 Day 11, pants review. Let's go. The question today is, you must hold metformin for blank amount of time after a procedure with IV contrast. I'm going to repeat that and give you a couple of seconds to think of an answer. So you must hold metformin. If your patient is on metformin, they're a type 2 diabetic. Excuse me. Usually that's why we prescribe metformin. You must hold metformin for blank some amount of time after a procedure involving IV contrast. OK. The answer is, you must hold metformin for 48 hours after a procedure involving IV contrast. The reason for this is if you do not hold metformin, you risk renal impairment and also an increase in metformin activity in the body, which can lead to lactic acidosis. All right, so one more time. How long must you hold metformin after a procedure using IV contrast, such as a cardiac catheterization, a CT with contrast, a CT angio, something like that? How long must you hold metformin after a procedure involving IV contrast? The answer is 48 hours. And the reason is if you don't hold metformin, you risk or you increase the risk for renal impairment and lactic acidosis due to increase in metformin activity in the body.