Why is metoprolol (beta-blocker) preferred over atenolol (beta-blocker) for hypertension treatment?

Metoprolol vs. Atenolol for Hypertension Treatment

Metoprolol is preferred over atenolol for hypertension treatment primarily because recent clinical trial analyses have questioned atenolol's relative cardiovascular benefit in hypertension patients. 1

Pharmacological Differences

• Both metoprolol and atenolol are beta-1 selective (cardioselective) adrenoceptor blockers without intrinsic sympathomimetic activity 1
• Metoprolol is available in immediate-release (twice daily dosing) and sustained-release formulations (once daily dosing) 1
• Atenolol is primarily eliminated unchanged through the kidneys, requiring dose adjustment in patients with moderate to severe renal impairment (GFR <30 ml/min) 2
• Metoprolol undergoes hepatic metabolism, making it preferable in patients with renal dysfunction 3

Cardiovascular Outcomes

• In patients with hypertension, the relative cardiovascular benefit of atenolol has been questioned based on recent clinical trial analyses 1
• Metoprolol succinate (extended-release) is preferred in patients with heart failure with reduced ejection fraction (HFrEF) 1
• One study suggested greater benefit with carvedilol (mixed beta-blocking and alpha-adrenergic-blocking effects) than metoprolol (relatively selective beta-1 blocker) in heart failure patients 1

Dosing Considerations

• Metoprolol tartrate: 100-200 mg twice daily for hypertension 1
• Metoprolol succinate: 50-200 mg once daily for hypertension 1
• Atenolol: 25-100 mg twice daily for hypertension 1
• Both drugs can be administered once daily for hypertension, but evidence for effective control with once-daily regimen is more convincing with atenolol 2, 4
• However, some studies suggest that metoprolol slow-release formulation can be as effective as atenolol in once-daily dosing 4

Special Populations

• Both metoprolol and atenolol are cardioselective beta blockers, making them preferred in patients with bronchospastic airway disease requiring beta-blocker therapy 1
• In patients with significant chronic obstructive pulmonary disease who may have reactive airway disease, start with low doses of a beta-1-selective agent like metoprolol 1
• For patients with concerns about beta-blocker intolerance, metoprolol is preferred as a short-acting beta-1-specific drug 1
• In mild wheezing or history of chronic obstructive pulmonary disease, a short-acting cardioselective agent at reduced dose (e.g., 12.5 mg of metoprolol) is recommended rather than complete avoidance 1

Clinical Decision Making

1. For most hypertension patients: Choose metoprolol over atenolol due to questioned cardiovascular benefits of atenolol 1
2. For patients with renal impairment: Prefer metoprolol over atenolol 2
3. For patients with HFrEF: Metoprolol succinate is specifically preferred 1
4. For patients requiring once-daily dosing: Either metoprolol succinate or atenolol can be effective, though some evidence suggests atenolol may provide more consistent 24-hour control 2, 4

Common Pitfalls

• Abrupt cessation of either beta-blocker should be avoided to prevent rebound hypertension or other adverse effects 1
• Beta blockers are not recommended as first-line agents for hypertension unless the patient has ischemic heart disease or heart failure 1
• Dose titration is important for both medications to achieve optimal blood pressure control 3
• When using metoprolol in patients with reactive airway disease, start with a low dose (e.g., 12.5 mg) and monitor closely 1