From the Guidelines
Carvedilol is preferred over metoprolol tartrate due to its additional alpha-blocking properties and potential for better outcomes in heart failure, as demonstrated by a 17% greater mortality reduction in the Carvedilol or Metoprolol European Trial (COMET) 1. Metoprolol tartrate and carvedilol are both beta-blockers used to treat cardiovascular conditions, but they have important differences. Metoprolol is a selective beta-1 blocker, primarily affecting the heart without significantly impacting the lungs or blood vessels. It's typically dosed twice daily (25-100 mg per dose) for conditions like hypertension, angina, and heart failure. Carvedilol, in contrast, is a non-selective beta-blocker that blocks both beta-1 and beta-2 receptors, plus it has alpha-blocking properties. This gives carvedilol additional vasodilating effects, making it particularly useful for heart failure patients. Some key points to consider when choosing between metoprolol tartrate and carvedilol include:
- Carvedilol's non-selective nature means it should be used cautiously in patients with asthma or COPD, where metoprolol might be safer.
- Carvedilol may provide better outcomes in heart failure and cause fewer metabolic side effects like increased blood sugar or cholesterol.
- Both medications require gradual dose adjustments and should never be stopped abruptly due to potential rebound effects that could trigger chest pain or heart attacks, as supported by guidelines from the American College of Cardiology Foundation/American Heart Association 1. The American Heart Association, American College of Cardiology, and American Society of Hypertension also recommend the use of beta-blockers, including carvedilol, metoprolol succinate, bisoprolol, or nebivolol, for the long-term management of patients with hypertension-related left ventricular systolic dysfunction 1. Overall, the choice between metoprolol tartrate and carvedilol should be based on individual patient characteristics and medical history, with carvedilol being a preferred option for patients with heart failure due to its potential for better outcomes.
From the FDA Drug Label
β-adrenoreceptor blocking activity has been demonstrated in animal and human studies showing that carvedilol (1) reduces cardiac output in normal subjects; (2) reduces exercise and/or isoproterenol-induced tachycardia; and (3) reduces reflex orthostatic tachycardia. Metoprolol tartrate is (±)-1-(Isopropylamino)-3-[ p-(2-methoxyethyl)phenoxy]-2-propanol L-(+)-tartrate (2:1) salt, and its structural formula is:
The main difference between Metoprolol tartrate and Carvedilol is that:
- Carvedilol has both β-adrenoreceptor blocking activity and α1-adrenoreceptor blocking activity, which contributes to its ability to lower blood pressure and reduce peripheral vascular resistance.
- Metoprolol tartrate is a selective beta 1-adrenoreceptor blocking agent, which means it primarily affects the heart rate and cardiac output. Key differences include:
- Mechanism of action: Carvedilol has a dual mechanism of action, while Metoprolol tartrate has a more selective mechanism.
- Effects on blood pressure: Carvedilol lowers blood pressure more in the standing position due to its α1-adrenoreceptor blocking activity, while Metoprolol tartrate may not have this effect to the same extent. 2 3
From the Research
Differences between Metoprolol Tartrate and Carvedilol
- Metoprolol tartrate and carvedilol are both beta-blockers used to treat heart failure, but they have distinct differences in terms of their pharmacokinetic and pharmacodynamic properties 4.
- Carvedilol is a non-selective beta-blocker with alpha-1 receptor antagonist activity and antioxidant properties, whereas metoprolol tartrate is a selective beta-blocker 5.
- A study comparing carvedilol and metoprolol tartrate found that carvedilol reduced all-cause mortality by 17% compared to metoprolol tartrate in patients with chronic heart failure 6.
- Another study found that carvedilol had a greater effect on sitting and standing blood pressure, left ventricular end-diastolic dimension, and mitral E wave deceleration time compared to metoprolol 5.
- Metoprolol tartrate is a short-acting form of metoprolol, whereas metoprolol succinate is a longer-acting salt and is designed as a once-daily formulation 4.
- The dosing of metoprolol tartrate in the COMET trial may have been inadequate based on prior studies, and additional studies are needed to compare carvedilol directly to metoprolol succinate 4.
- Endothelial function was found to be unaffected by changing between carvedilol and metoprolol tartrate or metoprolol succinate in patients with heart failure 7.
- The choice of beta-blocker is important, as benefit is not a class-effect, and carvedilol, metoprolol succinate, and bisoprolol are considered to be the most effective options for treating heart failure 8.
Pharmacokinetic and Pharmacodynamic Properties
- Carvedilol is an inherently long-acting beta-blocker, whereas the duration of beta blockade for metoprolol is dependent on the salt and formulation used 4.
- Metoprolol tartrate has a shorter half-life compared to metoprolol succinate, which is a longer-acting salt 4.
- Carvedilol has antioxidant properties, which may contribute to its beneficial effects in heart failure 5.
- The pharmacodynamic differences between carvedilol and metoprolol tartrate may give rise to differences in duration of beta blockade and potential drug interactions 4.
Clinical Implications
- The choice of beta-blocker should be based on individual patient characteristics and the specific formulation used 8.
- Carvedilol and metoprolol succinate are considered to be the most effective options for treating heart failure, but additional studies are needed to compare their effects directly 4.
- The dosing of metoprolol tartrate should be optimized based on prior studies to ensure adequate beta blockade 4.
- Endothelial function is unaffected by changing between carvedilol and metoprolol tartrate or metoprolol succinate, but further studies are needed to confirm these findings 7.