Final answer:
To prevent peripheral neuropathy caused by isoniazid (INH) in a TB treatment regimen, it is advisable to order pyridoxine (vitamin B6) prophylactically. Pyridoxine helps to offset the potential deficit caused by INH, thereby reducing the risk of neuropathy.
Step-by-step explanation:
Marci has been started on a TB regimen and to mitigate the risk of peripheral neuropathy caused by isoniazid (INH), it is recommended to prophylactically order pyridoxine (vitamin B6). INH can cause a deficiency of vitamin B6 because of its structural resemblance to the vitamin. Pyridoxine is essential for the prevention and treatment of peripheral neuropathy, a potential side effect associated with INH treatment. Other options such as thiamine, probiotics, and phytonadione are not directly related to the prevention of INH-induced peripheral neuropathy. Therefore, administering pyridoxine alongside INH is a common practice to reduce the risk of this side effect, improving the safety of tuberculosis treatment protocols.