What's the difference between metoprolol succinate and metoprolol tart?

Medication duration. Succinate (toprol) is the long acting form of metoprolol where as tartrate (lopressor) is the shorter acting form. Toprol can be taken once a day and Lopressor (metoprolol tartrate) is usually taken at least twice a day.
Duration of action. Metoprolol succinate is an extended-release version dosed once daily, meanwhile, Metoprolol Tartrate is an immediate-release (short duration) version dosed twice daily for long-term management. Both can treat hypertension and angina (chest pain), however, succinate is also indicated for heart failure and tartrate can be used to treat an acute myocardial infarction (heart attack).