All generic drugs are not equal.

Problems with generic metoprolol

All generic drugs are not equal.


Many HCM patients have issues with metoprolol, the beta-blocker most widely prescribed for HCM. There may be multiple reasons for this, but a key one has been known for some time: many generic formulations of metoprolol succinate have time-release mechanisms that do not work in a similar fashion to the brand-name Toprol XL.


The result is that patients receive doses that are not equivalent to what was prescribed. Some develop symptoms as a result.

A good summary of the problem

A new blog post by pharmacologist Joe Graedon on The People’s Pharmacy blog describes the problem well.


The HCMA has been aware of this problem for quite some time. It’s caused by lax oversight of generic drugs by the FDA, especially those manufactured in other countries.

How patients can protect themselves

What can HCM patients do? Dr. Lever emphasizes:

  • Check the manufacturer of your prescription. It is usually on the pill bottle. If not, you can check using the number on the pill, on
  • If you do well on your prescription, insist on the same manufacturer.
  • Ask your doctor to write the prescription for that particular manufacturer.

Further information

You can find useful information in our video library, especially in these interviews: