Drug Card: Metoprolol

Medication Name: Metoprolol

  • Generic Name: Metoprolol

  • Trade Name(s): Lopressor, Toprol-XL

Drug Classification: Beta-blocker

Description:
Metoprolol is used to manage hypertension, angina, and heart failure. It reduces the heart rate and myocardial contractility.

Mechanism of Action:
Metoprolol selectively blocks beta-1 adrenergic receptors, leading to decreased heart rate, contractility, and conduction velocity through the AV node.

Pharmacokinetics:

  • Absorption: Rapidly absorbed; oral bioavailability is about 50%.

  • Distribution: Widely distributed; crosses the blood-brain barrier.

  • Metabolism: Metabolized primarily by the liver (CYP2D6).

  • Excretion: Excreted in urine; half-life is about 3-7 hours.

Indications/Field Use:

  • Hypertension

  • Acute coronary syndrome (ACS)

  • Atrial fibrillation

Contraindications:

  • Severe bradycardia

  • Heart block

  • Hypersensitivity to metoprolol

Side Effects/Adverse Reactions:

  • Bradycardia

  • Hypotension

  • Fatigue

  • Dizziness

Dose:

  • Hypertension: 25-100 mg orally daily, adjusted as needed.

  • IV Dose for ACS: 5 mg IV every 5 minutes (max 15 mg).

Precautions:

  • Monitor heart rate and blood pressure regularly.

  • Avoid abrupt withdrawal to prevent rebound hypertension.

Drug-Drug Interactions:

  • May enhance the effects of other antihypertensives.

  • Use caution with other beta-blockers.