STI Prevention Guidelines

Introduction to STI Prevention

• The American Medical Association and the Centers for Disease Control and Prevention recommend preventative measures for high-risk populations, including cisgender men who have sex with men and transgender women, to prevent bacterial STIs and HIV exposure 1, 2
• The Centers for Disease Control and Prevention recommends daily oral TDF/FTC as the preferred oral PrEP regimen for all populations at risk of HIV exposure, with an evidence rating of A1a 1, 2

PrEP Regimens

• The American College of Physicians and the World Health Organization recommend discussing and offering PrEP to all sexually active persons, individuals who inject drugs or use substances, and populations with high HIV incidence rates, including long-acting cabotegravir as an injectable PrEP option 1
• The Centers for Disease Control and Prevention recommends starting PrEP within 72 hours of known HIV exposure, typically involving a 28-day course of antiretroviral medications 2

DoxyPEP Administration

• The American Medical Association and the Centers for Disease Control and Prevention recommend a dosing regimen of 200 mg DoxyPEP taken as a single dose within 72 hours after condomless sex, with a maximum of 200 mg per 24-hour period, and quarterly STI screening of contact sites and blood syphilis testing 1, 3
• The American College of Physicians recommends prescribing DoxyPEP with 30 doses (60 tablets/capsules) at a time 1

STI Screening and Vaccination

• The Centers for Disease Control and Prevention, the American College of Physicians, and the World Health Organization recommend hepatitis B vaccination at initial examination with follow-up doses at 1-2 and 4-6 months, as well as vaccination as the primary preventive measure for all unvaccinated patients being evaluated for an STD 4, 5
• The World Health Organization recommends vaccination for men who have sex with men and persons who use illegal drugs 4

Medication Management

• The American Medical Association, the Centers for Disease Control and Prevention, and the American College of Physicians recommend considering potential side effects of DoxyPEP, including photosensitivity, esophagitis, and gastrointestinal intolerance, and taking DoxyPEP with food and plenty of fluid, remaining upright for at least 1 hour after taking, and separating the dose from dairy products, antacids, and supplements containing calcium, iron, magnesium, or sodium bicarbonate by at least 2 hours 3

Monitoring and Follow-up

• The Centers for Disease Control and Prevention and the American College of Physicians recommend baseline testing, including HIV screening with RNA test and laboratory-based antigen-antibody test, regular HIV testing and STI screening every 3-6 months, and renal monitoring for TDF-based PrEP 1, 2, 5
• The American Medical Association recommends that TDF-based PrEP is not recommended in persons with creatinine clearance below 60 mL/min/1.73m² 2

Prevention Strategies

• The American College of Physicians, the Centers for Disease Control and Prevention, and the World Health Organization recommend condom use as a cornerstone of prevention for all penetrative sex acts, with an evidence rating of AIII, as well as regular STI screening at anatomic sites of exposure every 3-6 months, and risk reduction counseling to accompany all preventative medication strategies 1, 3
• The Centers for Disease Control and Prevention recommends prophylactic treatment for individuals who have experienced sexual assault, including a combination regimen of ceftriaxone, metronidazole, and azithromycin/doxycycline, and hepatitis B vaccination at the initial examination, with follow-up doses at 1-2 and 4-6 months 4

• The recommended regimen consists of:

  Medication	Dosage
  Ceftriaxone	125 mg IM in a single dose
  Metronidazole	2 g orally in a single dose
  Azithromycin	1 g orally in a single dose
  Doxycycline	100 mg orally twice a day for 7 days

  4

• Patients should be counseled about possible gastrointestinal side effects with the combination regimen, and follow-up examinations are recommended at 2 weeks after the assault, with serologic tests for syphilis and HIV repeated at 6, 12, and 24 weeks if initial results were negative 4, 6
• DoxyPEP reduces syphilis and chlamydia infections by >70% and gonococcal infections by approximately 50% in high-risk populations, and ongoing need for DoxyPEP should be reassessed every 3-6 months 3
• Baseline STI testing is recommended at initiation of DoxyPEP, and regular STI screening should be performed every 3-6 months at anatomic sites of exposure, including nucleic acid amplification test for gonorrhea and chlamydia, serologic testing for syphilis, and HIV testing for those not known to be HIV-positive 3
• Prophylactic medication should be implemented as part of a comprehensive sexual health approach, including risk reduction counseling, regular STI screening and treatment, recommended vaccinations (hepatitis B, HPV), and HIV PrEP or treatment as appropriate 4, 3