From the Guidelines
The equivalent dose of carvedilol to atenolol 50 mg daily is approximately 12.5 mg twice daily (25 mg total daily dose). When switching from atenolol to carvedilol, this conversion provides similar beta-blocking effects, though the medications work somewhat differently. Carvedilol is a non-selective beta-blocker that also has alpha-blocking properties, while atenolol is a selective beta-1 blocker. The twice-daily dosing of carvedilol is necessary because it has a shorter half-life compared to atenolol's longer half-life, which allows for once-daily dosing.
According to the study 1, the usual dose for angina for carvedilol is 6.25 mg twice daily, uptitrated to a maximum of 25 mg twice daily. This suggests that the equivalent dose of carvedilol to atenolol 50 mg daily would be around 25 mg total daily dose, which is consistent with the recommendation of 12.5 mg twice daily.
The European Society of Cardiology guidelines 1 also support this dose, recommending a target dose of carvedilol of 25-50 mg twice daily for patients with heart failure. However, when switching from atenolol to carvedilol, it is essential to start with a lower dose, such as 6.25 mg twice daily, and titrate up as tolerated to reach the target dose, monitoring for potential side effects like dizziness or hypotension due to carvedilol's additional alpha-blocking effects.
Some key points to consider when making this switch include:
- Carvedilol's non-selective beta-blocking and alpha-blocking properties
- The need for twice-daily dosing due to carvedilol's shorter half-life
- The importance of gradual dose titration to minimize side effects
- The need for close monitoring of patients during the transition period, particularly for signs of worsening heart failure, symptomatic hypotension, or excessive bradycardia.
From the Research
Equivalent Dose of Carvedilol to Atenolol
- The equivalent dose of carvedilol to atenolol 50 mg daily is not directly stated in the provided studies, but we can look at the dosages used in the studies to compare their effects.
- In the study 2, 25 mg carvedilol once daily was compared to 50 mg atenolol once daily, and the dosage was doubled if there was inadequate response.
- The study 3 compared 25 to 50 mg carvedilol once daily with 50-100 mg atenolol once daily.
- Another study 4 compared 25 mg carvedilol once daily to 50 mg atenolol once daily as an adjunct to pre-existing hydrochlorothiazide monotherapy.
- The study 5 administered 50 mg carvedilol and 100 mg atenolol in a random order once a day for 2 months to 43 patients with mild to moderate hypertension.
Dosage Comparison
- Based on the studies, it appears that 25-50 mg carvedilol once daily is comparable to 50-100 mg atenolol once daily in terms of antihypertensive efficacy.
- However, the exact equivalent dose of carvedilol to atenolol 50 mg daily cannot be determined from the provided studies, as the dosages used in the studies varied and the studies did not provide a direct comparison of the two drugs at the same dosage.
- The study 6 compared the efficacy of carvedilol and atenolol in patients with stable effort angina, but it did not provide information on the equivalent dose of carvedilol to atenolol 50 mg daily.