Why is isoniazid is prescribed for latent tb?

See below: Isoniazid is used alone or with other drugs to treat tuberculosis (TB) and to prevent it in people who have had contact with tuberculosis bacteria. It eliminates only active (growing) bacteria. Since the bacteria may exist in a resting (nongrowing) state for long periods, therapy with Isoniazid (and other antituberculosis drugs) must be continued for a long time (usually 6-12 months).

Related Questions

How can I know if isoniazid worked after I've finished my 6-month treatment for latent tb?

Followup with doc. Followup with your treating physician or regional health authority is your best plan. They may have a protocol to follow with scheduled repeat x-rays or other studies, the timing of which will vary.

If you have Latent TB (skin and blood test positive), and got treated for it with isoniazid for 9 months - can you still get active TB?

TBC. If you have Latent TB (skin and blood test positive), and got treated for it with isoniazid for 9 months - can you still get active TB? ANS: it is always possible to get TB again or for the old walled off TB bugs to become active again. Esp if your immune system becomes impaired such as taking steroids or get HIV.

I am 36/Male/Indian origin. In US for 10 yrs. Diagnosed with Latent TB. Visit Asia frequently. My Doctor advised 9 month isoniazid. Is it effective?

Yes. Completing a 9-month course of isoniazid reduces your lifetime chance of progressing to active TB by 90% (lowers it from a 5-10% chance to under 1%). A 3-month course of weekly isoniazid + rifapentin is more expensive but has the same effectiveness as the 9-month course of isoniazid only. Both types of treatment are effective.