Coreg CR 20mg Daily Equivalent in Short-Acting Carvedilol
The equivalent twice-daily dose of immediate-release carvedilol for Coreg CR 20mg once daily is carvedilol IR 6.25mg twice daily (12.5mg total daily). 1
Dosing Conversion Between Formulations
The 2022 AHA/ACC/HFSA Heart Failure Guidelines provide clear dosing equivalents for carvedilol formulations 1:
- Carvedilol CR 10mg once daily = Carvedilol IR 3.125mg twice daily
- Carvedilol CR 20mg once daily = Carvedilol IR 6.25mg twice daily
- Carvedilol CR 40mg once daily = Carvedilol IR 12.5mg twice daily
- Carvedilol CR 80mg once daily = Carvedilol IR 25mg twice daily
Pharmacokinetic Equivalence
Both formulations demonstrate bioequivalence when dosed appropriately, with similar area under the curve (AUC), maximum plasma concentration (Cmax), and trough concentrations for both R(+) and S(-) enantiomers. 2, 3 The controlled-release formulation delays Cmax by approximately 3-3.5 hours compared to immediate-release, but maintains equivalent beta-blocking effects over the 24-hour dosing interval 2, 3.
The peak-to-trough fluctuation in plasma concentration is similar between once-daily CR and twice-daily IR formulations, with a fluctuation index ratio of approximately 1.0 3.
Clinical Considerations for Conversion
- The conversion maintains equivalent beta-1 adrenergic blockade throughout the 24-hour period 2
- No dose adjustment or titration period is required when switching between equivalent doses 3
- Adverse events may be less frequent with CR formulation (59.1%) compared to IR formulation (77.5%), particularly dizziness and headache 2
Target Dosing for Heart Failure
For patients with heart failure with reduced ejection fraction (HFrEF), the target dose is carvedilol IR 25-50mg twice daily (or Coreg CR 80mg once daily for patients >85kg), starting from 3.125mg twice daily and uptitrating every 1-2 weeks as tolerated 1, 4. The mean dose achieved in clinical trials was 37mg total daily 1.