Final answer:
Avoid administering nitroglycerin to a patient who has taken Viagra (sildenafil nitrate) within the last 12 hours, due to the risk of severe hypotension caused by the combined vasodilatory effects of both drugs.
Step-by-step explanation:
You should avoid giving nitroglycerin to a patient that admits to taking Viagra (sildenafil nitrate) in the last 12 hours. The combination of nitroglycerin, which is a nitrate, and sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, can lead to severe hypotension (low blood pressure) due to excessive vasodilation. This is because both drugs potentiate the effects of nitric oxide in the body, which leads to vasodilation and can greatly lower blood pressure. This might cause collapse, unconsciousness, or even a life-threatening situation. Therefore, a patient on Viagra should be extremely cautious and generally should not be given nitroglycerin.
As for the other patients mentioned, such as those with a heart rate of 60 bpm, a systolic blood pressure of 98 mmHg, or experiencing an anterolateral infarction, nitroglycerin may still be considered for use with close monitoring and professional judgement, as it helps to relieve chest pain and improve blood flow to the heart muscle during a myocardial infarction (heart attack).