From the Guidelines
The recommended dosage of metoprolol for treating adult hypertension is 100-200 mg per day, with a starting dose of 25-50 mg twice daily of the immediate-release formulation or 50-100 mg once daily of the extended-release formulation, as stated in 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 1.
Key Considerations
- The dose can be gradually increased at weekly intervals based on blood pressure response.
- The maximum recommended daily dose is 400 mg, though most patients achieve adequate blood pressure control with lower doses.
- Metoprolol should be taken consistently, preferably at the same time each day, and patients should not stop taking it abruptly as this can cause rebound hypertension or worsen underlying heart conditions.
Mechanism of Action and Side Effects
- Metoprolol works by blocking beta-1 adrenergic receptors primarily in the heart, reducing heart rate and cardiac output, which leads to lower blood pressure.
- Side effects may include fatigue, dizziness, and bradycardia, so dose adjustments may be needed for patients with kidney or liver impairment, the elderly, or those with certain comorbidities.
Monitoring and Adjustments
- It's essential to monitor blood pressure regularly while adjusting the dose.
- Patients with certain conditions, such as heart failure or ischemic heart disease, may require closer monitoring and dose adjustments.
- The guideline recommends avoiding abrupt cessation of metoprolol, as this can cause rebound hypertension or worsen underlying heart conditions 1.
From the FDA Drug Label
In a large (1,395 patients randomized), double-blind, placebo-controlled clinical study, metoprolol was shown to reduce 3-month mortality by 36% in patients with suspected or definite myocardial infarction Patients were randomized and treated as soon as possible after their arrival in the hospital, once their clinical condition had stabilized and their hemodynamic status had been carefully evaluated. Initial treatment consisted of intravenous followed by oral administration of metoprolol or placebo, given in a coronary care or comparable unit.
The recommended dosage of metoprolol for treating adult hypertension is not explicitly stated in the provided drug label for IV administration. However, for hypertension, metoprolol has been shown to be an effective antihypertensive agent when used alone or as concomitant therapy with thiazide-type diuretics, at oral dosages of 100 to 450 mg daily 2. For IV administration in myocardial infarction, the label mentions that patients received intravenous metoprolol, but it does not specify the exact dosage. Key points:
- The label does not provide a specific IV dosage for hypertension.
- Oral dosages for hypertension range from 100 to 450 mg daily.
- The IV dosage for myocardial infarction is not specified in the label.
From the Research
Metoprolol IV Adult Hypertension Dosage
- The recommended dosage of metoprolol for treating adult hypertension is not explicitly stated in the provided studies, but we can look at the dosages used in certain scenarios:
- In a case report 3, a 12-year-old female with severe hypertension was administered intravenous Metoprolol 2.5 mg three times with 5 minutes interval between doses.
- However, this dosage may not be directly applicable to adults, and the studies do not provide a clear recommendation for adult hypertension dosage.
Available Information on Metoprolol
- Metoprolol is a selective beta(1)-adrenergic antagonist extensively used since 1975, and it has proven its efficacy in reducing cardiovascular events and mortality in patients with hypertension and coronary heart disease 4.
- A controlled release/extended-release formulation of metoprolol succinate was designed to provide relatively constant metoprolol plasma concentrations and beta(1)-blockade while retaining the convenience of once daily administration 4.
Treatment of Hypertensive Crises
- Hypertensive crises are further defined as either hypertensive emergencies or urgencies, depending on the degree of blood pressure elevation and presence of end-organ damage 5.
- Immediate reduction in blood pressure is required only in patients with acute end-organ damage (i.e., hypertensive emergency) and requires treatment with a titratable, short-acting, intravenous antihypertensive agent 5.
- Rapid-acting intravenous antihypertensive agents are available, including labetalol, esmolol, fenoldopam, nicardipine, and sodium nitroprusside 5.
Blood Pressure Response to Antihypertensives
- A study found that among commonly used antihypertensives, IV hydralazine resulted in the most significant drop in BP following severe HTN, while metoprolol and amlodipine did not lower BP 6.