Metoprolol succinate
Metoprolol succinate
Metoprolol
(me-toe- PROH-lohl)
Pregnancy Category: C Toprol XL (Rx)
Metoprolol tartrate
Metoprolol tartrate (Lopressor)
Metoprolol
(me-toe- PROH-lohl)
Pregnancy Category: B Apo-Metoprolol Apo-Metoprolol (Type L) Betaloc Betaloc Durules Gen-Metoprolol Lopressor Novo-Metoprol Nu-Metop PMS-Metoprolol-B (Rx)

Classification: Beta-adrenergic blocking agent

See Also: See also Beta-Adrenergic Blocking Agents .

Action/Kinetics: Exerts mainly beta-1-adrenergic blocking activity although beta-2 receptors are blocked at high doses. Has no membrane stabilizing or intrinsic sympathomimetic effects. Moderate lipid solubility. Onset: 15 min. Peak plasma levels: 90 min. t 1/2: 3-7 hr. Effect of drug is cumulative. Food increases bioavailability. Exhibits significant first-pass effect. Metabolized in liver and excreted in urine.

Uses: Metoprolol Succinate: Alone or with other drugs to treat hypertension. Chronic management of angina pectoris.
Metoprolol Tartrate: Hypertension (either alone or with other antihypertensive agents, such as thiazide diuretics). Acute MI in hemodynamically stable clients. Angina pectoris. Investigational: IV to suppress atrial ectopy in COPD, aggressive behavior, prophylaxis of migraine, ventricular arrhythmias, enhancement of cognitive performance in geriatric clients, essential tremors.

Additional Contraindications: Myocardial infarction in clients with a HR of less than 45 beats/min, in second- or third-degree heart block, or if SBP is less than 100 mm Hg. Moderate to severe cardiac failure.

Special Concerns: Safety and effectiveness have not been established in children. Use with caution in impaired hepatic function and during lactation.

Laboratory Test Alterations: Serum transaminase, LDH, alkaline phosphatase.

Additional Drug Interactions: Cimetidine / May plasma metoprolol levels Contraceptives, oral / May metoprolol effects Methimazole / May metoprolol effects Phenobarbital / Metoprolol effect R/T liver metabolism Propylthiouracil / May metoprolol effects Quinidine / May metoprolol effects Rifampin / Metoprolol effect R/T liver metabolism

How Supplied: Metoprolol succinate: Tablet, Extended Release: 50 mg, 100 mg, 200 mg. Metoprolol tartrate: Injection: 1 mg/mL; Tablet: 50 mg, 100 mg

Dosage
?Metoprolol Succinate Tablets Angina pectoris.
Individualized. Initial: 100 mg/day in a single dose. Dose may be increased slowly, at weekly intervals, until optimum effect is reached or there is a pronounced slowing of HR. Doses above 400 mg/day have not been studied.
Hypertension.
Initial: 50-100 mg/day in a single dose with or without a diuretic. Dosage may be increased in weekly intervals until maximum effect is reached. Doses above 400 mg/day have not been studied.
?Metoprolol Tartrate Tablets Hypertension.
Initial: 100 mg/day in single or divided doses; then, dose may be increased weekly to maintenance level of 100-450 mg/day. A diuretic may also be used.
Aggressive behavior.
200-300 mg/day.
Essential tremors.
50-300 mg/day.
Prophylaxis of migraine.
50-100 mg b.i.d.
Ventricular arrhythmias.
200 mg/day.
?Metoprolol Tartrate Injection (IV) and Tablets Early treatment of MI.
3 IV bolus injections of 5 mg each at approximately 2-min intervals. If clients tolerate the full IV dose, give 50 mg q 6 hr PO beginning 15 min after the last IV dose (or as soon as client's condition allows). This dose is continued for 48 hr followed by late treatment: 100 mg b.i.d. as soon as feasible; continue for 1-3 months (although data suggest treatment should be continued for 1-3 years). In clients who do not tolerate the full IV dose, begin with 25-50 mg q 6 hr PO beginning 15 min after the last IV dose or as soon as the condition allows.