title: A comparative trial of ordinary metoprolol tablets and metoprolol sustained-release tablets in hypertensive patients at rest and on exercise.
abstract: An open, randomized crossover trial was carried out in 10 patients with hypertension to compare the degree and duration of antihypertensive effect of metoprolol given as 100 mg ordinary tablets twice daily and as single daily doses of a 200 mg sustained-release tablet. Blood pressures and heart rate were measured, at rest and during maximum exercise effort, before treatment, at the second hour after the start of each treatment sequence, and at the end of both 14-day treatment periods: after 12 hours in the case of ordinary metoprolol and after 24 hours with sustained-release metoprolol. The results showed that heart rate was greatly reduced (less than 0.001) both at rest and on exercise at all times studied with both treatments. At rest, blood pressure was significantly reduced except by sustained-release metoprolol at 2 hours. On exercise, blood pressure was also significantly reduced except for the 12-hour value for diastolic pressure with ordinary metoprolol. It is concluded that, for similar reductions in heart rate reflecting satisfactory beta-receptor blockade, the antihypertensive effect of metoprolol given at a dosage of 200 mg per day was more rapid in onset after the ordinary tablet formulation but less marked at 12 hours than at 24 hours after the sustained-release formulation.
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002986:Clinical Trials as Topic; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage*; D008875:Middle Aged; D005082:Physical Exertion; D013607:Tablets
chemical_list: D003692:Delayed-Action Preparations; D013607:Tablets; D008790:Metoprolol