What Is HIV PrEP and How Does It Function?

For individuals at elevated HIV risk without a current diagnosis, pre-exposure prophylaxis (PrEP) may be an appropriate option. Daily adherence to this medication regimen substantially reduces HIV acquisition probability.

Pre-exposure prophylaxis (PrEP) represents a daily pharmaceutical intervention designed to prevent HIV infection onset. This preventive strategy specifically targets HIV-negative individuals facing increased viral exposure risk.

By mitigating HIV transmission potential, PrEP serves as protective measure for both users and their partners. This intervention is contraindicated for individuals with existing HIV diagnoses.

Currently, the FDA has approved two distinct antiviral formulations for PrEP application. Consistent administration demonstrates significant efficacy in HIV prevention.

Continue reading for comprehensive information regarding PrEP medications and their role in HIV risk reduction.

Section Navigation

PrEP Overview | Medication Types | Eligibility Criteria | Clinical Efficacy | Safety Profile | Key Takeaways

Mechanism of HIV Prevention Through PrEP

Pre-Exposure Prophylaxis (PrEP) employs nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), a class of antiviral agents that inhibit HIV viral replication processes.

Mandatory HIV testing precedes PrEP initiation and continues at minimum quarterly intervals throughout treatment to confirm negative serostatus.

Following potential HIV exposure or acute infection symptoms, PrEP administration must pause until negative test confirmation due to:

- PrEP's inability to independently treat established HIV infection
- Potential for developing antiviral resistance during active infection

PrEP protocols incorporate comprehensive prevention counseling addressing:

- Individualized HIV risk assessment
- Available prevention modalities
- Daily PrEP integration benefits

Treatment duration varies by individual health factors, requiring professional consultation for optimal regimen planning.

FDA-Approved PrEP Formulations

Current FDA-approved PrEP medications include Truvada and Descovy.

Truvada combines emtricitabine and tenofovir disoproxil fumarate, available in brand and generic versions across multiple strengths for HIV treatment and prevention. This once-daily tablet is approved for adults and adolescents (≥35kg/77lbs) of all genders.

Descovy contains emtricitabine and tenofovir alafenamide in daily tablet form for individuals ≥35kg. Current approval excludes females at risk through vaginal intercourse due to insufficient efficacy data in this population.

PrEP Candidate Profile

CDC data indicates approximately 1.2 million U.S. HIV diagnoses in 2018, with 14% unaware of their status. PrEP candidates include individuals with recent (past 6 months):

- Anal/vaginal intercourse with HIV-positive partner (detectable/unknown viral load)
- Inconsistent condom usage
- STI diagnosis

Additional candidates include injection drug users who:

- Share injection equipment
- Have HIV-positive injection partners

Frequent PEP users with persistent risk factors should consult healthcare providers regarding PrEP initiation.

PrEP Therapy Considerations

Advantages

- High efficacy with consistent use
- Dual protection for user/partners
- Convenient daily dosing
- Discreet prevention control
- Option for serodiscordant conception

Limitations

- Potential high cost (uninsured)
- Strict adherence requirements
- Quarterly HIV testing
- Possible adverse effects
- Contraindicated with severe renal impairment/hepatitis B history

PrEP Efficacy Data

CDC reports demonstrate PrEP’s 99% efficacy in preventing sexual HIV transmission and 74% efficacy among injection drug users with perfect adherence.

Optimal protection timelines:

- Receptive anal intercourse: 7 days
- Injection drug use/receptive vaginal intercourse: 21 days

Note: Descovy’s efficacy in receptive vaginal intercourse remains unestablished.

PrEP Safety Considerations

While generally safe, Truvada and Descovy may produce adverse effects. Contraindications include severe renal impairment and hepatitis B history (requires monitoring). PrEP is inappropriate for HIV-positive individuals due to resistance risks.

Common Effects

- Gastrointestinal disturbances
- Fatigue
- Cephalalgia

Serious Reactions

- Hypersensitivity manifestations
- Hepatic/renal complications
- Hepatitis B exacerbation
- Metabolic acidosis

Consult healthcare providers for complete safety information and potential drug interactions. Seek emergency care for severe reactions.

Initiating HIV Prevention Dialogue

- Review CDC educational materials
- Prepare discussion questions
- Disclose health concerns openly
- Inquire about testing/PEP access
- Explore uninsured options
- Develop partner communication strategies

Essential Conclusions

Individuals at potential HIV risk should prioritize regular testing and preventive counseling. PrEP integration offers substantial transmission risk reduction when properly implemented.

For personalized HIV prevention planning, consult qualified healthcare providers or specialized prevention clinics.

Section Navigation

PrEP Overview | Medication Types | Eligibility Criteria | Clinical Efficacy | Safety Profile | Key Takeaways