Syphilis Response to Higher Penicillin Dosage: The 2.4 Versus 7.2 Study

Syphilis remains a significant health problem worldwide, with an estimated 10.6 million new cases per year. Due to shared transmission route and risk factors, co-infection with syphilis and Human Immunodeficiency Virus (HIV) is not uncommon. Several studies have evaluated the response to syphilis treatment in HIV-infected patients. They support the claim that patients with HIV have a slower decrease in syphilis antibody titers, and that they may progress to neurosyphilis in earlier stages.

The Center for Disease Control and Prevention's Sexually Transmitted Disease Treatment Guidelines has advocated treating HIV-infected patients who have primary, secondary syphilis or early latent syphilis with the same doses of penicillin as for HIV-uninfected patients (single dose of 2.4 million units of benzathine penicillin G). The investigators designed a randomized controlled trial in order to compare the efficacy of three- versus single-dosed regimens of intramuscular benzathine penicillin G (BPG) for the treatment of early syphilis in HIV-infected patients.

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Key information

Conditions

Syphilis Bacterial Infections Bacterial Infections and Mycoses Communicable Diseases Genital Diseases Gram-Negative Bacterial Infections Infections Sexually Transmitted Diseases Sexually Transmitted Diseases, Bacterial Spirochaetales Infections Treponemal Infections Urogenital Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

About this study

The investigators conducted a prospective, randomized, open label study at three clinical sites including Thomas Street Health Center and North West Clinic (Harris Health System), and the Michael E. DeBakey Veterans Affairs Medical Center in Houston, Texas. After obtaining written informed consent, the investigators randomly assigned patients to either a single intramuscular injection of 2.4 million units of BPG (standard therapy) or three doses (enhanced therapy) of intramuscular BPG administered weekly (a total of 7.2 million units).

Patients were eligible for inclusion in the study if they were 18 years of age or older and had a diagnosis of HIV. The diagnosis of syphilis was made based on a positive Rapid Plasma Reagin (RPR) and treponema pallidum particle agglutination tests. Patients with primary, secondary and early latent syphilis were included.

Exclusion criteria

were history of penicillin allergy, diagnosis of late latent syphilis, neurosyphilis, and antibiotic use with significant activity against Treponema pallidum within the preceding two weeks.

Follow-up period was 12 months. Serum samples were obtained at initial visit and follow-up visits every 3 months for serological testing for syphilis. Treatment success was defined as a decrease in RPR titer of >= 2 dilutions (4-fold) from the initial RPR titer during the follow-up period.

Both intention-to-treat and per-protocol analyses were performed

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Diagnosed with HIV by ELISA and confirmed by Western blot
Positive Rapid Plasma Reagin and treponema pallidum particle agglutination tests

Exclusion criteria

History of penicillin allergy
Diagnosis of late latent syphilis
Diagnosis of neurosyphilis
Antibiotic use with significant activity against Treponema pallidum within the preceding two weeks

Treatment and study plan

Benzathine penicillin G intramuscular 7.2 million units

Drug

Three doses of intramuscular 2.4 million units of benzathine penicillin G administered weekly (a total of 7.2 million units).

Other names: Enhanced therapy

Benzathine penicillin G intramuscular 2.4 million units

Drug

A single dose of intramuscular 2.4 million units of benzathine penicillin G

Other names: Standard therapy

Primary outcomes

Treatment Success Defined as a Decrease in Rapid Plasma Reagin (RPR) Titer of >= 2 Dilutions (4-fold)

Time frame: 12 months

Number of participants who achieve treatment success. Loss to follow-up was assumed to be a failure.

Sponsors and collaborators

Lead sponsor

Baylor College of Medicine

Other

Registry information

Official study title

Syphilis Response to Higher Penicillin Dosage in HIV Co-Infected Patients

Important dates

Study start: 2008
Primary completion: 2012
Study completion: 2012
First posted: Nov 23, 2015
Registry last updated: May 17, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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