Doxy-PEP (Bacterial STI Prevention)#

You may be eligible for Doxy-PEP if any of the following apply:

• You're a biological male sexually active with men (MSM). This is the population where the evidence is strongest.
• You're a transgender woman who is sexually active.
• You've had a bacterial STI in the past 12 months (chlamydia, gonorrhea, trichomoniasis, or syphilis) - regardless of your gender or partner type.
• You've had multiple sexual partners in the past 12 months - regardless of your gender or partner type.

This means cisgender women, transgender men, non-binary patients, men who have sex with women, women who have sex with women, and others can be eligible through the third or fourth criteria - the eligibility framework recognises that bacterial STI risk isn't limited to any single gender or partner pattern.

The clinician reviews your intake and confirms whether Doxy-PEP is appropriate for your specific situation.

Several published trials - including the DoxyPEP trial (NEJM, 2023), the ANRS DoxyVAC study, and the IPERGAY substudy - have looked at Doxy-PEP's effect on bacterial-STI incidence in specific patient populations. The published findings generally describe:

• Reductions in chlamydia and syphilis incidence in studied populations.
• More variable findings for gonorrhea, with the variation linked to local tetracycline-resistance patterns.

Specific numbers and details vary by trial and population. Your clinician can discuss what the evidence base suggests for your particular situation.

Doxy-PEP does not act against:

• HIV - see PrEP for HIV prevention.
• Viral STIs like herpes (HSV), HPV, or hepatitis B/C.
• Mycoplasma genitalium (Mgen) or trichomoniasis - those are different organisms.

Like any prescription antibiotic regimen, Doxy-PEP has trade-offs that the clinician will weigh with you:

• Reported side effects in studies and clinical practice include mild gastrointestinal symptoms (nausea, occasional stomach discomfort), increased sun sensitivity, and occasional candidiasis (yeast overgrowth) from antibiotic-related microbiome changes.
• Esophageal irritation can occur with this medication class if the pill sits in the esophagus. The "how to take" section below covers how to reduce that risk.
• Antimicrobial resistance is an ongoing area of study:
  • Some research has reported increased tetracycline-resistant Staph aureus carriage among regular users.
  • There is a theoretical concern about tetracycline-resistant Neisseria gonorrhoeae in the community - gonorrhea resistance is already a public-health concern in some regions.
  • Repeated antibiotic use causes microbiome changes that researchers are still characterising.

Public-health bodies continue to monitor these trade-offs. Your clinician will discuss whether the balance is reasonable for your specific situation.

Doxy-PEP is not appropriate if you have any of these:

• Active STI symptoms. Doxy-PEP is a single-dose preventive regimen - it is not sufficient to treat an established infection. If you have symptoms suggestive of chlamydia, gonorrhea, or another STI (discharge, painful urination, genital sores, pelvic/testicular pain, etc.), submit a standard STI Testing and Treatment consultation instead so the clinician can arrange testing and the appropriate treatment regimen.
• Tetracycline-class allergy - an absolute contraindication.
• Pregnancy - tetracyclines can affect fetal tooth and bone development.
• Breastfeeding - not recommended.
• Under age 18 - tetracycline-class antibiotics can affect tooth development in younger patients.
• Severe active liver disease - the clinician will review on a case-by-case basis; caution is warranted.

If you're already taking a daily tetracycline-class antibiotic (for acne, for example), your body already has drug levels in the same range studied for Doxy-PEP - additional event-driven doses aren't needed. Mention this in your intake.

Take a single oral dose within 24 hours of a sexual exposure (ideally within 72 hours at the outside).

• The dose is taken as a single one-time dose per exposure - not daily, not a multi-day course.
• If you have multiple exposures in a short window, your clinician can advise on safe dosing frequency (most guidelines suggest a weekly maximum to limit antibiotic exposure).

A few practical points to get the most out of each dose and avoid side effects:

• Take with a full glass of water.
• Stay upright for at least 30-60 minutes after the dose (don't take it right before bed). The medication can cause esophageal irritation if it sits in the esophagus.
• Avoid dairy, calcium supplements, iron, magnesium, or antacids within 2 hours of the dose - these bind the medication and reduce its absorption, which makes the dose less effective.
• You can take it with a small amount of plain food if it upsets your stomach on an empty stomach.

Each dose is timed to the specific sexual encounter that preceded it. The regimen is event-driven - it does not provide ongoing coverage for future exposures. You take a dose after each potential exposure.

Yes. The major Doxy-PEP trials included both rectal and oral mucosal exposures in their study populations, and the published findings cover those exposure sites.

No problem. Doxy-PEP is taken only when you have an exposure. If a month passes and you've had no exposures, you've taken no doses - that's fine, the prescription just stays on hand for if you need it. No "wasted" medication, no tapering needed if you decide to stop carrying it.

• Antacids, calcium supplements, iron, magnesium, dairy - all reduce absorption. Separate by at least 2 hours from your Doxy-PEP dose.
• Acne medications in the oral retinoid class - taking with tetracycline-class antibiotics has been associated with increased intracranial pressure. Mention if you're on retinoid acne treatment.
• Hormonal contraception - older concern, but published evidence is reassuring. Not a clinically significant interaction.
• HIV treatment medications - less of an issue for occasional Doxy-PEP than for chronic tetracycline-class antibiotic use, but worth a clinician review if you're on HIV treatment.
• Older vitamin-K-antagonist blood thinners - tetracycline-class antibiotics can increase this blood-thinner's effect. Mention any blood thinner you take in your intake.

