Pharmacokinetic Characterization of a Single 200 mg Dose of Doxycycline in Post-exposure Prophylaxis (PEP) of Sexually Transmitted Infections in Different Biological Compartments

Study Overview
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Brief Summary
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Post-exposure prophylaxis (PEP) using doxycycline 200 mg within 24 hours of unprotected sexual intercourse to prevent sexually transmitted infections has demonstrated a reduction in the incidence of chlamydial and syphilis infections and syphilis infection by 70% and 73% in men who have sex with men (MSM) undergoing pre-exposure prophylaxis prophylaxis (PrEP) for HIV. Other studies are underway or in development on doxycycline prophylaxis for bacterial STIs, which are particularly common in this population. Monitoring adherence to PEP is of great interest in guaranteeing the effectiveness of this strategy and to be able to assess the uptake of PEP among PrEP users. Among the many methods for assessing adherence, measuring drug concentrations is a more accurate measure of adherence than self-reporting. The therapeutic monitoring of doxycycline and the assessment of adherence have been described using plasma and hair samples, allowing estimation of intake over the last 3-4 days and 4 months, respectively. Nevertheless, these biological matrices present several limitations for application in clinical practice: reflecting the duration of exposure should be more in line with the frequency of visits (2 months), and the collection of hair samples may be difficult due to refusal or short hair. On the other hand, interpretation of the hair assay is limited by the degradation of doxycycline in this matrix, which could lead to underestimation of drug intake. By Therefore, new biological matrices are needed for more accurate assessment of doxycycline adherence in post-exposure prevention monitoring. The objective is to evaluate the pharmacokinetics of doxycycline in plasma, whole blood, dried blood spots (DBS), urine and hair after a single dose of doxycycline in men using oral doxycycline for post-exposure prophylaxis of sexually transmitted infections (syphilis or Chlamydia trachomatis) and having sex with men.

Official Title
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Caractérisation de la pharmacocinétique d'Une Dose Unique de 200 mg de Doxycycline en Prophylaxie Post-exposition (PEP) Des Infections Sexuellement Transmissibles Dans différents Compartiments Biologiques

Conditions
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Post-exposure Prophylaxis, Sexually Transmitted Diseases, Doxycycline

Intervention / Treatment
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* Other: Samples


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult male patient Men who have Sex with Men (MSM) on PrEP regularly taking doxycycline for Sexually Transmitted Infections (STI) prevention Has not taken doxycycline for at least 3 months No symptoms of bacterial STI infection (chlamydia, gonorrhea, Mycoplasma genitalium or syphilis). Documented history of bacterial STI infection within the past 12 months Having had a risky intercourse within 24 hours and at the latest within 72 hours and for which a prescription of doxycycline in a single dose of 200 mg has been made within the framework of his usual follow-up. Free, informed, written consent, signed by the person and the investigator at the latest on the day of inclusion and before any examination carried out within the framework of the study (article L1122-1-1 of the Public Health Code). Person affiliated or benefiting from a social security system (article L1121-11 of the Public Health Code) Exclusion Criteria: Systemic treatment with retinoids (Acnetrait®, Procuta®, Curacné®, Contracné®, ....). Treatment with enzyme-inducing anticonvulsants (carbamazepine, phenobarbital, phenytoin, etc.). Known allergy to antibiotics of the tetracycline family. Known allergy to one of the components of doxycycline tablets. Documented esophageal injury Ongoing treatment with doxycycline at the time of inclusion. Person participating in another research study with an exclusion period still in progress at inclusion. Persons under guardianship, conservatorship, or deprived of liberty by judicial or administrative decision. Patients on State Medical Aid

