What is the effect of Metoprolol (beta blocker) on Blood Pressure (BP)?

From the Guidelines

Metoprolol is effective in lowering blood pressure, with an expected reduction of approximately 9/5 mmHg with office BP and 5/3 mmHg with ABPM, as shown in the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1.

Key Points

• Metoprolol works by blocking beta-1 adrenergic receptors in the heart, reducing heart rate and cardiac output.
• The full antihypertensive effect of metoprolol usually develops within 1-2 weeks of consistent use.
• Metoprolol is particularly beneficial for hypertensive patients with concurrent conditions like angina, heart failure, or post-myocardial infarction.
• Side effects may include fatigue, dizziness, and bradycardia.
• Blood pressure should be monitored regularly during treatment, and the medication should be taken consistently at the same time each day.
• Abrupt discontinuation should be avoided as it can cause rebound hypertension; instead, the dose should be gradually tapered over 1-2 weeks if discontinuation is necessary.

Dosage and Administration

• Therapeutic doses of metoprolol are typically 25-100 mg twice daily for immediate release or 50-200 mg once daily for extended release.
• The medication can be combined with lifestyle modifications such as reduced sodium intake, regular exercise, and weight management for optimal effect.

Clinical Considerations

• The 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults recommends metoprolol as a first-line therapy in the treatment of hypertension when it occurs in patients with stable ischemic heart disease (SIHD) 1.
• The 2024 ESC guidelines suggest that beta-blockers, including metoprolol, are not considered first-line BP-lowering medications outside of compelling indications, due to inferior efficacy in reducing cardiovascular disease events, particularly stroke, among patients with hypertension 1.

From the FDA Drug Label

CLINICAL PHARMACOLOGY Mechanism of Action Metoprolol is a beta 1-selective (cardioselective) adrenergic receptor blocker. Clinical pharmacology studies have demonstrated the beta-blocking activity of metoprolol, as shown by (1) reduction in heart rate and cardiac output at rest and upon exercise, (2) reduction of systolic blood pressure upon exercise, Hypertension The mechanism of the antihypertensive effects of beta-blocking agents has not been fully elucidated However, several possible mechanisms have been proposed: (1) competitive antagonism of catecholamines at peripheral (especially cardiac) adrenergic neuron sites, leading to decreased cardiac output; In several studies of patients with acute myocardial infarction, intravenous followed by oral administration of metoprolol caused a reduction in heart rate, systolic blood pressure and cardiac output

Metoprolol's effect on blood pressure (BP) is to reduce it, as demonstrated by:

• Reduction of systolic blood pressure upon exercise
• Reduction of systolic blood pressure in patients with acute myocardial infarction The exact mechanism is not fully understood, but possible mechanisms include:
• Competitive antagonism of catecholamines at peripheral adrenergic neuron sites, leading to decreased cardiac output 2

From the Research

Metoprolol Effect on Blood Pressure

• Metoprolol is a beta-blocker that has been widely used in the treatment of mild to moderate hypertension and angina pectoris 3.
• The drug has been shown to be at least as effective as other beta-blockers, diuretics, and certain calcium antagonists in the majority of patients 3.
• Optimum treatment of hypertension with metoprolol is achieved through dose titration within the therapeutic range, and satisfactory control can be maintained in many patients with single daily doses of conventional or slow release formulations 3.
• Addition of a diuretic may improve the overall response rate in hypertension, as seen in a study where 25 mg of hydrochlorothiazide was added to metoprolol therapy in patients who did not achieve adequate blood pressure control after 4 weeks 4.

Efficacy and Safety of Metoprolol

• A prospective, open-label surveillance study of 21,692 patients with mild-to-moderate hypertension between the ages of 50 to 75 years found that metoprolol administered as monotherapy or in combination with hydrochlorothiazide was effective in normalizing blood pressure in a majority of elderly hypertensive patients 4.
• The study also found that both drug regimens were well tolerated, with less than a 5% incidence of medical problems and excellent or good tolerability noted for 94% of the patients 4.
• Metoprolol has been shown to be generally well tolerated, with temporary fatigue, dizziness, and headache being among the most frequently reported side effects 3.

Combination Therapy with Metoprolol

• Combination antihypertensive therapy, including beta-blockers and diuretics, is an important option that combines efficacy of blood pressure reduction and a low side effect profile with convenient once-daily dosing to enhance compliance 5.
• The combination of beta-blockers, such as metoprolol, and ACE inhibitors is of special interest due to their complementary actions on the sympathetic nervous system and renin-angiotensin-aldosterone system, two interlinked pathways that influence cardiovascular risk and disease outcomes 6.
• Combining these established antihypertensive agents into a single pill continues to provide effective blood pressure lowering and improved cardiovascular outcomes while allowing a greater proportion of patients to rapidly achieve treatment targets 6.