Ischemic Heart Disease: Exacerbations of angina pectoris, and in some cases, myocardial infarction have occurred after abrupt discontinuation of certain beta-blockers. Gradually reduce dosage over a period of 1 to 2 weeks and carefully monitor the patient when discontinuing chronically administered metoprolol, particularly in patients with ischemic heart disease. Metoprolol should promptly be reinstated, at least temporarily, and initiate other measures appropriate for the management of unstable angina if angina markedly worsens or acute coronary insufficiency develops. Patients should be warned against interruption or discontinuation of therapy without physician's advice. It may be prudent not to discontinue metoprolol abruptly even in patients treated only for hypertension since coronary artery disease is common and may be unrecognized.