Which medication should the nurse avoid administering to clients who are taking nitrates?

Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor, primarily used to treat erectile dysfunction and pulmonary hypertension. When taken concurrently with nitrates, such as nitroglycerin, sildenafil can lead to a significant and potentially dangerous drop in blood pressure. Nitrates work by dilating blood vessels, increasing blood flow and lowering blood pressure, while sildenafil enhances the effects of nitric oxide in the body, which can further cause vasodilation. This combined effect may put patients at risk for severe hypotension, leading to dizziness, fainting, or even more serious cardiovascular events.

In contrast, the other medications listed do not carry this risk when used alongside nitrates. Lisinopril, an ACE inhibitor, is often prescribed for hypertension and heart failure. Simvastatin is a statin used to manage cholesterol levels, and albuterol is a bronchodilator for asthma and COPD. These agents do not interact negatively with nitrates in the same way that sildenafil does, making them safer options for patients who are being treated with nitrates.