What lab tests should be conducted before initiating INH therapy?

Liver Function Tests (LFTs) are essential before initiating isoniazid (INH) therapy because INH is metabolized in the liver and has the potential to cause hepatotoxicity. Monitoring liver function prior to treatment helps to establish a baseline and assess the risk of liver injury as the therapy progresses. This is particularly important since certain populations, such as those with pre-existing liver conditions or those who consume alcohol regularly, may be at a higher risk for adverse effects.

Conducting LFTs can help identify patients who may not tolerate INH well and enable healthcare providers to make informed decisions about the safety and appropriateness of this medication. Regular monitoring of liver enzymes during therapy is also critical to detect any potential liver damage early on, further underscoring the importance of this lab test prior to treatment.

Other tests, while important in different contexts, do not specifically address the primary concern associated with INH therapy. Coagulation profiles, kidney function tests, and complete blood counts are not as closely linked to the risks associated with INH initiation as liver function tests are.