A Review on FDA Approved Antiretroviral Drugs for the treatment of HIV

Antiretroviral drugs are medicines used to treat infections caused by retroviruses, especially HIV (Human Immunodeficiency Virus). They work by blocking different stages of the viral replication cycle, thereby reducing the amount of virus in the body (viral load), increasing CD4 cell count, and preventing progression to AIDS.

AIDS (acquired immunodeficiency syndrome)

Fig no. 1: AIDS symbol

AIDS is a life-threatening condition caused by the Human Immunodeficiency Virus (HIV).

HIV attacks and weakens the body’s immune system, especially CD4 (T-helper) cells, making it hard to fight infections and certain cancers.

If untreated, HIV infection gradually progresses to AIDS, the final stage of the disease.

• Symptoms

Symptoms vary depending on the stage:

1. Early Stage (Acute HIV Infection, 2–6 weeks after exposure):
   • Fever
   • Sore throat
   • Rash
   • Swollen lymph nodes
   • Headache & body aches (flu-like illness)

Latent Stage (Clinical Latency, can last years):                

Often no major symptoms   Virus still multiplies slowly

2. AIDS Stage (Severe Immunodeficiency):
   • Rapid weight loss
   • Persistent fever and night sweats
   • Chronic diarrhea
   • Persistent cough / tuberculosis
   • White patches in mouth (oral thrush)
   • Skin rashes or unusual spots (Kaposi’s sarcoma)
   • Frequent infections (pneumonia, fungal, viral)

Method of treatment:

Each ART medicines restrict HIV at a various part of the Virus replication mode . For better knowledge about action of ART therapy must understand that how HIV infects the human cells & grows. Shortly like someone breaking into your house & reprogramming your security system so other to other introducer can get in.

During the condition HIV gets present inside your cells, writes instructions to makes  copies of itself and uses your cells tools to form more copies of them. Not only it destroyed T-Cell during the processing as well preventing you from being able to fight some other infectious diseases.

Here also the specific steps involves with mechanisms:

• Attachment

HIV uses a protein GP120 to attach the receptor on our CD4 cells i.e. Immune cells. Receptors like locks HIV should began to enter the healthy cells. This is continuous step in which involves the changing of proteins shapes and locking on to more than one receptors.

• Fusion

The external coating of HIV join with the CD4 cell & this is called as Fusion.

• Entry

The capsid Of Virus: a shell made up of proteins carries its genetic material & tools it needs to replicate, get inside now.

• Reverse transcription

An enzyme HIV carries , ,makes DNA from RNAs and build the DNA from building blocks found inside your cells (nucleosides).

• Integration

 HIV’s DNA gets into the nucleus of the cell , where DNA lives .There are the enzymes integrated inserts the HIV DNA into your DNA. From it your cells read the virus’s DNA as if they were your own body’s instructions. 

• Transcription

Your cell codes its DNA and HIV’s DNA into messenger RNA (m RNA)s .

• Translation

The mRNA moves outside of the nucleus and uses your cell’s ribosomes ( similar to tiny factories that make proteins) to create proteins from its instructions. The mRNA moves outsides of the nucleus and uses your cell’s ribosomes to synthesized proteins from its instructions. Proteins are a important part of your body which play vital roles.

• Assembly

HIV proteases break these proteins apart and packages them into more viruses to infect other cells. 

• Budding and cell death

The CD4 cell is destroyed when the viruses escape the cell to infect more cells.

Fig no. 2: mechanisms of HIV drugs

Fig. no. 3: Antiretroviral drugs

Classes of Antiretroviral Drugs: -

1. Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTIs)

Block reverse transcriptase enzyme by mimicking DNA building blocks → prevents viral DNA formation.

1. • Examples: Zidovudine (AZT), Lamivudine (3TC), Tenofovir (TDF), Abacavir (ABC), Emtricitabine (FTC).
2. Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)

Bind directly to reverse transcriptase and block its activity (different mechanism than NRTIs).

2. • Examples: Efavirenz (EFV), Nevirapine (NVP), Etravirine, Rilpivirine.
3. Protease Inhibitors (PIs)

Inhibit HIV protease enzyme → prevents virus from maturing and becoming infectious.

3. • Examples: Ritonavir (RTV), Lopinavir, Atazanavir, Darunavir, Indinavir.
4. Integrase Strand Transfer Inhibitors (INSTIs)

Block integrase enzyme → stops viral DNA from inserting into host cell DNA.

4. • Examples: Raltegravir, Dolutegravir, Elvitegravir, Bictegravir.
5. Fusion Inhibitors

Prevent HIV from fusing with the host cell membrane → virus cannot enter CD4 cells.

5. • Example: Enfuvirtide (T-20).
6. CCR5 Antagonists (Entry Inhibitors)

Block the CCR5 co-receptor on CD4 cells, stopping viral entry.

Example: Maraviroc.

Standard Treatment Approach

Treatment is called ART (Antiretroviral Therapy) or HAART (Highly Active Antiretroviral Therapy).

Usually a combination of 3 drugs from at least 2 different classes.

• • Example regimen: Tenofovir + Lamivudine + Dolutegravir (TLD regimen) (commonly used worldwide).

Benefits of ART: -

• • Suppresses HIV replication.
  • Prevents progression to AIDS.
  • Improves quality of life and life expectancy.
  • Reduces mother-to-child transmission and sexual transmission.

Side Effects: - Nausea, diarrhea, headache.

Long-term: liver damage, kidney problems, lip dystrophy (fat distribution changes). Modern regimens have fewer and

Milder side effects: Extreme fatigue

• Treatment: -

There is no permanent cure for AIDS, but it can be controlled with treatment.

1. ART (Antiretroviral Therapy):

Combination of medicines that reduce the viral load, keep immune system stronger, and prevent progression to AIDS.

Life long treatment.

1)Supportive Care:

Preventing and treating opportunistic infections (antibiotics, antifungals, antivirals). Vaccinations (non-live vaccines where safe).

Good nutrition and healthy lifestyle.

• Prevention: -
• Safe sex practices (condoms).
• Avoid sharing needles.
• HIV testing and early treatment.
• Preventing mother-to-child transmission during pregnancy.

LIST OF FDA APPROVEC ANTIRETROVIRAL DRUGS WITH THEIR BRAND NAME{Listed below are all FDA-approved HIV medications as of July 3, 2025}