Pharmacology · Class
Integrase strand transfer inhibitors (INSTIs) !
They stop HIV DNA from being inserted into the cell's DNA. Dolutegravir is now the backbone of WHO-recommended treatment.
Updated 2026-11-01
What they are
Integrase strand transfer inhibitors: dolutegravir, bictegravir, raltegravir and cabotegravir. They lower viral load quickly, are well tolerated, and the second-generation agents (dolutegravir, bictegravir) have a high genetic barrier. WHO recommends dolutegravir as the preferred first- and second-line treatment for all populations.
Mechanism of action
Integrase trims the ends of viral DNA and then inserts it into the human chromosome (strand transfer). These drugs bind the two magnesium ions in the active site of the integrase-viral DNA complex (intasome) and block that step. Without integration, the virus cannot establish infection in the cell.
Target: HIV integrase (intasome), two-magnesium active site
Drugs in this class
- DolutegravirA high-barrier integrase inhibitor, the backbone of WHO's preferred treatment for all populations, including pregnant…HIV integrase (intasome)
- RaltegravirAn integrase inhibitor that is very well tolerated with few interactions, though its genetic barrier is lower than…HIV integrase (intasome)
- BictegravirA second-generation integrase inhibitor sold only in a single tablet with emtricitabine and tenofovir alafenamide.HIV integrase (intasome)
- CabotegravirAn integrase inhibitor available as a long-acting injection: it prevents HIV (PrEP) and, with rilpivirine, treats it…HIV integrase (intasome)
Others in the class
- Elvitegravir (with cobicistat)
Test yourself
Think of the answer, then tap the question to see it.
Which step of the HIV life cycle do INSTIs block?
Strand transfer: insertion of viral DNA into the cell's DNA.
Why can a magnesium antacid make an INSTI fail?
INSTIs bind metals; the antacid cation chelates them in the gut and greatly reduces absorption.
Why does creatinine rise on dolutegravir without worse kidney function?
Dolutegravir inhibits the tubular OCT2 transporter and reduces creatinine secretion; glomerular filtration does not change.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 64 (McGraw Hill, 2023); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); WHO recommends dolutegravir as preferred HIV treatment option in all populations (World Health Organization, 2019).
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Representative model, for educational purposes only.