What guidelines exist for monitoring liver function tests in patients receiving INH?

Monthly monitoring during the first three months of therapy with isoniazid (INH) is a guideline that reflects the risk of hepatotoxicity associated with this medication. The liver function tests (LFTs) are particularly important during this initial phase because hepatic injury can manifest in the early stages of treatment, often within the first few weeks to months.

Monitoring monthly allows for timely identification of any elevations in liver enzyme levels and helps to ensure patient safety. Should abnormalities arise, healthcare providers have the opportunity to intervene early, either by adjusting the medication dosage or discontinuing INH altogether to prevent more severe liver damage.

Subsequent liver function tests may become less frequent after the first three months if no issues are detected, but the initial close monitoring is critical due to the potential for severe adverse effects. Other options suggest varying frequencies or timelines that do not align with the established guidelines for optimal patient safety in the use of INH.