Guidelines for Switching from Propranolol to Metoprolol

Dose Equivalence and Maintenance Ranges

A direct 2 : 1 dose conversion (propranolol : metoprolol) based on beta‑blocking potency is recommended, with close monitoring of heart rate and blood pressure during the switch. [1][2]
Propranolol 80 mg twice daily (total 160 mg/day) is equivalent to metoprolol 100 mg twice daily (total 200 mg/day). [1][3]
Propranolol 40 mg twice daily (total 80 mg/day) is equivalent to metoprolol 50 mg twice daily (total 100 mg/day). [1][2]
Typical maintenance dose ranges for angina and similar cardiovascular indications are propranolol 20–80 mg twice daily versus metoprolol 50–200 mg twice daily. [1][4]3

Discontinue propranolol and start metoprolol at the calculated equivalent dose on the same day. 2
In a monitored environment, administer the first metoprolol dose 15 minutes after the last propranolol dose. [2][5]
When the patient is on extended‑release propranolol, initiate metoprolol at the next scheduled dosing time. [6][7]

For patients previously receiving IV propranolol (0.5–1 mg initial bolus, then 40–80 mg orally every 6–8 h), switch to oral metoprolol 25–50 mg every 6 h for 48 h, then to 100 mg twice daily. [2][5]
When starting IV metoprolol de novo, give 5 mg IV over 1–2 min, repeat every 5 min up to a total of 15 mg, then begin oral metoprolol 25–50 mg every 6 h. [1][2]8

Monitor heart rate and blood pressure closely for the first 24–48 h after the switch. [2][5]
Aim for a resting heart rate of 50–60 beats/min unless limited by adverse effects. [1][4]2
Avoid the transition if systolic blood pressure is < 90 mm Hg or heart rate is < 50 beats/min. [2][3]5
Perform continuous ECG monitoring in patients with conduction abnormalities (PR > 0.24 s, second‑ or third‑degree AV block). [9][8]

Metoprolol is β₁‑selective, whereas propranolol is non‑selective; therefore metoprolol is preferred in patients with chronic obstructive pulmonary disease or reactive airway disease—start with low doses such as 12.5 mg orally. [2][3]5
Metoprolol is also favored in peripheral vascular disease. [6][7]

Neither beta‑blocker should be abruptly stopped without transitioning to the alternative agent. [6][7]

Signs of heart failure or low‑output state contraindicate the switch. 9
High risk for cardiogenic shock (age > 70 yr, systolic BP < 120 mm Hg, heart rate > 110 or < 60 bpm, higher Killip class) warrants extreme caution. 8
Marked first‑degree AV block (PR > 0.24 s) or higher‑grade blocks without a pacemaker are contraindications. 5
Active asthma or severe reactive airway disease contraindicates propranolol; metoprolol is safer. 8
Hypotension (systolic BP < 90 mm Hg) precludes the transition. 2

Begin with the calculated equivalent dose and titrate based on clinical response over 2–3 days. [9][8]
Metoprolol tartrate: start 25–50 mg every 6–12 h, then shift to twice‑daily dosing within 2–3 days. [9][8]
Metoprolol succinate (extended‑release): initiate 50–200 mg once daily. [6][7][10][11]
Maximum recommended dose is metoprolol 200 mg twice daily (total 400 mg/day). [1][6][4][7]

Initiate intravenous metoprolol with a 5 mg bolus administered over 1–2 minutes; repeat the bolus every 5 minutes as needed, not exceeding a total of 15 mg, then transition to oral metoprolol 25–50 mg every 6 hours. [12][13]

Metoprolol’s β₁‑selectivity (versus propranolol’s non‑selectivity) makes it the preferred β‑blocker for patients with chronic obstructive pulmonary disease or reactive airway disease, reducing the risk of bronchospasm. 12

In patients with active asthma or severe reactive airway disease, propranolol is contraindicated; metoprolol is safer but still requires careful monitoring. 12

Clinical guideline statements identify bisoprolol, metoprolol succinate, carvedilol, and nebivolol as the only β‑blockers with proven mortality benefit in heart failure with reduced ejection fraction. [14][15]
The MERIT‑HF trial demonstrated that metoprolol succinate reduced all‑cause mortality by 34 % compared with placebo in patients with chronic heart failure. [14][15]