Question

1. Maria is a 19-year-old exchange student from Brazil. She was started on daily isoniazid (INH) 4 months ago for latent tuberculosis (TB). She would like to be seen at your clinic now because it is closer to school. She has not taken her medication for 4 weeks and cannot recall when her labs were drawn last. She has no other health history and does not take any other medications. According to the national guidelines, how long would Maria likely need to take INH? Can she restart her medication even though she has been off for 1 month? How often should she be seen for follow-up? What are the black box warnings of INH?

Answer 1

1) According to National guidelines Maria need to take ISONIAZID (INH) monotherapy for 6 or 9 months (9 months regimen is preferred by most of the physician)

2) yes, she can restart the medication but prior to that :

• Her liver enzymes must be checked to assess the function of liver (as INH is hepatotoxic)
• Laboratory tests should be performed and asess the state of infection (it might have progressed to active state as she stopped taking INH)
• Bacteria might have developed RESISTANCE to INH as she did not complete the whole course of medication.So, bacterial sensitivity should be checked.

3) She should see a doctor atleast once in a month to assess the function of her liver (as INH is hepatotoxic)

4) Avoid taking alcohol with isoniazid. Severe,sometimes fatal hepatitis may occur because of this drug so patient should be informed about the signs of hepatitis.

Medications which are hepatotoxic should be avoided