In a patient who uses cannabis and has had unprotected intercourse with multiple male and female partners, some of whom are injection drug users (IDU), which of the following is an indication for HIV pre‑exposure prophylaxis (PrEP): cannabis use, multiple partners, unprotected intercourse, or partners who are IDU?

PrEP Indication in This Clinical Scenario

The correct answer is (c) unprotected intercourse, which is the primary indication for HIV pre-exposure prophylaxis in this patient. However, it's critical to understand that this patient has multiple overlapping indications that collectively make them an excellent candidate for PrEP.

Why Unprotected Intercourse is the Primary Answer

Unprotected intercourse is the direct behavioral risk factor that creates HIV exposure and is explicitly listed as a core indication for PrEP. 1 The International Antiviral Society-USA guidelines specifically identify "those who do not use condoms" as a population for whom PrEP is recommended. 1

Understanding All Risk Factors Present

This patient actually presents with three distinct PrEP indications simultaneously:

1. Multiple Sexual Partners

• Having multiple partners is explicitly listed as an indication for PrEP 1
• The guidelines state that "individuals who have multiple partners" should be offered PrEP 1
• This alone would qualify the patient for PrEP discussion 1

2. Partners Who Inject Drugs (IDU)

• Having sexual partners who are injection drug users is a specific PrEP indication 1
• The guidelines explicitly mention "individuals who share injection drug needles, syringes, or other equipment" and their sexual partners as PrEP candidates 1
• Sexual partnerships with IDUs represent an understudied but significant network-level risk factor for heterosexual HIV transmission 2
• Research shows HIV prevalence is higher among those with IDU partners (9.6%) compared to those without (4.6%) 2

3. Unprotected Intercourse

• This is the most direct indication, as condomless sex creates the actual exposure risk 1
• Daily TDF/emtricitabine is recommended for persons at risk through sexual exposure 1

Cannabis Use is NOT an Indication

Cannabis use is completely irrelevant to PrEP indication. 3 There is no evidence linking cannabis use to HIV transmission risk or PrEP candidacy. Recent research even suggests cannabis may have immunomodulatory effects in people with HIV, but this does not relate to PrEP indication. 4, 5, 6

Clinical Approach to This Patient

PrEP should be discussed and offered immediately to this patient without requiring specific screening tools or risk criteria. 1 The 2024 International Antiviral Society-USA guidelines recommend that "PrEP should be discussed and offered to all sexually active persons, all persons requesting PrEP...without need to limit access to specific criteria for sexual or drug use behavior." 1

Recommended PrEP Regimen

• Daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) is the recommended regimen 1
• Initiate with a double dose (2 tablets) on day 1, followed by once-daily dosing 1
• Maximum protection achieved within 24 hours for rectal exposures in MSM, approximately 7 days for vaginal exposures 1

Critical Counseling Points

• PrEP does not prevent other sexually transmitted infections 1
• Condoms remain recommended for all genital penetrative sex acts 1
• Quarterly STI screening is essential 1
• HIV testing should be performed before initiation and every 3 months during use 1

Common Pitfall to Avoid

Do not dismiss this patient's risk because they use cannabis. Cannabis use has no bearing on HIV risk or PrEP eligibility. The actual risk factors—unprotected sex, multiple partners, and partners who inject drugs—are what matter clinically. 1