Which antiviral drug can cause lactic acidosis as a side effect?

NRTIs, or nucleoside reverse transcriptase inhibitors, are known to potentially cause lactic acidosis as a side effect. This is primarily due to their mechanism of action, which involves the inhibition of reverse transcriptase, an enzyme crucial for the replication of retroviruses such as HIV. The metabolism of these drugs can interfere with mitochondrial function, leading to an accumulation of lactic acid in the bloodstream—a condition known as lactic acidosis.

This side effect has been notably associated with drugs like zidovudine (AZT) and didanosine (ddI), which belong to the NRTI class. Clinical monitoring for symptoms of lactic acidosis, including fatigue, nausea, and abdominal pain, is an important aspect of patient management when prescribing these agents.

In contrast to NRTIs, the other classes such as protease inhibitors, integrase inhibitors, and fusion inhibitors have different mechanisms of action and side effect profiles that do not typically include lactic acidosis. For example, protease inhibitors may cause metabolic side effects such as hyperlipidemia, while integrase inhibitors are generally associated with fewer serious metabolic complications. Fusion inhibitors work by preventing viral entry and do not have a known link to lactic acidosis.