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Tetracycline Antibiotic

Doxycycline for Sexually Transmitted Infections

N/A

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

Must not have

Any individual capable of becoming pregnant.

Individuals currently using isotretinoin

Timeline

Screening 3 weeks

Treatment Varies

Follow Up 60 weeks

Awards & highlights

All Individual Drugs Already Approved

Approved for 60 Other Conditions

No Placebo-Only Group

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.

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).

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

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I have had sexual activity with more than one male partner in the last year.

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I am a man aged 18 or older.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:

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I am capable of becoming pregnant.

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I am currently taking isotretinoin.

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I am currently taking tetracycline or doxycycline regularly.

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I am not taking medications like barbiturates, phenytoin, or carbamazepine.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ 60 weeks

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

Study objectives can provide a clearer picture of what you can expect from a treatment.

Primary study objectives

Plasma doxycycyline levels to determine efficacy of doxycycline chemoprophylaxis

Secondary study objectives

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

Photoallergic reaction

100%

80%

60%

40%

20%

Study treatment Arm

100 mg Standard Dose Doxycycline BID

20 mg Sub-antimicrobial Dose Doxycycline BID

Awards & Highlights

All Individual Drugs Already Approved

Therapies where all constituent drugs have already been approved are likely to have better-understood side effect profiles.

Approved for 60 Other Conditions

This treatment demonstrated efficacy for 60 other conditions.

No Placebo-Only Group

All patients enrolled in this study will receive some form of active treatment.

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

0 / 6Eligibility criteria met