Which laboratory test should a nurse monitor monthly for a client receiving isoniazid?

Monitoring liver enzymes monthly for a client receiving isoniazid is essential due to the risk of hepatotoxicity associated with this medication. Isoniazid can lead to liver damage, which may present as asymptomatic elevations in liver enzymes or as clinically significant liver injury.

By regularly checking liver enzyme levels, the nurse can detect any early signs of liver impairment and intervene if necessary to prevent serious complications. The typical liver enzymes to monitor include alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as significant changes in these values can indicate whether the medication is adversely affecting the liver function.

This monitoring is particularly crucial in certain populations, such as older adults, those with pre-existing liver disease, or patients who consume alcohol, as they may be at a higher risk for developing hepatotoxicity. Therefore, regular assessment of liver enzymes helps ensure the safe and effective use of isoniazid in the treatment of tuberculosis.