Is Extra Dosage Of Metoprolol Advisable Along With Sleeping Aid?

Thank you! I believe it was told to me that metoprolol can still be taken regularly along with a sleep aid. I take less than half the dosage of the sleep aid each night lately. Problem is, I just took about a third of a metoprolol as my cardiologist directed me to do so when my heart races. This is on top of the usual morning dosage.