Metoprolol
Lopressor
Class:
Beta Blocker
Beta Blocker
Mechanism of Action:
Selective inhibitor of beta1-adrenergic receptors; completely blocks beta 1 receptors, with little or no effect on Beta 2 receptors at doses <100 mg.
Selective inhibitor of beta1-adrenergic receptors; completely blocks beta 1 receptors, with little or no effect on Beta 2 receptors at doses <100 mg.
Indications:
- Atrial fibrillation
- Atrial flutter
Contraindications:
- Hypersensitivity to metoprolol or any component of the formulation
- Sinus bradycardia
- Heart block greater than first degree (except in patients with a functioning artificial pacemaker)
- Cardiogenic shock
- Uncompensated cardiac failure
- Pregnancy (2nd and 3rd trimesters)
Adverse reactions:
- Respiratory: Bronchospasm.
- Cardiovascular: Bradycardia, palpitations, edema, congestive heart failure, reduced peripheral circulation.
- Central nervous system: Drowsiness, insomnia.
Drug Interactions
- Drugs with slow AV conduction (digoxin): effects may be additive with beta-blockers.
- Glucagon: Metoprolol may blunt the hypoglycemic action of glucagon.
- Verapamil or Diltiazem may have synergistic or additive pharmacological effects when taken concurrently with beta-blockers; avoid concurrent IV use.
Adult Dosage and Administration
5 mg over 1-2 minutes slow IVP (Medical Control Option). May repeat every 5 minutes to a maximum of 15mg.
5 mg over 1-2 minutes slow IVP (Medical Control Option). May repeat every 5 minutes to a maximum of 15mg.
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Pediatric Dosage and AdministrationNot recommended in pediatric population.
The safety and effectiveness of Metoprolol has not been established in children.
Special Considerations:
- Pregnancy safety (manufacturer): Category C
- Pregnancy safety (expert analysis): Category D (2nd and 3rd trimesters)