- Class
- Antitubercular drugs
- Body system
- Anti-infectives
What is Isoniazid used for?
- Active tuberculosis (with other drugs)
- Latent tuberculosis infection
How Isoniazid works
Blocks the synthesis of mycolic acid in the cell wall of Mycobacterium tuberculosis.
Common side effects
- Peripheral neuropathy
- Elevated liver enzymes
- Nausea
Report right away
- Loss of appetite, nausea, dark urine, yellow skin or eyes, fatigue (hepatitis): stop and call
- Numbness or tingling in hands or feet
Nursing considerations for Isoniazid
- Monitor liver function, especially in patients over 35, daily alcohol users, those with liver disease and during pregnancy or postpartum.
- Pyridoxine (vitamin B6) is given to prevent peripheral neuropathy in at-risk patients.
Patient teaching
- Take on an empty stomach, 1 hour before or 2 hours after a meal.
- Avoid alcohol.
- Treatment lasts months: take every dose; directly observed therapy may be used.
This card does not list doses. Use the prescriber's order, the product label and a current drug reference for dosing, and follow your facility's policies.
Antitubercular drugs practice questions
NCLEX-style questions on the class Isoniazid belongs to.
3 questions. Choose an answer to see the rationale.
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A patient taking rifampin is alarmed that their urine is orange. What should the nurse say?
Show answer
Answer A: This is an expected, harmless effect Rifampin colors urine, sweat and tears red-orange; it is harmless but can stain contact lenses.
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Which vitamin is given with isoniazid to prevent peripheral neuropathy?
Show answer
Answer C: Pyridoxine (vitamin B6) Isoniazid depletes pyridoxine; supplementation prevents neuropathy in at-risk patients.
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Which test should be done before starting ethambutol?
Show answer
Answer A: Visual acuity and color vision Ethambutol can cause optic neuritis with loss of visual acuity and red-green color discrimination.
Frequently asked questions
What is Isoniazid used for?
Active tuberculosis (with other drugs); Latent tuberculosis infection.
What drug class is Isoniazid?
Isoniazid (INH) belongs to the class antitubercular drugs. Blocks the synthesis of mycolic acid in the cell wall of Mycobacterium tuberculosis.
What are the nursing considerations for Isoniazid?
Monitor liver function, especially in patients over 35, daily alcohol users, those with liver disease and during pregnancy or postpartum. Pyridoxine (vitamin B6) is given to prevent peripheral neuropathy in at-risk patients.
What should patients report while taking Isoniazid?
loss of appetite, nausea, dark urine, yellow skin or eyes, fatigue (hepatitis): stop and call; numbness or tingling in hands or feet.