US CDC issue preliminary guidance for use of PrEP
Simon Collins, HIV i-Base
On 27 January 2011 the US Centre for Disease Control (CDC) issued preliminary guidance for the use of tenofovir/FTC (Truvada) as primary prophylaxis against HIV infection for gay men at high risk of exposure. 
This was based on results from the iPrEX study  and is notable as Truvada is not licensed as a prevention medication. The preliminary guidelines were issued in the hope they will reduce potentially less effective PrEP-related practices by health providers and in the community. Completing the full guidelines and obtaining expert input and public comment is expected to take several months.
The guidelines emphasise PrEP use only in a similar setting to the iPrEX study ie only in men who have sex with men and only if they are at high risk. Additionally this should be part of broad health protection care, with limited prescriptions and regular HIV testing.
The guidance in Table 1 is an outline for healthcare providers who decide to prescribe Truvada for PrEP prior to licensing.
Table 1. CDC interim guidance for health-care providers electing to provide preexposure prophylaxis (PrEP) for the prevention of HIV infection in adult men who have sex with men and who are at high risk for sexual acquisition of HIV
Before initiating PrEP
- Document negative HIV antibody test(s) immediately before starting PrEP medication.
- Test for acute HIV infection if patient has symptoms consistent with acute HIV infection.
- Confirm that patient is at substantial, ongoing, high risk for acquiring HIV infection.
- Confirm that calculated creatinine clearance is =60 mL per minute (via Cockcroft-Gault formula).
Other recommended action:
- Screen for hepatitis B infection; vaccinate against hepatitis B if susceptible, or treat if active infection exists, regardless of decision about prescribing PrEP.
- Screen and treat as needed for STIs.
Beginning PrEP medication regimen
- Prescribe 1 tablet of Truvada (tenofovir 300 mg plus FTC 200 mg) daily.
- In general, prescribe no more than a 90-day supply, renewable only after HIV testing confirms that patient remains HIV-uninfected.
- If active hepatitis B infection is diagnosed, consider using TDF/FTC for both treatment of active hepatitis B infection and HIV prevention.
- Provide risk-reduction and PrEP medication adherence counseling and condoms.
Follow-up while PrEP medication is being taken
- Every 23 months, perform an HIV antibody test; document negative result.
- Evaluate and support PrEP medication adherence at each follow-up visit, more often if inconsistent adherence is identified.
- Assess STI symptoms and, if present, test and treat for STI as needed.
- Every 6 months, test for STI even if patient is asymptomatic, and treat as needed.
- 3 months after initiation, then yearly while on PrEP medication, check blood urea nitrogen and serum creatinine.
On discontinuing PrEP (at patient request, for safety concerns, or if HIV infection is acquired)
- Perform HIV test(s) to confirm whether HIV infection has occurred.
- If HIV positive, order and document results of resistance testing and establish linkage to HIV care.
- If HIV negative, establish linkage to risk-reduction support services as indicated.
- If active hepatitis B is diagnosed at initiation of PrEP, consider appropriate medication for continued treatment of hepatitis B.
HIV = human immunodeficiency virus
STI = sexually transmitted infection
TDF = tenofovir disoproxil fumarate
FTC = emtricitabine.
- Interim Guidance: Preexposure Prophylaxis for the Prevention of HIV Infection in Men Who Have Sex with Men. Morbidity and Mortality Weekly Report (MMWR) January 28, 2011 / 60(03);65-68.
- The iPrEX study was reported in HTB November/December 2010