Amiodarone belongs to Vaughan-Williams class III but also has properties of classes I, II, and IV. Its most dangerous long-term adverse effect requiring regular monitoring is:

• A Lupus-like syndrome
• B Agranulocytosis
• C Gingival hyperplasia
• D Pulmonary toxicity (amiodarone pneumonitis/fibrosis) ✓

Explanation

Amiodarone's most serious and potentially fatal long-term toxicity is pulmonary — amiodarone pneumonitis progressing to fibrosis, occurring in 1–5% of patients. Mechanistically, it accumulates in lung parenchyma and induces phospholipidosis, resulting in inflammatory infiltrates. Chest X-ray, PFTs, and HRCT are monitored periodically. Other notable toxicities include thyroid dysfunction (hypo and hyperthyroidism), hepatotoxicity, photosensitivity (blue-grey discolouration), corneal microdeposits, and peripheral neuropathy. Lupus is a class IA (procainamide) adverse effect.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.