Which medication should be held after a patient received IV contrast for a CT scan?

The appropriate medication to hold after a patient receives IV contrast for a CT scan is metformin (Glucophage). This is due to the potential risk of lactic acidosis, a serious condition that can occur when metformin is combined with the stress of IV contrast, especially in patients with reduced renal function. The administration of IV contrast can impact kidney function, and since metformin is primarily eliminated by the kidneys, impaired renal function increases the risk of metformin accumulation in the body.

Holding metformin reduces the risk of complications related to potential contrast-induced nephropathy, which can lead to further renal impairment and exacerbate the risks associated with metformin. It is generally advised to withhold metformin for at least 48 hours after the administration of IV contrast to ensure the patient's renal function is stable before resuming the medication. This precaution helps protect patient safety and ensure appropriate management of diabetes.

Other medications listed, such as amoxicillin, ibuprofen, and levothyroxine, do not have the same direct connection to complications arising from the use of IV contrast, making them less of a priority to hold in this context.