💊

Rifampin Overview and Action

Aug 17, 2025

Overview

This lecture focuses on Rifampin, an antibiotic that inhibits nucleic acid synthesis in bacteria, especially for treating tuberculosis (TB).

Rifampin Overview

  • Rifampin belongs to the rifamycin class and is a semisynthetic antibiotic.
  • It is effective against gram-positive and some gram-negative bacteria.
  • Rifampin is mainly used to treat mycobacterium tuberculosis, the bacterium causing tuberculosis (TB).
  • It can reach and kill TB bacteria hiding inside macrophages during latent infections.
  • Rifampin is primarily used in combination with other drugs for TB treatment.

Mechanism of Action

  • Rifampin inhibits the bacterial enzyme RNA polymerase, preventing the conversion of DNA into RNA.
  • Human and bacterial RNA polymerases are structurally different, so Rifampin is selectively toxic to bacteria.

Side Effects and Monitoring

  • Rifampin may cause elevated liver enzymes, requiring regular liver function monitoring during TB treatment.
  • TB treatment with Rifampin is long-term, increasing the importance of ongoing monitoring.
  • Rifampin causes harmless orange-red discoloration of body fluids (urine, sweat, semen, etc.).

Key Terms & Definitions

  • Rifamycin — Class of antibiotics to which Rifampin belongs.
  • Mycobacterium tuberculosis — Bacteria that causes tuberculosis.
  • RNA polymerase — Enzyme that transcribes DNA into RNA; target of Rifampin.
  • Selective toxicity — Drug affects microbes but not human cells.

Action Items / Next Steps

  • Monitor liver function tests regularly during Rifampin treatment.
  • Expect orange-red discoloration of body fluids as a side effect.
  • Watch for upcoming lectures on other anti-tubercular drugs.