Integrase Strand Transfer Inhibitors (INSTIs) are a class of antiretroviral drugs used to treat HIV infections. They work by blocking the action of the enzyme integrase, which is crucial for the virus to insert its genetic material into the host's DNA. By inhibiting this process, INSTIs help prevent the replication of the virus in the body. Common examples of INSTIs include raltegravir, elvitegravir, and dolutegravir. These medications are often preferred due to their effectiveness, favorable side effect profiles, and once-daily dosing options. They are typically used as part of a combination therapy to achieve better control of the virus.