Assignment task: The nurse is preparing to administer nitroglycerin to a patient. The nurse knows which of the following are correct? Select all that apply. Use with caution in hypotensive patients and in patients taking drugs that can lower blood pressure, including alcohol and antihypertensive medications. Contraindicated with sildenafil [Viagra] and other PDE5 inhibitors. Instruct patients to initially place the tablet or empty the powder under the tongue and then swallow with a full glass of water. Instruct patients to call 911 or go to an emergency department if pain is not relieved in 5 minutes following first dose during an acute attack. While awaiting emergency care, they can take 1 more dose, and then a third 5 minutes later. Therapeutic goal is reduction of the frequency and intensity of anginal attacks.