Vit 6:01 Q Overview on Isoniazid and Rifampin in Tuberculosis Treatment

What is the primary site of action of Isoniazid (INH)?

Which type of bacilli does Rifampin (RIF) primarily work on?

What is the clinical use of Rifampin (RIF) in addition to treating TB?

Which adverse drug reaction (ADR) is associated with Isoniazid (INH) and requires Pyridoxine supplementation?

Why is Vitamin B6 prescribed with Isoniazid (INH)?

When is hepatitis caused by Isoniazid (INH) more likely to occur?

What is the main mechanism of action of the drug described in the text?

Which side effect is NOT associated with the drug?

What is the consequence of being a fast acetylator of the drug?

Which vitamin is affected by the drug's inhibition of pyridoxine?

What enzyme isoforms are strongly induced by the drug?

What type of infection can the drug be used to treat besides TB?

Isoniazid (INH)

First-line treatment for tuberculosis
Bacteriostatic, effective against resting bacilli
Inhibits the synthesis of mycolic acid, a key component of mycobacterial cell wall
Penetrates into macrophages
Clinical uses:
- Treatment of TB
- Treatment of Latent TB in patients with positive tuberculin skin test
- Prophylaxis against active TB in high-risk individuals
Adverse drug reactions (ADRs):
- Peripheral neuritis (pins and needles sensation in the feet)
- Optic neuritis and atrophy
- Hepatitis (toxic metabolites, age-dependent, and increased with alcohol use)
Interactions:
- Inhibits cytochrome P450 2C19 isoform, leading to accumulation of drugs metabolized by 2C19
- Slow and fast acetylators: genetic variation affects metabolism and toxicity

Rifampin (Rifampicin)

Bactericidal, effective against rapidly growing bacilli
Inhibits RNA synthesis by binding to bacterial DNA-dependent RNA polymerase enzyme
Clinical uses:
- Treatment of TB
- Prophylaxis against meningococcal and staphylococcal infections
Adverse drug reactions (ADRs):
- Harmless red-orange discoloration of body secretions (saliva, sweat, urine, tears)
- Hepatitis (less common compared to INH)
- Flu-like syndrome
- Hemolytic anemia
Interactions:
- Strongly induces most cytochrome P450 isoforms (2C19, 2C9, 3A4)
- Clinically significant drug interactions: warfarin, methadone (faster metabolism, reduced activity)

This quiz provides an overview of Isoniazid (INH) and Rifampin (RIF) in the treatment of tuberculosis, including their mechanisms of action, clinical uses, adverse drug reactions, and drug interactions. Test your knowledge on the first-line treatments for TB!