is a drug that originally was intended to be a once a day medication. Nevertheless, in young patients with good kidney function (probably you), then the maximum duration of effect tends to be less than 24 hours, usually around 18 hours, so there could be likely a period of the day when you are not covered (particularly night time if you take the drug early in the morning). Your physician has recommended metoprolol
tartrate TWICE a day, which is the usual dosing
. Your heart rate
appears at goal, between 60 and 80 bpm.
Hope this helps.
Mayo Clinic Rochester