A client is scheduled to for a CT scan with lodine contrast this morning. The nurse knows to withhold which medication to prevent acute kidney injury?

Rationale: A. Loratadine: Loratadine is a second-generation antihistamine used to treat allergic symptoms and does not have nephrotoxic effects or interactions with iodinated contrast media. It does not affect renal perfusion or lactic acid metabolism, so there is no indication to withhold it prior to a CT scan with contrast. B. Insulin: Insulin regulates blood glucose by facilitating cellular uptake of glucose and does not pose a risk for contrast-induced nephropathy or lactic acidosis. Maintaining glycemic control is important, especially during procedures, so insulin is generally continued with monitoring rather than withheld. C. Levothyroxine: Levothyroxine is a thyroid hormone replacement that supports normal metabolic activity and does not adversely interact with iodinated contrast in a way that increases kidney injury risk. While iodine can affect thyroid function, withholding levothyroxine is not necessary for renal protection. D. Metformin: Metformin is associated with a risk of lactic acidosis, particularly in renal impairment. Iodinated contrast can reduce renal function transiently, leading to accumulation of metformin and increased risk of lactic acidosis, which can be life-threatening. For this reason, metformin is withheld before and after contrast administration until renal function is stable.