Tell the clinician about all prescription medications, over-the-counter medications, and supplements in your intake so any interactions can be flagged.

1. Choose the Doxy-PEP panel on teletest.ca.
2. Complete the health-history intake. Mention your typical exposure patterns, past STI history, current medications, and any allergies.
3. You can also request STI screening at the same time. If you'd like a lab requisition for chlamydia, gonorrhea, trichomoniasis, HIV, and syphilis arranged alongside the Doxy-PEP prescription, mention this in the intake. The clinician can issue both the prescription and the lab requisition from the same consultation - one consultation fee, two outputs.
4. A clinician reviews your intake and confirms whether Doxy-PEP is appropriate. Most patients receive a response by secure message - almost always within a few hours.
5. If approved, the prescription is faxed directly to the pharmacy of your choice in Ontario or BC. The lab requisition (if requested) is faxed to your chosen lab.

A typical TeleTest Doxy-PEP prescription includes 3 doses:

• 1 dose for immediate use after your most recent exposure (if applicable).
• 2 doses to keep on hand for future exposures.

When you've used your supply, submit a new Doxy-PEP consultation through your portal to refill. The clinician will review your usage pattern and frequency before issuing the next prescription.

If you find yourself running out faster than expected, message us through the portal and the clinician can discuss the appropriate maximum frequency for your situation.

Doxy-PEP doesn't replace routine STI testing. While on Doxy-PEP, regular STI screening every 3 months is recommended to:

• Catch any infections that Doxy-PEP didn't prevent.
• Monitor specifically for syphilis (which can sometimes still occur despite Doxy-PEP).
• Pick up Mgen, trichomoniasis, or HIV - none of which Doxy-PEP prevents.

You can do this through TeleTest's STI Testing and Treatment panel or, if you test frequently, the STI Testing Subscription (best fit for patients screening every 2-3 weeks).

• The TeleTest consultation fee is not covered by provincial health plans.
• The medication itself is generally inexpensive out of pocket - tetracycline-class antibiotics are among the least costly prescription antibiotics. The main out-of-pocket cost is usually the pharmacy dispensing fee, which is often only a few dollars for a typical prescription quantity (and varies by pharmacy - independents and Costco tend to be lower than the big chains).
• Many private drug plans cover the medication.
• Provincial drug plans may cover the medication depending on your situation.

Check with your pharmacy or drug plan for current pricing. For pharmacy-shopping tips, see Prescriptions.

PrEP and Doxy-PEP can be used together - they target different infections and don't interact.

Yes. Doxy-PEP and PrEP are different drug classes used in different ways. Studies and clinical practice describe them as not interfering with each other, and they are commonly used together by patients with both bacterial-STI and HIV risk.

Canadian sexual-health guidelines describe a layered approach for patients with elevated bacterial-STI and HIV risk. The components typically discussed include:

• PrEP - for HIV prevention.
• Doxy-PEP - for bacterial-STI prevention.
• Condoms - for additional bacterial-STI protection and for infections neither PrEP nor Doxy-PEP covers (herpes, HPV).
• Regular STI testing (every 3 months or more frequently) to identify any infections that aren't prevented.
• Hepatitis A and B vaccination if not already immune.

Each component has its own evidence base. Your clinician can discuss which combination is appropriate for your situation.

Most guideline recommendations suggest a maximum weekly frequency to limit antibiotic exposure and reduce the resistance impact. The exact limit is evolving and depends on guideline updates - your clinician will discuss the appropriate ceiling for your situation during the consultation.

No prevention strategy is 100% effective. If a routine STI test comes back positive while you're using Doxy-PEP:

• A follow-up link will appear in your TeleTest portal.
• TeleTest can issue oral antibiotic treatment for chlamydia, gonorrhea, or trichomoniasis. TeleTest does not treat syphilis (treatment requires an injection that must be given in person); for a positive syphilis result, you will need in-person care through your family doctor, a sexual-health clinic, or a public-health unit.
• Continue Doxy-PEP after future exposures unless your clinician advises otherwise.

A positive test doesn't mean Doxy-PEP failed - it means it didn't prevent that specific exposure, which can happen with any prevention strategy. Gonorrhea in particular is more likely to break through because of variable tetracycline-resistance patterns.

No. If you're already taking a daily tetracycline-class antibiotic (commonly prescribed for acne, for example), your body already has drug levels in the same range studied for Doxy-PEP. Additional event-driven doses aren't needed. Mention your current prescription in your intake.

When you eventually stop the daily antibiotic, that's a good time to discuss whether event-driven Doxy-PEP would be appropriate as a follow-on.

No tapering or special stopping plan needed. Doxy-PEP is event-driven, not continuous - if you decide you no longer want to take doses, you simply stop. There's no withdrawal or rebound effect.

The medication class makes skin more prone to sunburn even in modest sun exposure:

• Use sunscreen (SPF 30+) on exposed skin, especially face, neck, ears, and hands.
• Wear a hat in summer or when spending extended time outdoors.
• Be aware that even short outdoor activity can lead to sunburn if you're not used to the medication - this can apply for the first 24-48 hours after a dose and sometimes longer with repeated dosing.
• Reapply sunscreen if you're sweating or swimming.