How does INH act against dormant Mycobacterium tuberculosis?

Isoniazid (INH) is known for its effectiveness in treating tuberculosis (TB), including both active and dormant forms of Mycobacterium tuberculosis. The mechanism of action of INH involves inhibition of mycolic acid synthesis, which is crucial for the bacterial cell wall. In dormant bacteria, which often exist in a non-replicating state in the body, INH still exerts its effect because it is primarily the structure and integrity of the cell wall that matter, rather than the active replication process.

This characteristic allows INH to penetrate and act on the mycobacteria even when they are not actively dividing, which is significant considering that dormant bacteria can lead to latent TB infections. Treating both active and dormant bacteria is crucial for comprehensive tuberculosis management, as it helps prevent reactivation of the disease and helps to reduce the overall burden of tuberculosis infections in populations.

The other options describe limitations that do not align with INH's capabilities. Some suggest that INH does not act on dormant forms or that it only enhances immune activity, which is not accurate in terms of its primary role as a bactericidal agent.