From the Guidelines
The half-life of metoprolol is approximately 3-7 hours for metoprolol succinate and 3-4 hours for metoprolol tartrate. This information is based on the most recent guideline evidence from the 2023 ACC/AHA/ACCP/HRS guideline for the diagnosis and management of atrial fibrillation, published in Circulation in 2024 1. The half-life of metoprolol can vary depending on the formulation, with metoprolol succinate having a slightly longer half-life compared to metoprolol tartrate.
Key Points
- The elimination half-life of metoprolol tartrate is 3-4 hours, as indicated in the guideline evidence 1.
- The elimination half-life of metoprolol succinate is 3-7 hours, allowing for more flexible dosing schedules 1.
- Understanding the half-life of metoprolol is crucial for determining the appropriate dosing schedule and anticipating the duration of its beta-blocking effects.
- Factors such as liver dysfunction or heart failure may prolong the elimination half-life of metoprolol, necessitating adjustments in dosing schedules.
- Genetic variations in the CYP2D6 enzyme pathway, which metabolizes metoprolol, can also affect the drug's half-life and should be considered in clinical practice 1.
From the FDA Drug Label
Elimination of metoprolol is mainly by biotransformation in the liver The mean elimination half-life of metoprolol is 3 to 4 hours; in poor CYP2D6 metabolizers the half-life may be 7 to 9 hours. The half-life of metoprolol is 3 to 4 hours in most subjects, but it may be 7 to 9 hours in poor CYP2D6 metabolizers 2.
From the Research
Half-Life of Metoprolol
- The half-life of metoprolol is not explicitly stated in the provided studies 3, 4, 5, 6.
- However, it is mentioned that metoprolol has a duration of effect that is longer than expected from its half-life, making it suitable for twice daily administration 3.
- The studies primarily focus on the pharmacological properties, therapeutic efficacy, and clinical uses of metoprolol, rather than its pharmacokinetic properties such as half-life.
- A study on propranolol, a different beta-blocker, mentions that the half-life of propranolol varies from 1.5-3 hours among individuals 7, but this information is not directly applicable to metoprolol.
- Overall, there is limited information available on the half-life of metoprolol in the provided studies.