Doxy PEP For Preventing Sexually Transmitted Infections

While many people are familiar with PrEP for HIV prevention, not everyone is aware the antibotic doxycycline can be used to prevent STI’s. In particular, doxycycline can be useful in prevention of Syphilis, Chlamydia, and Gonorrhoea infections.

If you have had multiple STI’s, prevention with Doxy PEP after sex may be an option to reduce your risk of sexual infections.

What is the level of protection?

Doxy PEP is a good way to reduce the chance of STI’s however the degree of reduction is different for each disease.

Infection	Reduction If HIV negative	Reduction if HIV positive
Chlamydia	88%	74%
Syphilis	87%	77%
Gonorrhoea	55%	57%

Reduction in STIs when taking doxycycline within 72h post sex. ¹

Efficacy against other bacterial STIs is not known, and doxy-PEP does not prevent HIV, monkeypox (MPX) or other viral infections, for example HPV and HSV. ²

How do I take doxy PEP?

To take doxy PEP you simply need to take 200mg of Doxycycline within 72h after sex. The earlier you take it the better however the effect is still present up to 3 days after sex.

If you have had sex multiple times in a day you only need to take the dose once. There is no need for more than 200mg of doxycycline in a day.

Australian Guidelines Update:

Concerned about potential for antibiotic resistance, The Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM), have recommended the following:

If a Doxy-PEP user tends to have multiple sexual partners during weekends but few during the week, then a single Monday morning dose of 200mg Doxy-PEP should adequately cover their STI risk, rather than multiple doses over the weekend.

Gonorrhoea is already showing early antibiotic resistance. For this reason your doctor is recommended to check for resistance if there is a suspected or confirmed gonococcal gonorrhoea infection. ³

This is done with a simple swab before treatment.

Side Effects

Doxycycline can be hard on the stomach occasionally causing nausea. It’s recommended to take it with some food to help line the stomach.

Doxycycline also can have a risk of red inflammed skin if you are exposed to sunlight. It’s recommended to avoid getting sunburned when taking doxy PrEP.

Is Doxy PEP For Me?

If you have had multiple STI’s and feel you would like to reduce your chance of infection, talk wtih your doctor.

Of course while the chance of infection is reduced, the risk is not eliminated. Be sure to schedule a regular full sexual health screening. Your regular HIV PrEP appointment is a great chance to organise this testing.

If you are in Melbourne or Sydney, Dr George Forgan-Smith is happy to discuss you options to protect your sexual Health including Doxy PEP.
Dr George works at:

Collins Street Medical Centre, L7 267 Collins Street Melbourne VIC. Ph: (03) 8575 6900
Holdsworth House, L3 26 College St, Darlinghurst NSW. Ph: (02) 9331 7228