You're right, it's likely not a coincidence. One of the side effects of beta-blockers (like the Toprol XL) would be sexual dysfunction. Other antihypertensives can also cause sexual dysfunction as well, but not to the level of beta-blockers.
If there continues to be problems, I would continue to modify your blood pressure medication regimen to see which one minimizes the side effects.
A testosterone level can also be considered to ensure a low level isn't the problem.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b