Isoniazid: Key Points & Mnemonic

Overview

• Isoniazid is a medication used to treat tuberculosis (TB).
• Can be used for:
  • Active TB
  • Latent TB
  • Prophylaxis for individuals exposed to TB.

Mnemonic Visual: Hotel Hallway with Ice Machine

• Ice Machine: Symbol for isoniazid ("ice").
• Pool Tubes: Symbol for tuberculosis ("tube" = tuberculosis).
  • Isoniazid inhibits mycobacterial cell wall synthesis.
  • Usually combined with other anti-TB drugs (e.g., rifampin).

Hepatotoxicity (Liver Damage)

• Lever (Liver):
  • Lever shaped like liver indicates hepatotoxicity.
  • Signs to monitor:
    • Jaundice
    • Nausea and vomiting
    • Dark-colored urine
  • Regularly check liver enzymes (AST and ALT).
  • Avoid concomitant use with other hepatotoxic agents (e.g., acetaminophen, alcohol).
  • Question if patient has existing liver damage.

Peripheral Neuropathy

• Frayed, Sparking Wire:
  • Symbol for neuropathy (damaged nerves).
  • Isoniazid can cause peripheral neuropathy (tingling in extremities).
  • Caused by deficiency in Vitamin B6.

Vitamin B6 (Pyridoxine)

• Breadsticks:
  • Symbol for Vitamin B6 ("B6" sounds like "breadsticks").
  • Isoniazid interferes with Vitamin B6 metabolism.
  • Supplementation with Vitamin B6 is needed to prevent neuropathy.

Recap

• Isoniazid treats active/latent TB and prophylaxis for exposed individuals.
• Hepatotoxic: Monitor for liver damage and avoid other hepatotoxic substances.
• Peripheral Neuropathy: Prevent by supplementing with Vitamin B6.

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