If a client presents with symptoms of tachycardia and chest pain, what is the initial medication the nurse should administer?

The initial medication that should be administered in the case of a client presenting with tachycardia and chest pain is sublingual nitroglycerin. This choice is correct because nitroglycerin is a vasodilator that can rapidly relieve chest pain, especially if it is angina or related to myocardial ischemia. By relaxing and dilating the blood vessels, nitroglycerin decreases the workload on the heart and improves blood flow, which helps alleviate both chest pain and tachycardia.

Other options are less appropriate in this scenario. Morphine sulfate may be used later to manage pain and anxiety associated with acute coronary syndrome but is not the first-line treatment for chest pain. Likewise, IV dilaudid, a potent opioid, is also not typically an initial response to chest pain without prior measures to assess the situation fully. Oral atorvastatin, while important for long-term management of cholesterol levels, does not provide immediate relief for the acute symptoms of tachycardia and chest pain. Therefore, sublingual nitroglycerin is the most appropriate initial intervention for this presentation.