Delavirdine mesylate is primarily used in the treatment of HIV-1 infection. It functions as a non-nucleoside reverse transcriptase inhibitor (NNRTI), which helps to block the activity of reverse transcriptase, an enzyme crucial for the replication of the HIV virus. By inhibiting this enzyme, the drug reduces the viral load in the body and slows the progression of the disease. It is often prescribed as part of a combination antiretroviral therapy (ART) to enhance its effectiveness and minimize the risk of developing drug resistance. Delavirdine mesylate is particularly useful for patients who may not respond well to other NNRTIs or who require an alternative treatment option due to side effects or resistance issues. Proper adherence to the prescribed regimen is essential to achieve optimal therapeutic outcomes and maintain long-term viral suppression.