From the Guidelines
Metoprolol succinate is the preferred formulation for long-term management of hypertension, heart failure, and stable angina due to its extended-release mechanism and once-daily dosing, which provides steady blood levels and improves patient adherence. The difference between metoprolol succinate and tartrate lies in their release mechanisms and dosing schedules. Metoprolol succinate is an extended-release formulation, taken once daily, providing steady blood levels over 24 hours, making it suitable for conditions requiring consistent beta-blockade, such as hypertension, heart failure, and stable angina 1. In contrast, metoprolol tartrate is immediate-release, typically taken twice daily, and is often used in acute situations like myocardial infarction or when rapid onset is needed. Key points to consider when choosing between metoprolol succinate and tartrate include:
- The specific condition being treated: Metoprolol succinate is preferred for long-term management of hypertension, heart failure, and stable angina, while metoprolol tartrate may be used in acute situations.
- Patient adherence factors: Once-daily dosing of metoprolol succinate may improve patient adherence compared to twice-daily dosing of metoprolol tartrate.
- Desired pharmacokinetic profile: Metoprolol succinate provides steady blood levels over 24 hours, while metoprolol tartrate has a more rapid onset of action. The 2013 ACCF/AHA guideline for the management of heart failure recommends the use of metoprolol succinate, along with other beta blockers, to reduce morbidity and mortality in patients with heart failure with reduced ejection fraction (HFrEF) 1. Additionally, 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 lists metoprolol succinate as a preferred agent for the treatment of hypertension, particularly in patients with HFrEF 1. In terms of clinical significance, metoprolol succinate has been shown to reduce mortality in patients with heart failure, as demonstrated in the Metoprolol CR/XL Randomized Intervention Trial in Heart Failure (MERIT-HF) trial, which was stopped prematurely due to a 34% reduction in mortality in the metoprolol arm 1. Overall, metoprolol succinate is the preferred formulation for long-term management of hypertension, heart failure, and stable angina due to its extended-release mechanism, once-daily dosing, and established benefits in reducing morbidity and mortality.
From the Research
Clinical Significance of Metoprolol Succinate vs Tartrate
- Metoprolol succinate is a controlled-release/extended-release formulation designed to provide relatively constant metoprolol plasma concentrations and beta(1)-blockade while retaining the convenience of once daily administration 2.
- A 100-mg metoprolol controlled/extended-release tablet contains 95 mg of metoprolol succinate and is considered to have equivalent activity of 100 mg metoprolol tartrate 2.
- Metoprolol succinate has been shown to reduce mortality and hospitalizations in patients with heart failure and a history of hypertension 3.
- The extended-release formulation of metoprolol succinate provides consistent beta(1)-blockade over the 24-hour dosing interval, with less fluctuation in metoprolol plasma concentrations compared to immediate-release metoprolol 4.
Pharmacokinetic and Pharmacodynamic Properties
- Metoprolol succinate is designed to produce even and consistent beta(1)-blockade throughout the 24-hour dosing interval 4.
- The tablet disintegrates into individual pellets, each acting as a diffusion cell releasing the drug at a relatively constant rate over a period of approximately 20 hours 2.
- Metoprolol succinate has been shown to reduce the relative risk of all-cause mortality by 34% versus placebo in patients with chronic heart failure 4.
Therapeutic Efficacy
- Metoprolol succinate is effective in reducing cardiovascular events and mortality in patients with hypertension and coronary heart disease 2.
- Metoprolol succinate has been shown to reduce the total number of hospitalizations for worsening heart failure by 30% compared to placebo 3.
- Metoprolol succinate is well tolerated, with a similar proportion of patients discontinuing therapy due to adverse events relative to placebo 4.
Comparison with Metoprolol Tartrate
- Metoprolol tartrate is an immediate-release formulation that requires twice daily administration 5.
- Metoprolol succinate has been shown to provide consistent beta(1)-blockade over the 24-hour dosing interval, whereas metoprolol tartrate may have more fluctuation in metoprolol plasma concentrations 4.
- Metoprolol succinate is considered to have equivalent activity to metoprolol tartrate, but with the convenience of once daily administration 2.