Which common medication should be discontinued prior to a CT scan with contrast due to the risk of lactic acidosis?

The medication that should be discontinued prior to a CT scan with contrast due to the risk of lactic acidosis is metformin. Metformin is a commonly prescribed medication for the management of type 2 diabetes. When iodine-based contrast agents are administered during imaging procedures like CT scans, there is a risk of acute kidney injury, particularly in patients with pre-existing renal impairment. This is concerning because impaired renal function can lead to an accumulation of metformin in the body.

In patients with decreased kidney function, the accumulation of metformin can lead to lactic acidosis, a serious and potentially life-threatening condition characterized by the buildup of lactic acid in the bloodstream. Therefore, it is a standard practice to hold metformin before procedures involving contrast to mitigate this risk.

In contrast, insulin, warfarin, and aspirin do not carry the same risk of lactic acidosis when performing a CT scan with contrast, making them safer to continue during such imaging studies. Insulin is crucial for glucose management in diabetic patients; warfarin is an anticoagulant that requires careful management but is not associated with lactic acidosis; and aspirin is used for its anti-inflammatory and antiplatelet effects without a direct link to lactic acid production in this