Calcium Channel Blockers: Because of significant inotropic and chronotropic effects in patients treated with beta-blockers and calcium channel blockers of the verapamil and diltiazem type, caution should be exercised in patients treated with these agents concomitantly.

Peripheral Vascular Disease: Can aggravate symptoms of arterial insufficiency.

Anaphylactic Reactions: Patients may be unresponsive to the usual doses of epinephrine used to treat allergic reaction.

Thyrotoxicosis: Abrupt withdrawal in patients with thyrotoxicosis might precipitate a thyroid storm.

Diabetes and Hypoglycemia: May mask tachycardia occurring with hypoglycemia.

Do not routinely withdraw chronic beta blocker therapy prior to surgery.

Major Surgery: Avoid initiation of high-dose extended-release metoprolol in patients undergoing non-cardiac surgery because it has been associated with bradycardia, hypotension, stroke and death.

Pheochromocytoma: If required, first initiate therapy with an alpha blocker.

Bronchospastic Disease: Avoid beta blockers.

Heart Failure: Worsening cardiac failure may occur.

Half life of metoprolol