Used in the treatment of HIV infection as part of antiretroviral therapy. It works by inhibiting the reverse transcriptase enzyme, which is essential for viral replication. Stavudine helps reduce the amount of virus in the body, thereby improving immune function and delaying the progression of HIV to AIDS. Due to its side effect profile, including peripheral neuropathy and lipodystrophy, it is less commonly used today and has been largely replaced by safer alternatives in many countries. However, it may still be used in resource-limited settings due to its low cost and availability.