Azithromycin Compared with Penicillin G Benzathine for Treatment of Incubating Syphilis

Azithromycin Compared with Penicillin G Benzathine for Treatment of Incubating Syphilis

From the University of Alabama at Birmingham School of Medicine and Jefferson County Department of Health, Birmingham, Alabama.

Abstract

Background: Preventive therapy is an important element of syphilis control efforts. No currently recommended, single-dose alternatives to penicillin G benzathine are available for treatment of incubating syphilis.

Objective: To evaluate the use of a single 1.0-g dose of azithromycin for treatment of persons recently exposed to sexual partners with infectious syphilis.

Design: Single-center, open-label, randomized pilot study to compare azithromycin with penicillin G benzathine therapy. Participants were evaluated serologically for 3 months.

Setting: Sexually transmitted disease clinic in Birmingham, Alabama.

Participants: 96 participants who in the preceding 30 days had been exposed to partners with infectious syphilis through sexual intercourse.

Measurements: Syphilis prevention, as indicated by nonreactive serologic tests (rapid plasma reagin and fluorescent treponemal antibody-absorbed), throughout the 3- month follow-up.

Results: Among 96 participants enrolled, none of 40 evaluable persons in the azithromycin group and none of 23 evaluable persons in the penicillin group developed evidence of syphilis. Significantly more penicillin-treated participants (21 of 44 [48%]) than azithromycin-treated participants (12 of 52 [23%]) became nonevaluable during follow-up (P = 0.01).

Conclusion: A single 1.0-g dose of azithromycin seems to be efficacious for prevention of syphilis in persons exposed to infected sexual partners.

Article and Author Information

Grant Support: In part by National Institutes of Allergy and Infectious Diseases grant U19-AI38514 and by donation of medications by Pfizer, Inc., and Ortho-McNeil Pharmaceuticals.
Acknowledgments: The authors thank the disease intervention specialists of the Jefferson County Department of Health for assistance in patient referral and follow-up; Charity M. Richey, MPH, for data management and statistical assistance; and Sharron Hagy for assistance in manuscript preparation.
Requests for Reprints: Edward W. Hook III, MD, Department of Medicine, Division of Infectious Diseases, The University of Alabama at Birmingham, 229 Tinsley Harrison Tower, 1900 University Boulevard, Birmingham, AL 35294-0006.
Current Author Addresses: Dr. Hook: Department of Medicine, Division of Infectious Diseases, The University of Alabama at Birmingham, 229 Tinsley Harrison Tower, 1900 University Boulevard, Birmingham, AL 35294-0006.
Ms. Stephens: Jefferson County Department of Health, 1400 Sixth Avenue, South Birmingham, AL 35233.
Dr. Ennis: Baptist Medical Center, 840 Montclair Road, Suite 317, Birmingham, AL 35213-1944.