Pharmacology · Integrase strand transfer inhibitors (INSTIs)

Cabotegravir !

An integrase inhibitor available as a long-acting injection: it prevents HIV (PrEP) and, with rilpivirine, treats it with spaced injections.

Updated 2026-11-01

Class: Integrase strand transfer inhibitors (INSTIs)
Enzyme: HIV integrase (intasome)
ATC code: J05AJ04

Also called: CAB

HIV integrase (intasome)Cabotegravir

No structure with cabotegravir was found. The figure shows dolutegravir, its close structural analogue, which occupies the same two-magnesium site of the HIV-1 intasome.

Target in 3D: HIV integrase (intasome). PDB structure 8FN7 (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

A close analogue of dolutegravir: it binds the magnesium ions of the integrase active site and blocks integration of viral DNA. Its structure allows a nanocrystal formulation for intramuscular injection that releases drug over weeks.

It is released slowly from the intramuscular depot
It binds the magnesium ions of the integrase active site
Integration of viral DNA is blocked

Pharmacokinetics

Absorption: Oral (with food) or long-acting intramuscular
Metabolism: Mainly by UGT1A1
Half-life: The injectable lasts weeks and can be detected in blood more than a year after the last injection

Indications

Prevention of HIV-1 infection (injectable PrEP) HIV infection and AIDS →
Treatment of suppressed HIV-1 infection, with injectable rilpivirine HIV infection and AIDS →

Adverse effects

Common

Injection-site reactions (pain, swelling, nodules) in most people
Fever, tiredness, headache
Nausea, abnormal dreams, anxiety, insomnia

Contraindications

Previous hypersensitivity to cabotegravir
Use as PrEP without a negative HIV test

Key interactions

Rifampicin and other strong UGT1A1 inducers: Lower cabotegravir with risk of failure
Calcium, magnesium or aluminium antacids (oral form): Lower absorption of oral cabotegravir: doses are separated

What is monitored

Negative HIV test before each PrEP injection
Symptoms of acute HIV infection
Mood
Liver tests

Administration and safety

The injectable is given intramuscularly in the buttock by health staff
Keep to the appointment schedule: a long delay leaves low levels and a resistance risk
It may start with an oral phase to check tolerance

Nursing care

Confirm a negative HIV test before each PrEP injection
Check the injection site and teach to recognise reactions
Record the next appointment date and ask to be told of any delay
Ask about depressive symptoms

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.

Which test is needed before each PrEP cabotegravir injection, and why?

A negative HIV test: if the person already has HIV, cabotegravir alone would select INSTI-resistant virus.

What is the pharmacokinetic 'tail' of injectable cabotegravir?

After stopping, levels fall very slowly over months; if HIV is acquired then, resistance can emerge.

Which drug is injectable cabotegravir combined with to treat HIV?

With long-acting injectable rilpivirine.

Add to my cards (3)

HIV infection and AIDS

← 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: Cabotegravir Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); Cabotegravir: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); HIV and AIDS (World Health Organization, 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 64 (McGraw Hill, 2023).

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Representative model, for educational purposes only.