Which drug is known for its potential to cause lactic acidosis as a side effect?

Lactic acidosis is a serious condition that arises from an accumulation of lactic acid in the body, often linked to certain antiretroviral medications used in the treatment of HIV. Among the options listed, tenofovir is recognized for its potential to cause significant metabolic side effects, including but not limited to lactic acidosis, particularly in its older formulation (tenofovir disoproxil fumarate). This risk is associated with mitochondrial toxicity, which can lead to a decrease in the body's ability to clear lactic acid.

While stavudine and didanosine are also antiretrovirals that have been associated with lactic acidosis in the past, they have largely fallen out of favor due to their more severe side effects and toxicity profiles. Emtricitabine, on the other hand, is not typically associated with lactic acidosis.

Tenofovir’s potential for causing lactic acidosis, especially in vulnerable populations or when combined with other medications that stress mitochondrial function, makes it a critical consideration for clinicians when prescribing and monitoring treatment regimens for patients on antiretroviral therapy. This understanding emphasizes the importance of patient monitoring for signs of lactic acidosis in those receiving tenofovir treatment.