References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Antiretroviral (ARV) medications stop HIV from replicating in the body. Modern treatment uses a combination of drugs from different classes to attack the virus at multiple points in its life cycle. This approach — known as combination antiretroviral therapy (cART or ART) — has transformed HIV from a fatal diagnosis into a manageable long-term condition.
Here’s a clear guide to the main drug classes and how they work.
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How HIV Replicates
To understand how drugs work, it helps to know the steps HIV takes to make copies of itself:
- HIV attaches to a CD4 cell and enters it
- The virus converts its RNA into DNA (reverse transcription)
- The viral DNA is inserted into the cell’s DNA (integration)
- The cell makes new viral proteins
- New viral proteins are cut into functional pieces (protease)
- New virus particles are assembled and released
Each drug class blocks a different step.
Drug Classes
| Class | Abbreviation | How It Works | Examples |
|---|---|---|---|
| Nucleoside reverse transcriptase inhibitors | NRTIs | Block step 2 — fake DNA building blocks | Tenofovir, emtricitabine, lamivudine, abacavir |
| Non-nucleoside reverse transcriptase inhibitors | NNRTIs | Block step 2 — bind directly to the enzyme | Rilpivirine, efavirenz, doravirine, etravirine |
| Integrase strand transfer inhibitors | INSTIs | Block step 3 — prevent DNA insertion | Dolutegravir, bictegravir, cabotegravir, raltegravir |
| Protease inhibitors | PIs | Block step 5 — prevent protein cutting | Darunavir, atazanavir |
| Entry inhibitors | — | Block step 1 — prevent cell entry | Maraviroc, ibalizumab, fostemsavir |
| Pharmacokinetic boosters | — | Slow drug breakdown in the liver | Ritonavir, cobicistat |
How Combination Therapy Works
A standard HIV regimen uses drugs from at least two classes. This makes it much harder for the virus to develop resistance, because it would need to mutate against multiple drugs simultaneously. Modern regimens typically use:
- An INSTI + 1-2 NRTIs (most common first-line)
- An NNRTI + 2 NRTIs
- A boosted PI + 2 NRTIs
- Two-drug combinations (INSTI + NRTI, or INSTI + NNRTI)
Modern First-Line Options in the UK
- Biktarvy — bictegravir + emtricitabine + TAF
- Dovato — dolutegravir + lamivudine
- Triumeq — dolutegravir + abacavir + lamivudine
All are single-tablet, once-daily regimens.
Read more: Single-tablet treatments | HIV and the immune system | What is HIV?
Frequently Asked Questions
Why do I need more than one drug?
Using multiple drugs from different classes attacks HIV at multiple points, making it much harder for the virus to develop resistance.
Will I be on medication for life?
With current science, yes. There is no routine cure for HIV. Treatment keeps the virus suppressed but doesn’t eliminate it.
Are modern HIV drugs safe?
Modern ART is much better tolerated than older drugs. Most people have few or no side effects. Your HIV team monitors for any issues.
Related reading
- A to Z of Sex: Sexual Health Terms Explained
- Alcohol and HIV: What You Need to Know
- Anxiety and HIV: Coping and Getting Support
- Are All STIs Curable?
- Blood Problems and HIV: Anaemia, Low Platelets and More
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
