Can metoprolol be given once a day (OAD)?

Metoprolol Can Be Given Once Daily as the Succinate Formulation

Metoprolol succinate (extended-release) can be given once daily (OAD), while metoprolol tartrate requires twice daily dosing. 1, 2

Metoprolol Formulations and Dosing

• Metoprolol comes in two main formulations with different dosing requirements:

  • Metoprolol succinate: Extended-release (ER) formulation designed for once-daily dosing 1
  • Metoprolol tartrate: Immediate-release formulation requiring twice-daily dosing 3

• The extended-release formulation (succinate) maintains consistent plasma concentrations over 24 hours, allowing for once-daily administration 4

• For heart failure patients, metoprolol succinate is typically started at 12.5-25 mg once daily and titrated to a target dose of 200 mg once daily 1, 3

Evidence Supporting Once-Daily Dosing

• According to the American College of Cardiology/American Heart Association guidelines, metoprolol succinate sustained release is administered at 200 mg once daily for heart failure with reduced ejection fraction 3

• The extended-release formulation (CR/ZOK and OROS) was specifically designed to overcome drug delivery problems of earlier formulations by releasing the drug at a relatively constant rate over a 24-hour period 4

• Clinical studies have demonstrated that metoprolol succinate extended-release maintains effective plasma concentrations within a therapeutic range over a 24-hour dose interval 4

• A study comparing extended-release metoprolol (once daily) with immediate-release metoprolol (twice daily) in post-myocardial infarction patients showed similar risk reduction of death over 5 years, supporting the efficacy of once-daily dosing 5

Clinical Applications

• For hypertension management:

  • Metoprolol succinate can be administered once daily at doses ranging from 50-400 mg 1
  • The extended-release formulation provides clinically significant blood pressure reduction for a full 24 hours after administration 4

• For heart failure treatment:

  • The target dose is 200 mg once daily of metoprolol succinate 3, 1
  • Dose should be doubled every 1-2 weeks if well tolerated until reaching target dose 1

• For post-myocardial infarction:

  • After initial IV therapy, oral metoprolol can be transitioned to once-daily dosing using the succinate formulation 1, 2

Important Considerations

• Immediate-release metoprolol tartrate should not be substituted for extended-release metoprolol succinate for once-daily dosing, as studies have shown waning antihypertensive effect at 24 hours with immediate-release formulations 6

• Extended-release metoprolol formulations have demonstrated less pronounced beta-2 mediated bronchoconstrictor effects and less general fatigue compared to some other beta-blockers, likely due to maintaining more consistent plasma levels 4

• Patients with renal failure generally do not require dose adjustments of metoprolol succinate, as the drug is primarily eliminated by hepatic metabolism 2

• Patients with hepatic impairment may require lower doses due to prolonged elimination half-life (up to 7.2 hours) 2

• Poor CYP2D6 metabolizers (approximately 8% of Caucasians) may have higher plasma concentrations and longer half-lives (7-9 hours) 2

Conclusion

When prescribing metoprolol for once-daily dosing, specifically use metoprolol succinate (extended-release) formulation, not metoprolol tartrate. The extended-release formulation provides consistent 24-hour coverage and has been proven effective in clinical trials for various cardiovascular conditions.