Which medications are classified as nitrates for treating angina episodes?

Nitrates are a class of medications primarily used to alleviate angina, which is chest pain due to reduced blood flow to the heart muscle. They work by dilating blood vessels, which increases blood flow to the heart and decreases the heart's workload.

Isosorbide dinitrate is specifically classified as a nitrate. It acts by relaxing vascular smooth muscle, which leads to vasodilation. This increased vessel diameter reduces the heart's oxygen demand, making it effective for the management of angina episodes. Nitrates such as isosorbide dinitrate can be administered sublingually for immediate relief during angina attacks or as longer-acting formulations for prevention.

In contrast, atenolol, propranolol, and metoprolol are all beta-blockers, which are different classes of medications. While beta-blockers can be beneficial in managing angina by reducing heart rate and the heart's oxygen demand, they do not have the vasodilatory properties associated with nitrates. Therefore, they are not classified as nitrates and serve a distinct purpose in angina treatment compared to isosorbide dinitrate.