peg asked
I have been taking 25 mg atenolol and doctor switched me to Toprol XL 50 mg. Is this the same strength as the atenolol? Can the pill be cut in half?
Answer
There is no direct conversion from Tenormin (atenolol) to Toprol XL (metoprolol succinate). Generally, when switching between the two, your doctor will pick a similar "potency range" for the specific medication. In addition, there are published guidelines and dosage recommendations based on the indication the drug is being used for.
Dosage Conversation Between Atenolol and Toprol XL
Atenolol comes in the following dosages:
- 25 mg
- 50 mg
- 100 mg
Toprol XL comes in the following dosages:
- 25 mg
- 50 mg
- 100 mg
- 200 mg
As mentioned, there is no direct conversion between atenolol and metoprolol succinate. However, if you were taking 25 mg of atenolol, it makes sense that you would be initiated on a low dose of metoprolol succinate, around 25 to 50 mg. In addition, the appropriate dosage depends on the specific indication being treated (e.g. angina, heart failure etc...). Below are some common indications and appropriate dosages based on those indications.
Common Toprol XL Dosages
Angina
Initiate therapy with 100 mg once daily. Effective doses can range from 100 mg to 400 mg per day.
Heart Failure
Initiate therapy at 25 to 50 mg once daily for Class II heart failure or 12.5 mg once daily for severe heart failure.
High Blood Pressure
Initiate therapy at 50 mg once daily and increase to appropriate response, up to 100 mg once daily.
Toprol XL can be split in half. Please see this article for a full explanation.
Common Atenolol Dosages
Angina
Initiate therapy at 50 mg once daily and increase to appropriate response, up to 100 mg once daily.
Post Myocardial Infarction
Initiate therapy at 50 mg twice daily (or 100 mg once daily).
High Blood Pressure
Initiate therapy at 25 to 50 mg once daily and increase to appropriate response, up to 100 mg once daily.
