Daily Doxycycline for Early Syphillis
ConditionSyphilis
Trial statusRecruiting
Trial phasePhase 2
Trial typeInterventional
Biological sexAll
Age18+
SponsorUniversity of Washington
About this trial
The goal of this clinical trial is to learn if doxycycline taken as 200mg daily for 14 days is effective to treat early stage syphilis. This is different from how doxycycline is typically used for syphilis because the full doxycycline dose will be taken at the same time of day, rather than split up into a twice daily regimen. Lab data support that taking the medication as a single daily dose should be effective as treatment, but it has not been studied clinically. The main question this study aims to answer is:
Is doxycycline taken as a single daily dose of 200mg for 14 days an effective treatment for early syphilis based on a combined outcome of clinical improvement and blood test improvement?
Participants will:
1. Take doxycycline 200mg daily for 14 days 2. Submit oral and rectal swabs that test for syphilis bacteria every other day for 2 weeks, returned by mail 3. Complete 2 brief online surveys over the first 2 weeks 4. Return to the clinic for an interview and blood draw every 3 months for a maximum of 3 study visits, including the first visit
The investigators will compare the percentage of participants in the study who have response to treatment by 6 months to that of persons who have received standard (CDC-recommended) regimens. To do this, the investigators will calculate response percentage estimates following a shot of long-acting penicillin or 14 days of doxycycline 100mg twice daily from 60-person samples from the sexual health program's records.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Clinical diagnosis of primary syphilis (based on the presence of a chancre) and either a positive qualitative RPR in the absence of a prior positive RPR on their most recent serological test for syphilis or a positive darkfield microscope exam of material taken from a chancre, OR
Clinical diagnosis of secondary syphilis with a positive qualitative RPR in the absence of a prior positive RPR on their most recent serological test for syphilis, OR
A laboratory-confirmed diagnosis of early latent syphilis within one month (i.e. <31 days prior).
Disqualifiers
age under 18
persons with evidence of neurosyphilis (including ocular and otic syphilis) or tertiary syphilis
persons who are unable to give informed consent
persons deemed by the study investigators to be unable to complete study follow-up visits
Trial design
Design model
Single group
Treatments tested in this trial
Doxycycline 200mg daily for 14 days
DrugDoxycycline will be taken as a single dose of 200mg daily, rather than the current CDC-recommended 100mg twice daily regimen for early syphilis. The duration will still be 14 days of therapy.
Treatment groups
15 Participants
are divided into 1 treatment groupGroup A: Doxycycline 200mg daily for 14 daysExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Composite clinical and serological response
Clinical response and serological response will be aggregated to arrive at one reported value, a binary outcome of "yes" (1) or "no" (0). Clinical response equates to resolution of clinical symptoms of syphilis the participants presented with, such as rash or chancre, without the development of new symptoms of syphilis. Resolution will be marked as "yes" or "no". Serological response equates to a fourfold decrease in RPR compared to the presenting RPR titer by 6 months. Resolution will be marked as "yes" or "no". Thus, to generate the composite response outcome, participants with outcomes of "yes" for both clinical response and serological response will qualify as a binary outcome of "yes" (1) . Participants who do not have outcomes of "yes" for both clinical response and serological response will qualify as a binary outcome of "no" (0).
Time frame
6 monthsSponsors and contacts
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Source ClinicalTrials.gov