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Adult male patient<br>Men having Sex with Men on PrEP (pre-Exposition Prophylaxy) regularly taking doxycycline for Sexually Transmitted Infection (STI) prevention | Other: Samples<br>* Blood samples, urine samples and oropharyngeal swabs before taking 200mg of doxycycline and then 2h, 24h, 48h, 7 days, 14 days, 60 days and 90 days after the single dose of doxycycline Hair samples: at the time of doxycycline administration, 1 month and 3 months after the single dose of doxycycline<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Concentration of doxycycline in urine |  | At Day 90 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Concentration of doxycyline in plasma |  | Before the single intake of doxycycline | 
| Concentration of doxycyline in plasma |  | 2 hours after doxycycline intake | 
| Concentration of doxycyline in plasma |  | 24 hours after doxycycline intake | 
| Concentration of doxycyline in plasma |  | 48 hours after doxycycline intake | 
| Concentration of doxycyline in plasma |  | 7 days after doxycycline intake | 
| Concentration of doxycyline in plasma |  | 14 days after doxycycline intake | 
| Concentration of doxycyline in plasma |  | 30 days after doxycycline intake | 
| Concentration of doxycyline in plasma |  | 60 days after doxycycline intake | 
| Concentration of doxycyline in plasma |  | 90 days after doxycycline intake | 
| Concentration of doxycyline in whole blood |  | Before the single intake of doxycycline | 
| Concentration of doxycyline in whole blood |  | 2 hours after doxycycline intake | 
| Concentration of doxycyline in whole blood |  | 24 hours after doxycycline intake | 
| Concentration of doxycyline in whole blood |  | 48 hours after doxycycline intake | 
| Concentration of doxycyline in whole blood |  | 7 days after doxycycline intake | 
| Concentration of doxycyline in whole blood |  | 14 days after doxycycline intake | 
| Concentration of doxycyline in whole blood |  | 30 days after doxycycline intake | 
| Concentration of doxycyline in whole blood |  | 60 days after doxycycline intake | 
| Concentration of doxycyline in whole blood |  | 90 days after doxycycline intake | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | Before the single intake of doxycycline | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | 2 hours after doxycycline intake | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | 24 hours after doxycycline intake | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | 48 hours after doxycycline intake | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | 7 days after doxycycline intake | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | 14 days after doxycycline intake | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | 30 days after doxycycline intake | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | 60 days after doxycycline intake | 
| Concentration of doxycyline in Dried Blood Spot (DBS) |  | 90 days after doxycycline intake | 
| Concentration of doxycyline in urine |  | Before the single intake of doxycycline | 
| Concentration of doxycyline in urine |  | 2 hours after doxycycline intake | 
| Concentration of doxycyline in urine |  | 24 hours after doxycycline intake | 
| Concentration of doxycyline in urine |  | 48 hours after doxycycline intake | 
| Concentration of doxycyline in urine |  | 7 days after doxycycline intake | 
| Concentration of doxycyline in urine |  | 14 days after doxycycline intake | 
| Concentration of doxycyline in urine |  | 30 days after doxycycline intake | 
| Concentration of doxycyline in urine |  | 60 days after doxycycline intake | 
| Concentration of doxycycline in oropharyngeal secretions |  | Before the single intake of doxycycline | 
| Concentration of doxycycline in oropharyngeal secretions |  | 2 hours after doxycycline intake | 
| Concentration of doxycycline in oropharyngeal secretions |  | 24 hours after doxycycline intake | 
| Concentration of doxycycline in oropharyngeal secretions |  | 48 hours after doxycycline intake | 
| Concentration of doxycycline in oropharyngeal secretions |  | 7 days after doxycycline intake | 
| Concentration of doxycycline in oropharyngeal secretions |  | 14 days after doxycycline intake | 
| Concentration of doxycycline in oropharyngeal secretions |  | 30 days after doxycycline intake | 
| Concentration of doxycycline in oropharyngeal secretions |  | 60 days after doxycycline intake | 
| Concentration of doxycycline in oropharyngeal secretions |  | 90 days after doxycycline intake | 
| Doxycycline concentration in hair |  | Before the single intake of doxycycline | 
| Doxycycline concentration in hair |  | 1 month after doxycycline intake | 
| Doxycycline concentration in hair |  | 3 months after doxycycline intake | 
| Number of biological matrix(es) associated with a quantifiable doxycycline dosage | Determine the biological matrix(es) associated with a quantifiable doxycycline dosage in more than 90% of the samples collected during the study. | Up to 15 days | 
| Number of biological matrix(es) associated with a quantifiable doxycycline dosage | Determine the biological matrix(es) associated with a quantifiable doxycycline dosage in more than 90% of the samples collected during the study. | Up to 30 days | 
| Number of biological matrix(es) associated with a quantifiable doxycycline dosage | Determine the biological matrix(es) associated with a quantifiable doxycycline dosage in more than 90% of the samples collected during the study. | Up to 60 days | 
| Number of biological matrix(es) associated with a quantifiable doxycycline dosage | Determine the biological matrix(es) associated with a quantifiable doxycycline dosage in more than 90% of the samples collected during the study. | Up to 90 days | 
| Cmax (maximum concentration) in plasma |  | Until day 90 | 
| Cmax (maximum concentration) in whole blood |  | Until day 90 | 
| Cmax (maximum concentration) in Dried Blood Spot (DBS) |  | Until day 90 | 
| Cmax (maximum concentration) in urine |  | Until day 90 | 
| Cmax (maximum concentration) in hair |  | Until day 90 | 
| AUC (area under the curve) in plasma |  | Until day 90 | 
| AUC (area under the curve) in whole blood |  | Until day 90 | 
| AUC (area under the curve) in Dried Blood Spot (DBS) |  | Until day 90 | 
| AUC (area under the curve) in urine |  | Until day 90 | 
| AUC (area under the curve) in hair |  | Until day 90 | 
| Elimination clearance in plasma |  | Until day 90 | 
| Elimination clearance in whole blood |  | Until day 90 | 
| Elimination clearance in Dried Blood Spot (DBS) |  | Until day 90 | 
| Elimination clearance in urine |  | Until day 90 | 
| Elimination clearance in hair |  | Until day 90 | 
| Half-life in plasma |  | Until day 90 | 
| Half-life in whole blood |  | Until day 90 | 
| Half-life in Dried Blood Spot (DBS) |  | Until day 90 | 
| Half-life in urine |  | Until day 90 | 
| Half-life in hair |  | Until day 90 | 
| Mean residence time in plasma |  | Until day 90 | 
| Mean residence time in whole blood |  | Until day 90 | 
| Mean residence time in Dried Blood Spot (DBS) |  | Until day 90 | 
| Mean residence time in urine |  | Until day 90 | 
| Mean residence time in hair |  | Until day 90 | 
| Volume of distribution in plasma |  | Until day 90 | 
| Volume of distribution in whole blood |  | Until day 90 | 
| Volume of distribution in Dried Blood Spot (DBS) |  | Until day 90 | 
| Volume of distribution in urine |  | Until day 90 | 
| Volume of distribution in hair |  | Until day 90 |