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[Pharmacology](https://durgical.com/en/pharmacology/) · Class

# Fixed-dose antiretroviral combinations

Two, three or more antiretrovirals in one tablet. Fewer pills mean better adherence and less risk of resistance.

Updated 2026-11-01

## What they are

Co-formulations of drugs from different classes that make up a complete regimen or its NRTI backbone. WHO promotes them to simplify public-health treatment; the combination of dolutegravir, lamivudine and tenofovir disoproxil (TLD) is the most widely used first-line regimen worldwide.

## Mechanism of action

Each component keeps its own mechanism. The combination hits the virus at two or more steps (for example reverse transcription and integration), so a single mutation is not enough for it to escape.

Target: Several HIV targets at once (reverse transcriptase, integrase, protease)

## Key points

- One tablet a day improves adherence, the main determinant of treatment success.
- Each component brings its own alerts: HLA-B*5701 with abacavir, kidney with tenofovir, hepatitis B with lamivudine, emtricitabine or tenofovir.
- If one component needs a kidney-function adjustment, the fixed tablet may no longer be suitable.
- Emtricitabine with tenofovir is also used as pre-exposure prophylaxis (PrEP).

## Drugs in this class

- [**Dolutegravir + lamivudine + tenofovir disoproxil (TLD)** A complete HIV regimen in one daily tablet: two NRTIs and an integrase inhibitor. It is WHO's preferred first line. HIV integrase (intasome)](https://durgical.com/en/pharmacology/dolutegravir-lamivudine-tenofovir-disoproxil/)

## Others in the class

- Abacavir + lamivudine
- Abacavir + dolutegravir + lamivudine
- Emtricitabine + tenofovir disoproxil
- Efavirenz + lamivudine + tenofovir disoproxil
- Efavirenz + emtricitabine + tenofovir disoproxil
- Lamivudine + zidovudine
- Bictegravir + emtricitabine + tenofovir alafenamide

## Test yourself

Think of the answer, then tap the question to see it.

## What is the main advantage of a fixed-dose combination?

It simplifies treatment and improves adherence, which reduces virological failure and resistance.

## Which components make up the TLD regimen?

Tenofovir disoproxil, lamivudine and dolutegravir: two NRTIs and an integrase inhibitor.

## Why does combining drugs from several classes prevent resistance?

The virus would need mutations against each mechanism at the same time, which is very unlikely when suppression is complete.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=J05AR) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [WHO recommends dolutegravir as preferred HIV treatment option in all populations](https://www.who.int/news/item/22-07-2019-who-recommends-dolutegravir-as-preferred-hiv-treatment-option-in-all-populations) (World Health Organization, 2019); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/) (World Health Organization, 2025).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/classes/fixed-dose-antiretroviral-combinations/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/classes/fixed-dose-antiretroviral-combinations/