Unless you're taking the time release version of Metoprolol
Succinate, ie. Toprol XL, you are not taking it correctly. Metoprolol
has a relatively short half life of 3 to 7 hours. In other words, when you take it, its medicinal benefit begins to lessen rather quickly. By taking it only once a day, you get a spike followed by a rapid lessening of its effect. People taking Metoprolol Tartrate usually take if twice a day to maintain a relatively stable level of the drug in their system.