Efficacy of Doxycycline as PEP to Prevent Bacterial STIs
Efficacy of doxycycline as PEP to prevent bacterial STIs search strategy:
MEDLINE/PubMed and Embase were searched through June 30, 2023 using the terms: Medline/PubMed: (doxycycline) AND (chlamydia OR gonorrhea OR syphilis) AND (PEP OR post-exposure prophylaxis OR pre-exposure prophylaxis OR PrEP) AND (Clinical Trial[pt]).
EMBASE: (‘doxycycline’/exp OR doxycycline) AND (‘chlamydia’/exp OR chlamydia OR ‘gonorrhea’/exp OR gonorrhea OR ‘syphilis’/exp OR syphilis) AND (pep OR ‘post-exposure prophylaxis’/ex OR ‘post-exposure prophylaxis’ OR ‘pre-exposure prophylaxis’/exp OR ‘pre-exposure prophylaxis’ OR prep) AND randomized. Abstracts presented at major scientific conferences were also reviewed.
Inclusion criteria: randomized controlled trial; English; evaluated PEP as STI bacterial prophylaxis
Exclusion criteria: non-human subjects or in-vitro studies; unrelated papers; duplicates; unavailable full texts; abstract-only papers; case reports; non-English
| Design | Participants | Intervention | Primary Endpoint | Findings | Limitations | Quality of Evidence | |
|---|---|---|---|---|---|---|---|
| iPrEx Trial
France 2018(1) |
RCT | N=232 MSM and TGW on TDF/FTC as PrEP (HIV-) | Doxycycline hyclate 200mg orally once within 24-72 hours after having condomless anal or oral sex versus no prophylaxis | First STI infection (gonorrhea, chlamydia or syphilis) during a 10-month follow-up period | Reduced risk of acquiring chlamydia and syphilis by 70% (HR 0.30 (95% CI 0.13-0.70) and 73% (HR 0.27 (95% CI 0.07-0.98), respectively.
No significant difference in gonorrhea |
Open-label
Short follow-up |
High |
| DoxyPeP
USA 2023(2) |
RCT | N=554 MSM and TGW (N=360 on PrEP; N=194 HIV+) | Doxycycline hyclate 200mg orally once within 72 hours after having condomless sex versus no prophylaxis | Relative risk of an STI infection per quarter. | PrEP: 65 STI endpoints (29.5%) occurred in controls and 47 (9.6%) in doxyPEP participants (RR 0.33; 95%CI 0.23-0.47; p<0.0001).
HIV: 30 STI endpoints (27.8%) in controls and 31 (11.7%) in doxyPEP participants (RR 0.42; 95% CI 0.25-0.75; p=0.0014). |
Open-label
Short follow-up |
High |
| DOXYVAC
France CROI 2023(3) |
RCT | N=502 MSM on HIV PrEP (HIV-) | Doxycycline monohydrate 200mg orally within 24-72 hours after sex versus no PEP versus 4CMenB vaccine versus no vaccine | Impact of doxycycline as PEP on time to first episode of syphilis or chlamydia and impact of 4CMenB vaccine on first episode of gonorrhea | Doxycycline as PEP reduced gonorrhea, chlamydia and syphilis infections (aHR of 0.49 (95% CI 0.32-0.76), 0.11 (95% CI 0.04-0.30) and 0.21 (95% CI 0.09-0.47), respectively). Receipt of 4CMenB was associated with a reduction in gonococcal infection (incidence 9.8/100 person years vs 19.7/100 person years in the study arm that did not receive vaccine; aHR 0.49 (95% CI 0.27-0.88) | Open-label
Short follow-up |
High |
| dPEP
Kenya CROI 2023 (4) |
RCT | N= 449 Cisgender women | Doxycycline hyclate 200mg orally within 72 hours after sex versus no doxycycline PEP | Any incident C. trachomatis, N. gonorrhoeae or T. pallidum | All bacterial STIs (RR 0.88; 95%CI 0.60-1.29), C. trachomatis (RR 0.73; 95% CI 0.47-1.13); N. gonorrhoeae (RR 1.64; 95% CI 0.78-3.47). There were only two syphilis infections during the study. | Open label, short follow-up | High |
RCT = randomized controlled trial
MSM = Men who have sex with men
TGW = Transgender women
References
- Molina JM, Charreau I, Chidiac C, et al. Post-exposure prophylaxis with doxycycline to prevent sexually transmitted infections in men who have sex with men: an open-label randomised substudy of the ANRS IPERGAY trial. Lancet Infect Dis. 2018 Mar;18(3):308-317.
- Luetkemeyer AF, Donnell D, Dombrowski JC, et al. Postexposure doxycycline to prevent bacterial sexually transmitted infections. N Engl J Med. 2023 Apr 6;388(14):1296-1306. DoxyPEP Reference (Conference Data- needs to be updated when paper available)
- Jean-Michel Molina, Beatrice Bercot, Lambert Assoumou, Algarte-Genin Michele, Emma Rubenstein, Gilles Pialoux, et al. ANRS 174 DOXYVAC: An Open-Label Randomized Trial to Prevent STIs in MSM on PrEP. CROI [Internet]. 2023 Feb 19;Seattle, Washington. Available from: https://www.croiconference.org/abstract/anrs-174-doxyvac-an-open-label-randomized-trial-to-prevent-stis-in-msm-on-prep/
- Stewart J, Oware K, Donnell D, Violette L, Odoyo J, Simoni J, et al. Self-reported adherence to event-driven doxycycline postexposure prophylaxis for sexually transmitted infection prevention among cisgender women. STI and HIV 2023 World Congress, Chicago, IL. 2023 Jul 24; Seattle, Washington. Available from: https://www.croiconference.org/abstract/doxycycline-postexposure-prophylaxis-for-prevention-of-stis-among-cisgender-women/.