Before administering isoniazid (INH) therapy for tuberculosis, which baseline study is crucial for nurses to check?

The crucial baseline study to check before administering isoniazid (INH) therapy for tuberculosis is liver enzyme levels. Isoniazid is known to potentially cause hepatotoxicity, which can lead to liver damage. Monitoring liver enzyme levels, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), is essential to ensure the patient's liver function is safe for therapy. Elevated liver enzymes can indicate liver damage or stress, and detecting this early allows for appropriate management.

While coagulation times, electrolyte levels, and serum creatinine levels are important for overall patient safety and may be monitored during various treatments, they do not carry the same level of direct relevance to the safety of initiating isoniazid therapy as liver enzyme levels do. Understanding the specific risks associated with isoniazid highlights the necessity of this particular baseline study.