Pharmacology · Integrase strand transfer inhibitors (INSTIs)
Raltegravir !
An integrase inhibitor that is very well tolerated with few interactions, though its genetic barrier is lower than dolutegravir's.
Updated 2026-11-01
Also called: RAL
The figure shows raltegravir bound to the prototype foamy virus (PFV) intasome, a retrovirus whose integrase shares the same two-magnesium active site as HIV's.
Mechanism of action
Like other INSTIs, it binds the magnesium ions in the active site of integrase bound to viral DNA and blocks strand transfer. It comes off the enzyme faster than dolutegravir, so fewer mutations are needed to defeat it.
- It binds the magnesium ions of the integrase active site
- Strand transfer is blocked
- Viral DNA is not integrated
Pharmacokinetics
- Metabolism
- Glucuronidation by UGT1A1; not dependent on cytochrome P450
Indications
- HIV-1 infection, combined with other antiretrovirals, in adults, children and newborns HIV infection and AIDS →
Adverse effects
Common
- Headache
- Insomnia
- Nausea
- Raised CK
Contraindications
- Previous hypersensitivity to raltegravir
Key interactions
- Rifampicin (UGT1A1 inducer)
- Lowers raltegravir: needs an adjustment ordered by the team
- Aluminium or magnesium antacids
- Greatly lower absorption: not recommended together
- Drugs that cause myopathy (for example statins)
- Higher risk of myopathy or rhabdomyolysis
What is monitored
- Viral load and CD4
- CK and muscle symptoms if myopathy risk
- Skin
Administration and safety
- By mouth; there are film-coated tablets, chewable tablets and granules for suspension, which are not interchangeable
- Separate antacids, calcium, iron and mineral-containing multivitamins in time, as the label directs
Nursing care
- Teach to report unexplained muscle pain or weakness
- Ask about antacids
- Check the correct product in children
Pregnancy and breastfeeding
Antiretroviral treatment in pregnancy protects the mother and lowers HIV transmission to the baby; the treating team chooses the regimen.
Test yourself
Think of the answer, then tap the question to see it.
Why does raltegravir have fewer interactions than PIs?
It is cleared by glucuronidation (UGT1A1) and does not depend on cytochrome P450.
Which muscle adverse effect can raltegravir cause?
Raised CK, myopathy and, rarely, rhabdomyolysis.
Why does raltegravir have a lower genetic barrier than dolutegravir?
It leaves the integrase-DNA complex faster, so fewer mutations are enough for it to lose effect.
Related drugs
Related conditions
← Back to the class: Integrase strand transfer inhibitors (INSTIs)
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - RALTEGRAVIR tablet, film coated (DailyMed (U.S. National Library of Medicine), 2026); Raltegravir: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025).
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Representative model, for educational purposes only.