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Tetracycline Antibiotic

Doxycycline for Sexually Transmitted Infections

Phase 4
Recruiting
Led By Troy Grennan, MD
Research Sponsored by Jonathan Troy Grennan
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Any sexual activity (i.e. oral sex, insertive or receptive anal sex, with or without a condom) with more than one male partner in the preceding 12 months
Males, ≥ 18 years of age
Timeline
Screening 3 weeks
Treatment Varies
Follow Up 60 weeks
Awards & highlights

Study Summary

This trial will investigate the efficacy of STI PrEP and STI PEP to reduce bacterial STIs in gbMSM, and address the rising epidemic of bacterial STIs in Canada.

Who is the study for?
The DISCO trial is for gay, bisexual, and other men who have sex with men (gbMSM) over 18 years old. Participants must have had multiple male partners and at least one bacterial STI in the past year. They should not be on certain drugs that affect doxycycline levels, allergic to tetracyclines, using doxycycline regularly or taking isotretinoin.Check my eligibility
What is being tested?
This study tests whether Doxycycline Hyclate can prevent bacterial STIs like syphilis, chlamydia, and gonorrhea in gbMSM. It's a randomized controlled trial comparing two prevention strategies: pre-exposure prophylaxis (PrEP) versus post-exposure prophylaxis (PEP).See study design
What are the potential side effects?
Doxycycline may cause side effects such as stomach upset, sun sensitivity leading to severe sunburns, changes in color of teeth if used long term during tooth development stages before age eight or during pregnancy.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
Select...
I have had sexual activity with more than one male partner in the last year.
Select...
I am a man aged 18 or older.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~60 weeks
This trial's timeline: 3 weeks for screening, Varies for treatment, and 60 weeks for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Plasma doxycycyline levels to determine efficacy of doxycycline chemoprophylaxis
Secondary outcome measures
Change in self-reported sexual activity defined as increases in condomless sexual acts and number of sexual partners based on responses from questionnaires
Frequency of STIs over time
Proportion of cases with resistance to penicillins, tetracyclines or macrolides in syphilis, and tetracycline resistance in gonorrhea and chlamydia isolates taken from the anus, oral cavity or urethra.
+5 more

Side effects data

From 2021 Phase 4 trial • 22 Patients • NCT05399290
9%
Photoallergic reaction
100%
80%
60%
40%
20%
0%
Study treatment Arm
100 mg Standard Dose Doxycycline BID
20 mg Sub-antimicrobial Dose Doxycycline BID

Trial Design

2Treatment groups
Experimental Treatment
Group I: STI PrEP armExperimental Treatment1 Intervention
doxycycline capsules 100mg orally daily for 12 months. Though the usual treatment dose of doxycycline is 100mg twice daily
Group II: STI PEP armExperimental Treatment1 Intervention
doxycycline 200mg orally once within 24-72 hours following each sexual encounter deemed at risk (i.e. condomless anal or oral sex), to a maximum of six pills (i.e. 600 mg total) per week
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
Doxycycline
FDA approved

Find a Location

Who is running the clinical trial?

Canadian Institutes of Health Research (CIHR)OTHER_GOV
1,345 Previous Clinical Trials
26,452,954 Total Patients Enrolled
Jonathan Troy GrennanLead Sponsor
Troy Grennan, MDPrincipal InvestigatorUniversity of British Columbia
2 Previous Clinical Trials
104 Total Patients Enrolled

Media Library

Doxycycline Hyclate (Tetracycline Antibiotic) Clinical Trial Eligibility Overview. Trial Name: NCT04762134 — Phase 4
Sexually Transmitted Bacterial Diseases Research Study Groups: STI PrEP arm, STI PEP arm
Sexually Transmitted Bacterial Diseases Clinical Trial 2023: Doxycycline Hyclate Highlights & Side Effects. Trial Name: NCT04762134 — Phase 4
Doxycycline Hyclate (Tetracycline Antibiotic) 2023 Treatment Timeline for Medical Study. Trial Name: NCT04762134 — Phase 4

Frequently Asked Questions

These questions and answers are submitted by anonymous patients, and have not been verified by our internal team.

Is there a minimal risk associated with utilizing the sexually transmitted infection post-exposure prophylaxis protocol?

"Due to the Phase 4 status of this prophylactic treatment, our team at Power rated its safety as a 3 on their scale."

Answered by AI

How many people are included in this clinical experiment?

"Affirmative. Clinicaltrials.gov shows that this clinical trial was publicly announced on June 2nd, 2023 and is currently looking for 560 participants from 1 separate medical facility."

Answered by AI

Are there presently any vacancies for participants in this research project?

"According to clinicatrials.gov, recruitment is currently underway for this study which was originally listed on June 2nd 2023 and had its most recent update posted a few weeks later on the 26th of June."

Answered by AI

In what situations is STD post-exposure prophylaxis typically prescribed?

"Severe acne can be managed with STI PEP arm. Additionally, this medication has been found to address other medical issues such as trachoma, disease and klebsiella infections."

Answered by AI

Who else is applying?

What site did they apply to?
BC Centre for Disease Control
What portion of applicants met pre-screening criteria?
Did not meet criteria
Recent research and studies
clinicaltrials.govStudy
Doxycycline Intervention for Bacterial STI ChemoprOphylaxis (DISCO)
Jonathan Troy Grennan 2023. "Doxycycline Intervention for Bacterial STI ChemoprOphylaxis (DISCO)". ClinicalTrials.gov. https://clinicaltrials.gov/ct2/show/NCT04762134.
~373 spots leftby Dec 2026
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