What laboratory tests might indicate potential hepatotoxicity in patients taking INH?

When monitoring patients taking isoniazid (INH), elevated liver enzymes, particularly alanine aminotransferase (ALT) and aspartate aminotransferase (AST), are critical indicators of potential hepatotoxicity. INH is known to potentially cause liver damage, and these enzymes are released into the bloodstream when liver cells are injured. Therefore, routine liver function tests that show an increase in ALT and AST levels signal that the liver may be undergoing stress or damage, prompting further assessment and possibly intervention.

The other choices pertain to different physiological aspects and do not specifically relate to the liver's function or the hepatotoxic effects of INH. Elevated blood glucose levels, while relevant in a broader medical context, are not direct indicators of liver injury. Similarly, a decreased white blood cell count can indicate various conditions but is not tied to hepatotoxicity from INH. Lastly, an increase in hemoglobin levels is also unrelated to liver function or toxicity and does not serve as a marker for liver damage. Therefore, monitoring ALT and AST levels is essential in identifying and addressing any potential hepatotoxic effects of INH.