Integrase inhibitors, also known as integrase strand transfer inhibitors (INSTIs), are a class of antiretroviral drug designed to block the action of integrase, a viral enzyme that inserts the viral genome into the DNA of the host cell. Since integration is a vital step in retroviral replication, blocking it can halt further spread of the virus. Integrase inhibitors were initially developed for the treatment of HIV infection, but they could be applied to other retroviruses.
Since integrase inhibitors target a distinct step in the retroviral life cycle, they may be taken in combination with other types of HIV drugs to minimize adaptation by the virus. They are also useful in salvage therapy for patients whose virus has mutated and acquired resistance to other drugs.
Dolutegravir, brand name Tivicay, licensed by ViiV Healthcare, was approved by the FDA in 2013 and has recently gained European approval in January 2014. Dolutegravir is marketed as 50mg tablets as a once or twice daily add on to concurrent HAART therapy.