future trial and as confirmatory to the primary comparison. Although the study endpoint will be determined at 6 months, all participants, will have follow-up visits for 2 full years. At the end of the 6 month evaluation period, all participants will have been classified in one of the following groups: cure; clinical response/serological nonresponse; or failure.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 593 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Phase III Equivalence Trial of Azithromycin vs. Benzathine Penicillin for the Treatment of Early Syphilis
Study Start Date : June 2000
Actual Primary Completion Date : August 2007
Actual Study Completion Date : March 2009

Arm Intervention/treatment
Experimental: Azithromycin
Azithromycin 2.0 gram single oral dose.
Drug: Azithromycin
Single 2 gram oral dose (4 tablets) at Day 1.

Active Comparator: Benzathine Penicillin
Benzathine penicillin 2.4 million units administered intramuscularly. Doxycycline will be administered if the patient is allergic to Benzathine Penicillin.
Drug: Benzathine Penicillin
Supplied in pre-filled syringes containing 1.2 million units of benzathine penicillin; 2.4 million units administered intramuscularly at Day 1, in one or both buttocks.

Drug: Doxycycline
Baseline visit, 28 capsules dispensed, for a dose of 100 mg twice a day (BID).

Primary Outcome Measures :
  1. Cure of syphilis defined as a negative reactive serologic test for syphilis (RPR) titer or greater than or equal to a 4-fold (2 dilution) decrease in RPR titer at 6 months following treatment and resolution of all signs and symptoms of syphilis. [ Time Frame: Month 6. ]

Secondary Outcome Measures :
  1. Cure rates at 9, 12 and 24 months post treatment and the rate of relapse or reinfection defined as cure followed by recurrent clinical manifestations or a 2-dilution increase in RPR titer over previous lowest result. [ Time Frame: Months 9, 12, and 24. ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • The subject is 18 to 55 years of age.
  • The subject has signed written informed consent.
  • The subject has untreated primary [darkfield or Treponema (T.) pallidum by a rapid, direct, fluorescent antibody darkfield (DFA-TP)] positive genital ulcers, secondary (based on classical palmar/plantar rash, condylomata lata, mucous patches, etc. or darkfield or DFA-TP positive lesions), or early latent syphilis (e.g., current reactive serologic tests for syphilis (STS), and a documented non-reactive STS or documented sexual exposure to a known early latent, primary or secondary syphilis patient in last 12 months; identification of this sexual contact must occur within 60 days of admission into the study).
  • The subject has laboratory evidence of syphilis, i.e., reactive serologic test for syphilis (RPR).
  • The subject is not pregnant, as documented by a negative urine or serum pregnancy test, or lactating.
  • The subject is willing to have an HIV test, and, participate in HIV counseling and return to the clinic for follow-up treatment.

Exclusion Criteria:

  • The subject does not have reactive serologic tests for syphilis.
  • The subject has latent syphilis of unknown duration, late latent syphilis or evidence of neurosyphilis.
  • The subject has a known or suspected allergy to macrolide or azalide antibiotics.
  • The subject has a known or suspected sexually transmitted disease (STD), other than syphilis requiring treatment with a drug, other than azithromycin, active against T. pallidum.
  • The subject has used antibiotics active against T. pallidum in the preceding 30 days. (Note: the use of antimicrobials known to NOT be effective against T. pallidum such as quinolones, sulfonamides, trimethoprim, metronidazole and spectinomycin will be allowed).
  • The subject is known to be HIV positive prior to enrollment.
  • The subject has suspected or known ongoing drug use that might interfere with study participation and follow-up treatment.
  • The subject has a history of cardiovascular disease, known immunosuppression, or known AIDS, which might compromise response to therapy.
  • The subject is judged by the investigators to be unlikely to reliably participate in the study follow-up.
  • The subject has used any investigational drugs in the past 30 days.
  • The subject has any other condition that may impair drug absorption (malabsorption syndrome or active peptic ulcer disease).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00031499

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United States, Alabama
University of Alabama Hospital - Infectious Diseases
Birmingham, Alabama, United States, 35249-0001
United States, Indiana
Indiana University
Indianapolis, Indiana, United States, 46202
United States, Louisiana
Louisiana State University Health Sciences Center - Infectious Diseases
New Orleans, Louisiana, United States, 70112-2865
United States, Maryland
Johns Hopkins Hospital - Medicine - Infectious Diseases
Baltimore, Maryland, United States, 21287-0005
United States, North Carolina
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, United States, 27514
University of North Carolina School of Medicine - Center for Infectious Diseases
Chapel Hill, North Carolina, United States, 27599-7030
Durham County Health Department
Durham, North Carolina, United States, 27701-3720
Laboratoire National de Reference sur le VIH/SIDA (LNR)
Analamanga, Antananarivo, Madagascar, 101
Hopitaly Kely
Tamatave, Antsiranana, Madagascar
Hopitaly Mahabibo
Mahajanga Majunga, Mahajanga, Madagascar, 401
Sponsors and Collaborators
National Institute of Allergy and Infectious Diseases (NIAID)
Publications of Results:
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Responsible Party: National Institute of Allergy and Infectious Diseases (NIAID) Identifier: NCT00031499    
Other Study ID Numbers: 99-005
First Posted: March 7, 2002    Key Record Dates
Last Update Posted: April 29, 2013
Last Verified: April 2013
Keywords provided by National Institute of Allergy and Infectious Diseases (NIAID):
Azithromycin, Syphilis, Penicillin
Additional relevant MeSH terms:
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Treponemal Infections
Spirochaetales Infections
Gram-Negative Bacterial Infections
Bacterial Infections
Bacterial Infections and Mycoses
Sexually Transmitted Diseases, Bacterial
Sexually Transmitted Diseases
Communicable Diseases
Penicillin G Benzathine
Penicillin G
Penicillin G Procaine
Anti-Bacterial Agents
Anti-Infective Agents
Antiprotozoal Agents
Antiparasitic Agents