Metoprolol Sexual Side Effects
While there are many potential side effects associated with the use of metoprolol, sexual side effects have not been documented in clinical studies as either a common or rare problem. Although sexual side effects such as impotence or decreased sex drive have not been reported with metoprolol, it does not mean that these problems may not occur.
Metoprolol (available as Lopressor®, Toprol XL®, and generic metoprolol) is a beta blocker that is used to treat several conditions, including high blood pressure and angina symptoms. As with all medicines, metoprolol has possible side effects. In clinical studies prior to the approval of metoprolol, there were no reported sexual side effects. Since metoprolol was approved, however, impotence has been reported rarely with this medicine. Sexual side effects, including impotence and a decrease in sex drive, are also reported with other beta blockers.
Before medicines are approved, they must go through several clinical studies where thousands of people are given a particular medicine and compared to a group of people not given the medicine. In these studies, side effects are always documented. This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group of people not taking the medicine. Side effects are then usually separated into those that occur in more than 1 percent of people and those that occur in less than 1 percent of people. Sexual side effects, such as a decrease in sex drive (libido) or impotence, were not reported as either a common or rare side effect with metoprolol during these studies.
Yet, clinical trials are designed to factor out many possible variables in order to understand whether the medicine works and what its possible side effects are. This means that once approved, it is possible that new side effects may occur since a wider range of people are now taking the medicine and for longer periods of time. However, once a medicine is approved, there are usually no more studies conducted on it. Therefore, certain side effects that occur very rarely may never be documented, especially if it is not a serious side effect. The bottom line: in some people, it's possible that a medicine may cause a side effect that hasn't been reported before.