2025-525150-19-01RecruitingPhase 4
Influence of Doxycycline Use as Prophylaxis for Sexually Transmitted Infections on Bacterial Resistance and Gut Microbiota: MiDoxyR-PEP Study
Source: EU CTIS (euclinicaltrials.eu) · Last updated 4 Nov 2026
Brief summary (registry, in English)
To study the impact of post-exposure prophylaxis with doxycycline (doxyPEP) among MSM and transgender women on the incidence of nasal colonization by Staphylococcus aureus with resistance mechanisms, the incidence of sexually transmitted infections (STIs), and to assess changes in gut microbiota following the initiation of doxyPEP in this population.
- Status (registry)
- Recruiting
- Phase (registry)
- Phase 4
- Study type
- Interventional
- Enrollment
- 392 (estimated)
- First submitted
- 3 Jun 2026
- Start date
- 1 Sept 2026
- Lead sponsor
- Instituto De Investigacion Marques De Valdecilla
- Diseases
- HIV
- EU CT number
- 2025-525150-19-01
What you commit to
- Study type: Interventional · Phase 4
- Planned participants: 392
- 5 sites in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of EU CTIS (euclinicaltrials.eu). It describes the study design.
AI-kivonat: who the study is looking for
Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults who are men who have sex with men (MSM) or transgender women, and who use PrEP or live with HIV. They must also have at least two risk factors for sexually transmitted infections.
- Age
- 18 years or older
- Sex
- Men who have sex with men and transgender women (the record lists the sex as male)
- Earlier treatment
- PrEP users must have been on treatment for at least 3 months. People living with HIV must have been on active antiretroviral therapy for at least 3 months.
- Biomarker or test result
- People living with HIV must not have a detectable viral load.
Main reasons for not taking part
- Under 18 years old
- Long-term antimicrobial treatment, other than antiretroviral therapy or prophylaxis
- Taking part in another study that uses antimicrobials
- Allergy or intolerance to tetracyclines
- PrEP for less than 3 months, or HIV with a detectable viral load or antiretroviral therapy for less than 3 months
Read by machine on 9 Nov 2026.
Who cannot take part
Copied verbatim from EU CTIS (euclinicaltrials.eu) and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Patients who are receiving long-term antimicrobial therapy, other than antiretroviral therapy or prophylaxis.
Other illness
- PrEP users who have been on treatment for less than 3 months, or people living with HIV who have a detectable viral load or have been on active antiretroviral therapy for less than 3 months.
- Patients with an allergy or intolerance to tetracyclines
Age
- Patients under the age of 18.
Other
- Participation in another study involving the use of antimicrobials.
Who the study is looking for
- Adult patients (18 years of age or older) who are MSM and transgender women, PrEP users, or people living with HIV.
- Who have at least two of the following risk factors for contracting STIs, based on the recommendations of the Ministry of Health
- More than 10 different sexual partners in the past year
- Engaging in anal sex without a condom at least once in the past year
- Drug use associated with having unprotected sex at least once in the past year.
- Administration of post-exposure prophylaxis on more than one occasion in the past year.
- Informed Consent Form
Age in the registry: 18 years to - · Sex: Male · Does not accept healthy volunteers
Sites (5)
Sites in registry order. Save your city in your profile to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Hospital Universitario San Agustin | aviles | Spain | Recruiting |
| Hospital Universitario De Leon | León | Spain | Recruiting |
| Hospital Universitario Central De Asturias | Oviedo | Spain | Recruiting |
| Hospital Universitario De Salamanca | Salamanca | Spain | Recruiting |
| Hospital Universitario Marqués de Valdecilla | Santander | Spain | Recruiting |
This page is information, not medical advice. Discuss any trial with your doctor.