3 Introduction to anti-retrovirals (ARVs)

3.5 How HIV drugs work – main types of drugs

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Like every living thing, HIV can reproduce itself. It does this inside CD4 cells. This involves many different stages. HIV drugs work by interfering with some of these stages.

The 6 classes of drugs are:

• Entry inhibitors (EIs), including fusion inhibitors and CCR5 inhibitors
• Nucleoside and nucleotide reverse transcriptase inhibitors (nukes or RTIs)
• Non-nucleoside reverse transcriptase inhibitors (non-nukes or NNRTIs)
• Integrase inhibitors (INIs)
• Protease inhibitors (PIs)
• Budding inhibitors (BIs)

Different drugs work at different stages of the HIV life cycle

• HIV uses CD4 cells as factories to make hundreds of copies of itself.
• Entry inhibitors work by stopping HIV getting into the CD4 cell.
• Nukes and non-nukes work by stopping one of the main ways HIV reproduces inside the CD4 cell.
• Integrase inhibitors work by stopping HIV from being integrated into the CD4 cell's DNA (genetic material).
• Protease inhibitors work by stopping any new HIV from being cut into smaller, manageable proteins.
• Budding inhibitors work by making new HIV that leaves the cell unable to infect new cells.