What is the mechanism of action of rifamycins (such as rifampin)?

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Multiple Choice

What is the mechanism of action of rifamycins (such as rifampin)?

Rifamycins work by binding to the bacterial DNA-dependent RNA polymerase, specifically the beta subunit, and blocking transcription. This prevents RNA synthesis from starting and halts the production of mRNA, effectively stopping gene expression and bacterial growth. The enzyme targeted is distinct in bacteria, so the drug is selectively toxic to bacteria rather than human cells. Resistance typically develops through mutations in the rpoB gene that change the rifampin binding site on the polymerase. Clinically, this class is important for treating Mycobacterium infections (like TB) and other bacteria, but they can cause drug interactions due to enzyme induction and have a risk of resistance if used alone.

Rifamycins work by binding to the bacterial DNA-dependent RNA polymerase, specifically the beta subunit, and blocking transcription. This prevents RNA synthesis from starting and halts the production of mRNA, effectively stopping gene expression and bacterial growth. The enzyme targeted is distinct in bacteria, so the drug is selectively toxic to bacteria rather than human cells. Resistance typically develops through mutations in the rpoB gene that change the rifampin binding site on the polymerase. Clinically, this class is important for treating Mycobacterium infections (like TB) and other bacteria, but they can cause drug interactions due to enzyme induction and have a risk of resistance if used alone.

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