Background: The first report for supplemental oxygen for angina was in 1900, and since then oxygen therapy has been a commonly used treatment of patients with ST-Elevation Myocardial Infarction (STEMI).  The reason for this is the belief that supplemental oxygen will increase oxygen delivery to ischemic myocardium and help reduce myocardial injury.  This belief is based off lab studies and older clinical trials, but there have been other studies that suggest potential adverse physiologic effects of supplemental oxygen in acute coronary syndromes (ACS) (i.e reduced coronary blood flow, increased coronary vascular resistance, and production of reactive oxygen species) causing vasoconstriction and reperfusion injury.

Background: Morphine is a commonly used medication in acute coronary syndromes (ACS) to help relieve pain which in turn can help reduce sympathetic tone.  Over the past few years however, there has been some concern raised about the drug-drug interactions with antiplatelet agents causing impaired platelet inhibition as well as an association with worsened clinical outcomes.  P2Y12 receptor antagonists (i.e. Clopidogrel, Pasugrel, Ticagrelor) are typically administered with aspirin (dual anti-platelet therapy) as one of the cornerstones of treatment for ACS.  This drug-to-drug interaction can cause delayed inhibition of platelet activation and potentially worsen clinical outcomes.

Background: Nitroglycerin is a first line agent in the treatment of ACS. The physiologic basis for it’s use rests on it’s ability to promote coronary vasodilation resulting in increased blood flow to the coronary arteries . Nitroglycerin, is typically given as sublingual tablets or sublingual spray of 0.3 – 0.4mg q5min x3 for ischemic chest pain and only after this is IV NTG given for persistent pain.

In 2011, Azithromycin was the 7th most prescribed (55.3 million prescriptions) medication according to IMS Health.  There have been several publications indicating that the use of macrolide antibiotics, increase risk of serious ventricular arrhythmias and sudden cardiac death (FDA Adverse Event Reporting System). Specifically, 2 recent studies in the NEJM were published looking at the risk of Azithromycin with cardiovascular death and received lots of press.