Abacavir sulfate is primarily used in the treatment of HIV infection. It is an antiretroviral medication that works by inhibiting the reverse transcriptase enzyme, which is essential for the replication of the HIV virus. This helps to reduce the viral load in the body and improves the immune system function. It is often prescribed as part of a combination therapy regimen, known as highly active antiretroviral therapy (HAART), to enhance its effectiveness and minimize the risk of developing drug resistance. Patients taking this medication must be monitored for potential hypersensitivity reactions, which can be severe. It is crucial for healthcare providers to screen for the HLA-B*5701 allele before initiating treatment, as individuals with this genetic marker are at a higher risk of adverse reactions.