3. 8 Why ART needs combinations of drugs

HIV drugs need to be used in combinations. This is because no single drug is strong enough to fight HIV on it’s own.

This is why several drugs are used together.

• The first HIV drugs were not very potent. From roughly 1987 to 1993, each drug was used as single drug treatment. Any benefit was very short-term. Drug resistance also developed quickly.
• From 1994 to 1996, two-drug treatment were used. This was better than just using one drug, and benefits lasted a little longer. But drug resistance still developed.
• Since 1996, ART has used three or more drugs. This was strong enough to reduce HIV to undetectable and to keep it there. This greater potency reduced the risk of drug resistance.
• Since 2018, a few combinations use only two drugs. This is because the latest integrase inhibitors are much more potent than the first HIV drugs.

Using antiretroviral drugs together is called ART.

Some drugs combine several drugs into the same pill. Sometimes a whole combination is fitted into a once-daily pill.

In 2023, UK and US guidelines include ten combinations of oral ART in a single pill (and one combination of a long-acting injection).

In the UK however, drug prices mean that some of these combinations are only available as two separate pills. See: National HIV prescribing for England 2022: algorithms and policies

Generic HIV drugs are also available in single pill formulations. Some drug combinations are only available in generic formulations.

Last updated: 1 January 2023.