Metoprolol Blood Pressure Parameters
For hypertension management, initiate metoprolol tartrate at 25-50 mg twice daily or metoprolol succinate extended-release at 50 mg once daily, titrating every 1-2 weeks to a maximum of 200 mg daily for tartrate or 400 mg daily for succinate, with a target blood pressure reduction of at least 20/10 mmHg, ideally to <140/90 mmHg. 1
Initial Dosing Strategy
Metoprolol tartrate (immediate-release):
- Start at 25-50 mg orally twice daily 1
- Maximum daily dose: 200 mg 1
- Suitable for twice-daily administration despite shorter half-life 2
Metoprolol succinate (extended-release):
- Start at 50 mg once daily 1
- Maximum daily dose: 400 mg 1
- Provides more consistent 24-hour blood pressure control 3, 4
Titration Protocol
- Increase dose gradually every 1-2 weeks if blood pressure control is not achieved 1
- Target blood pressure reduction: at least 20/10 mmHg 1
- Goal blood pressure: <140/90 mmHg (or <130/80 mmHg for most adults per recent guidelines) 1, 5
- In elderly patients (60-75 years), 100 mg once daily achieved satisfactory response in 50% at 4 weeks and 65% at 8 weeks 6
Monitoring Parameters
At each visit, assess:
- Blood pressure and heart rate 1
- Signs of worsening heart failure (increased dyspnea, weight gain, peripheral edema) 1
- Bronchospasm, particularly during initiation 1
- Target resting heart rate: 50-60 beats per minute unless limiting side effects occur 7
Critical Contraindications
Absolute contraindications include: 1
- Signs of heart failure or low output state
- Increased risk for cardiogenic shock
- PR interval >0.24 seconds
- Second or third-degree heart block
- Active asthma or reactive airways disease
Risk factors for cardiogenic shock: 7
- Systolic BP <120 mmHg
- Sinus tachycardia >110 bpm or heart rate <60 bpm
- Age >70 years
- Increased time since symptom onset
Important Clinical Considerations
Beta-blockers are NOT first-line agents for hypertension unless the patient has ischemic heart disease or heart failure 1, 5. Preferred first-line treatments are ACE inhibitors, ARBs, dihydropyridine calcium channel blockers, and thiazide/thiazide-like diuretics 5.
Combination therapy considerations:
- If monotherapy with metoprolol is insufficient, adding 12.5-25 mg hydrochlorothiazide is effective 6, 8
- This combination approach achieved satisfactory control in 83% of patients by 12 weeks 3
Hypertensive Emergency Dosing
For acute severe hypertension requiring IV administration: 5
- Dose: 2.5-5 mg IV bolus over 2 minutes
- May repeat every 5 minutes to maximum dose of 15 mg
- Onset of action: 1-2 minutes
- Duration of action: 5-8 hours
- Note: Labetalol is preferred over metoprolol for hypertensive emergencies 5
Common Pitfalls to Avoid
- Never abruptly discontinue metoprolol to prevent rebound hypertension or worsening angina 7, 1
- Do not use metoprolol tartrate (immediate-release) for heart failure—only metoprolol succinate extended-release has proven mortality benefit 7, 9
- Avoid IV metoprolol in patients with decompensated heart failure, as it increases cardiogenic shock risk 7
- Monitor for hypokalemia and hyperuricemia when combining with hydrochlorothiazide 6
Pharmacokinetic Considerations
- Oral bioavailability: approximately 50% due to first-pass metabolism 10
- Elimination half-life: 3-4 hours (7-9 hours in poor CYP2D6 metabolizers) 10
- Poor CYP2D6 metabolizers (8% of Caucasians) exhibit several-fold higher plasma concentrations 10
- No dose adjustment needed for renal impairment 10
- Hepatic impairment may prolong half-life up to 7.2 hours 10