A patient on prolonged broad-spectrum antibiotics develops prolonged PT. Which biochemical defect is responsible?
1). Reduced fibrinogen synthesis
2). Failure of γ-carboxylation of glutamate residues
3). Defective collagen synthesis
4). Reduced platelet production
📝 Explanation:
Antibiotics reduce intestinal vitamin K production, impairing γ-carboxylation of vitamin K-dependent clotting factors II, VII, IX, and X.