---
title: HIV Antiretroviral Therapy
description: A comprehensive clinical reference on the management of HIV with antiretroviral medications.
keywords: [HIV, antiretroviral therapy, ARV, CD4 count, viral load, HAART]
category: clinical
---

## Introduction to HIV Antiretroviral Therapy

Human immunodeficiency virus (HIV) is a retrovirus that attacks the body's immune system, specifically the CD4+ T cells, ultimately leading to acquired immunodeficiency syndrome (AIDS) if left untreated. Antiretroviral therapy (ART) is the cornerstone of HIV management, aiming to suppress viral replication, restore immune function, and prevent disease progression.

## Antiretroviral Medication Classes

The major classes of antiretroviral medications include:

1. Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTIs): Examples include tenofovir, emtricitabine, lamivudine, abacavir.
2. Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs): Examples include efavirenz, rilpivirine, nevirapine.
3. Protease Inhibitors (PIs): Examples include ritonavir, atazanavir, darunavir.
4. Integrase Strand Transfer Inhibitors (INSTIs): Examples include dolutegravir, raltegravir, elvitegravir.
5. Fusion Inhibitors: Examples include enfuvirtide.
6. CCR5 Antagonists: Examples include maraviroc.

## Antiretroviral Therapy Initiation and Regimen Selection

According to the Department of Health and Human Services (DHHS) HIV treatment guidelines, ART should be initiated in all individuals with HIV, regardless of CD4 count or clinical stage. The recommended initial regimens typically consist of two NRTIs plus an INSTI, NNRTI, or boosted PI.

The choice of initial ART regimen is based on factors such as:
- Viral load and CD4 count
- Comorbidities (e.g., renal or hepatic dysfunction, cardiovascular disease)
- Potential drug interactions
- Medication tolerability and patient preference

## Monitoring and Evaluation of ART

Ongoing monitoring of individuals on ART includes the following:

1. Viral load: The primary goal of ART is to achieve and maintain an undetectable viral load (<20 copies/mL).
2. CD4 count: CD4 count is used to assess immune function, with a goal of increasing or maintaining a CD4 count >500 cells/mm3.
3. Adverse effects: Regular assessment for potential side effects of ART, such as renal, hepatic, or metabolic abnormalities.
4. Adherence: Evaluation of medication adherence is crucial, as suboptimal adherence can lead to viral resistance.

## Antiretroviral Therapy Modifications and Resistance Management

In the event of virologic failure (defined as two consecutive viral loads >200 copies/mL), the following steps are recommended:

1. Assess for adherence barriers and address them.
2. Perform genotypic resistance testing to guide the selection of a new regimen.
3. Switch to a new ART regimen with at least two fully active medications, based on the resistance profile.

Strategies for managing ART resistance include using medications with high genetic barriers to resistance, such as boosted PIs or INSTIs, as well as incorporating novel drug classes.

## Special Populations and Considerations

1. Pregnancy: Specific ART regimens are recommended to prevent vertical transmission and ensure maternal health.
2. Pediatric patients: Dosing and formulations of ART medications are adjusted based on age and weight.
3. Older adults: Increased risk of comorbidities and drug interactions require careful ART selection and monitoring.
4. Hepatic or renal impairment: Dose adjustments or alternative regimens may be necessary based on organ function.

## Conclusion

Effective management of HIV with antiretroviral therapy is essential for improving clinical outcomes and quality of life for individuals living with HIV. Careful selection of ART regimens, close monitoring, and timely interventions for virologic failure or adverse effects are crucial components of comprehensive HIV care.