Stavudine (d4T), sold under the brand name Zerit among others, is an antiretroviral medication used to prevent and treat HIV/AIDS. It is generally recommended for use with other antiretrovirals. It may be used for prevention after a needlestick injury or other potential exposure. However, it is not a first-line treatment. It is given by mouth. Common side effects include headache, diarrhea, vomiting, rash, and peripheral nerve problems. Severe side effects include high blood lactate, pancreatitis, and an enlarged liver. It is not generally recommended in pregnancy. Stavudine is in the nucleoside analog reverse-transcriptase inhibitor (NRTI) class of medication. Stavudine was first described in 1966 and approved for use in the United States in 1994. It is available as a generic medication. Medical uses Stavudine is used in the treatment of HIV-1 infection, but is not a cure. It is not normally recommended as initial treatment. Stavudine can also reduce the risk of developing HIV-1 infection after coming into contact with the virus either at work (e.g., needlestick) or through exposure to infected blood or other bodily fluids. It is always used in combination with other HIV medications for the better control of the infection and a reduction in HIV complications. The World Health Organization (WHO) recommends stavudine to be phased out to due to its high toxicity levels. If the drug must be used, it is recommended to use low dosages to reduce the occurrence of side effects; however, a 2015 Cochrane review found no clear advantage between high and low dosage regimens. Pregnancy and breastfeeding Stavudine has been demonstrated to affect the fetus in animal studies but no data are available from human studies. Pregnant women should therefore be given stavudine only if the potential benefits outweigh the potential harm to the fetus. Additionally, there have been case reports of fatal lactic acidosis in pregnant women receiving combination therapy of stavudine and didanosine with other antiviral agents. The Centers for Disease Control and Prevention recommend that HIV-infected mothers not breastfeed their infants, in order to avoid the risk of HIV transmission through breast milk. There is also evidence that stavudine gets into animal breast milk, although no data are available for human breast milk. Children Stavudine is safe for use in children infected with HIV from birth through adolescence. Adverse effects and safety profile are the same as adults. Elderly There is no data available for stavudine use in