Question 1

What is Isoniazid used for?

Accepted Answer

Tuberculosis (TB), TB prevention in people exposed to someone with active TB, latent TB infection (when you carry the TB germ but are not yet sick)

Question 2

How do you take Isoniazid?

Accepted Answer

For active TB treatment, the usual adult dose is 300 mg (one 300 mg tablet) taken once daily on an empty stomach — ideally 1 hour before food or 2 hours after eating. Your doctor will combine it with other TB drugs. For TB prevention, the dose is also 300 mg once daily, usually for 6 to 9 months. Always follow your doctor's exact instructions and never stop early even if you feel better.

Question 3

What are the side effects of Isoniazid?

Accepted Answer

Tingling or numbness in the hands and feet, mild nausea or stomach upset, feeling tired or weak, loss of appetite, mild skin rash

Question 4

Who should not take Isoniazid?

Accepted Answer

People who have had a serious allergic reaction to isoniazid before, anyone with active liver disease or a history of isoniazid-related liver damage, heavy alcohol drinkers with liver problems, and people with a history of severe drug-induced hepatitis.

Question 5

Is Isoniazid safe during pregnancy?

Accepted Answer

Isoniazid can be used during pregnancy and breastfeeding when your doctor decides the benefit of treating or preventing TB outweighs the risks — always consult your doctor before taking it.

Isoniazid

What is this drug?

What is it used for?

Quick Interaction Check