A nurse is reviewing a list of current medications for a client who is starting therapy with furosemide. Which of the following medications should the nurse identify as being contraindicated?

A. Levothyroxine. Levothyroxine is used to treat hypothyroidism and does not have a significant interaction with furosemide. However, both medications require careful monitoring, as hypothyroidism can affect fluid balance, but they are not contraindicated together. B. Cetirizine. Cetirizine is an antihistamine used to treat allergies and does not interfere with furosemide’s effects. While some antihistamines can cause mild fluid retention, this does not significantly impact furosemide therapy, making them safe to use together. C. Lithium carbonate. Furosemide is a loop diuretic that increases sodium excretion. Since lithium is excreted through the kidneys in a sodium-dependent manner, a loss of sodium due to diuretic use can lead to reduced lithium excretion and toxic accumulation. Clients taking lithium should avoid diuretics unless absolutely necessary, and their lithium levels must be carefully monitored if diuretics are required. D. Albuterol. Albuterol is a bronchodilator used for conditions like asthma and COPD. While both furosemide and albuterol can cause hypokalemia, this does not make them absolutely contraindicated. Instead, potassium levels should be regularly monitored, and supplementation may be needed if hypokalemia develops.