Metoprolol (Lopressor)

Question 1

Metoprolol Classification

Answer 1

Beta-Blocker

Question 2

Metoprolol Mechanism

Answer 2

B1R antagonist -> inhibits extracellular Ca2+ entry and Ca2+ release from sarcoplasmic reticulum in cardiac cells -> negative inotropy, chronotropy, dromotropy

Question 3

Metoprolol Pharmacokinetics

Answer 3

Onset: Immediate
Peak Effects: 20min
Duration: 13-19h
Half Life: 3-4h

Question 4

Metoprolol Indications

Answer 4

• Rapid Ventricular rates (>150bpm) associated with A-fib, A-flutter
• PSVT refractory to adenosine

Question 5

Metoprolol Contraindications

Answer 5

• Hypotension

- Decompensated cardiogenic shock

Question 6

Metoprolol Side effects/adverse reactions

Answer 6

Bradycardia, hypotension, dyspnea, lethargy, wheezing, dizziness

Question 7

Metoprolol Dose

Answer 7

Adult:
5mg slow IV IO q5min, max total dose = 15mg
Pedi:
Not for Pediatrics

Question 8

Metoprolol Precautions

Answer 8

May exacerbate asthma, COPD, bronchospasm, or CHF

Question 9

Metoprolol Drug Interactions

Answer 9

• Adverse side effects with digoxin

- Do NOT give to pts receiving IV Ca2+ channel blockers; will increase risk of profound bradycardia