[Evolution of oral drug forms of metoprolol: advantages of long acting modified release forms with modified release].

Review oral modified release drug forms of beta-adrenoblocker metoprolol which is used in arterial hypertension and ischemic heart disease is presented. Metoprolol has salts such as tartrate which is used for production of immediate release (IR) and sustained release (SR) forms and succinate used for production of controlled release form (CR/XL). Metoprolol SR has monolith matrix type, metoprolol CR/XL-system of multiple pellets. Effect of metoprolol tartrate (IR) on mortality was demonstrated in a number of studies in patients with arterial hypertension (AH) (MAPHY), myocardial infarction (SMT, GMT, MIAMI), dilated cardiomyopathy and heart failure (MDC). Studies of efficacy of metoprolol SR are scarce. Antihypertensive efficacy of metoprolol SR in patients with AH did not exceed that of a metoprolol IR or CR/XL. First retrospective analysis of efficacy of metoprolol tartrate and succinate (CR/XL) in patients after myocardial infarction allowed to obtain comparable results of 34% mortality lowering. In a prospective study in patients with chronic heart failure (COMET) metoprolol tartrate IR was not superior to carvedilol when mortality lowering was concerned. At the same time administration of controlled release metoprolol (CR/XL) in 2 large clinical trials (RESOLVD, MERITAHF) was advantageous in patients with chronic heart failure relative to lowering of mortality and rate of hospitalizations. A novel controlled release form of metoprolol has been created as a tartrate salt on the basis of pellet technology (CD/ERT) and its bioequivalence to metoprolol CR/XL has been proved.