Is PrEP with Truvada (emtricitabine/tenofovir disoproxil fumarate) or Descovy (emtricitabine/tenofovir alafenamide) indicated for a patient at risk of HIV?

Medical Necessity Determination for HIV Pre-Exposure Prophylaxis (PrEP)

Yes, PrEP with either Truvada (emtricitabine/tenofovir disoproxil fumarate) or Descovy (emtricitabine/tenofovir alafenamide) is medically indicated for this patient if they are confirmed HIV-negative and meet criteria for being at risk of HIV acquisition. 1, 2

Mandatory Pre-Authorization Requirements

Before approving this medication, the following must be documented:

• Negative HIV test immediately prior to PrEP initiation using combined HIV antibody and antigen testing 1, 2

  • If acute HIV infection is suspected (flu-like symptoms, recent high-risk exposure), HIV RNA testing must also be negative 1, 2
  • PrEP is absolutely contraindicated if HIV status is positive or unknown 2

• Creatinine clearance ≥60 mL/min (calculated by Cockcroft-Gault formula) for Truvada 1, 3

  • For Descovy, can be used with creatinine clearance 30-60 mL/min in men who have sex with men (MSM) only 3

• Hepatitis B surface antigen testing completed 1

Risk Stratification for Medical Necessity

PrEP is medically necessary if the patient meets any of these criteria:

• HIV-seronegative partner of an HIV-infected person who is not consistently virally suppressed 1, 4
• Member of a population with HIV incidence ≥2% per year 1
• Men who have sex with men with recent bacterial sexually transmitted infections or high-risk sexual behavior 1, 3
• Heterosexually active adults in HIV-discordant relationships 1
• Persons who inject drugs and share injection equipment 5

Medication Selection Algorithm

For cisgender women or transgender men at risk through vaginal exposure:

• Truvada (TDF/FTC) is the ONLY approved and effective option 4, 3
• Descovy is NOT recommended for cisgender women—it lacks proven efficacy data in this population 3, 6
• Daily dosing is critical as tenofovir concentrates 10-fold lower in vaginal tissue than rectal tissue 4

For men who have sex with men (MSM) or transgender women:

• First-line: Truvada (TDF/FTC) 300/200 mg daily 1, 3, 5
• Alternative: Descovy (TAF/FTC) 25/200 mg daily if the patient has: 3, 7, 6
  • Creatinine clearance 30-60 mL/min, OR
  • Osteopenia or osteoporosis, OR
  • Age >50 years with renal risk factors
• Descovy showed non-inferior efficacy to Truvada with superior bone and renal safety profiles in the DISCOVER trial 7

For heterosexually active men:

• Truvada is recommended 1

Ongoing Monitoring Requirements for Continued Authorization

The following monitoring schedule must be documented for continued medical necessity:

Every 3 months: 1, 3

• Combined HIV antibody and antigen testing
• Three-site STI screening (rectal, pharyngeal, urogenital for MSM; genital for others) for gonorrhea and chlamydia by NAAT
• Syphilis testing
• Pregnancy testing for individuals of childbearing potential
• Assessment of adherence and risk behaviors

Every 6-12 months: 1, 3

• Serum creatinine and estimated glomerular filtration rate
• More frequent renal monitoring (every 3-6 months) required for patients >50 years, taking hypertension/diabetes medications, or baseline eGFR <90 mL/min

PrEP prescriptions should not exceed 90 days without interval HIV testing 1, 4

Critical Contraindications That Would Deny Authorization

• Positive or unknown HIV status 2
• Creatinine clearance <60 mL/min for Truvada 1, 3
• Creatinine clearance <30 mL/min for Descovy 3
• Request for Descovy in cisgender women (not FDA-approved for this population) 3, 6
• Active untreated hepatitis B requiring discontinuation (use caution—may cause hepatic flares) 1, 2

Common Pitfalls to Avoid

• Do not approve PrEP without documented negative HIV test within days of initiation—resistance can develop if inadvertently prescribed during acute HIV infection 5, 8
• Do not approve event-driven "2-1-1" dosing for anyone except MSM—inadequate tissue levels in vaginal tissue 1, 4
• Do not approve Descovy for cisgender women—no efficacy data exists 3
• Ensure 1-week lead-in period is explained for MSM before adequate rectal tissue levels are achieved 3

Expected Outcomes

When adherence is ≥70%, PrEP reduces HIV acquisition risk by 73% (RR 0.27) 8. With optimal daily adherence, efficacy exceeds 90% 5, 8. Discontinuation due to adverse events occurs in only 1-2% of patients 7, 8.