Metoprolol is an anti-anginal, anti-hypertensive agent that works by selectively inhibiting the beta1 adrenergic receptor. Some of the brand names are Lopressor, Toprol XL, and Kapspargo Sprinkle. Dosing may vary based on if the formulation is the IR or ER form and by indication. For Angina in adults the IR tartrate form starts at 50 mg po bid with weekly increases to a max of 400 mg/day. There is a black box warning for Ischemic Heart Disease warning that abrupt cessation of therapy may harm patients and if therapy is to be discontinued, the patient should be titrated down over 1-2 weeks. The most common side effect is orthostatic hypotension.