Which medication should be discontinued for a patient taking atenolol and sublingual nitroglycerin?

The appropriate medication to discontinue for a patient taking atenolol and sublingual nitroglycerin is sildenafil. This is primarily due to the potential for a dangerous interaction between sildenafil and nitrates like nitroglycerin. Both medications can lead to significant vasodilation, which may cause profound hypotension (low blood pressure). When sildenafil is taken in conjunction with nitrates, the additive effects can place the patient at risk of severe cardiovascular complications, including syncope (fainting) and even heart attack.

Atenolol, being a beta-blocker, helps manage heart rate and blood pressure, while amlodipine is a calcium channel blocker that is also used for hypertension and angina. Metformin is an antidiabetic medication, and lisinopril is an ACE inhibitor often prescribed for hypertension or heart failure. None of these medications have the same severe interaction risk with nitroglycerin as sildenafil, making it the medication that should be discontinued in this scenario.