ISSN:
1432-1041
Schlagwort(e):
metoprolol
;
plasma concentration profile
;
controlled-release formulation
;
slow-release formulation
;
exercise heart rate
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
,
Medizin
Notizen:
Summary The plasma concentration-time profile and haemodynamic effects of metoprolol after the administration of metoprolol CR1 (a new multiple-unit controlled-release formulation) and metoprolol SR2 (a traditional slow-release formulation) once daily, were investigated in 12 healthy men. Data were collected over one 24-h dose interval at steady state after five days of treament. The study was a randomized, three-way, crossover comparison of metoprolol CR, 100 mg, metoprolol SR, 100 mg, and placebo. The reduction in exercise heart rate in relation to placebo treatment was used as a measure of β1-blockade. The metoprolol plasma concentration-time profile during treatment with metoprolol CR was smooth and uniform, showing a more controlled release profile than that obtained with metoprolol SR. This was demonstrated by the significantly longer time period during which the plasma concentration exceeded 75% of the maximum concentration (T75), for metoprolol CR compared with metoprolol SR (p〈0.05). The percentage peak-trough fluctuation in plasma metoprolol concentration was significantly smaller for metoprolol CR than for metoprolol SR (p〈0.001). These pharmacokinetic differences between metoprolol CR and metoprolol SR produced a different duration of clinically relevant β1-blockade, defined as a reduction in exercise heart rate of 〉10%. By this definition metoprolol CR was still effective in seven subjects and metoprolol SR in two subjects 24 h after dosing. The percentage peak-trough fluctuation in exercise heart rate over the dose interval was significantly smaller for metoprolol CR than for metoprolol SR (p〈0.001), thus demonstrating a more even β1-blockade with metoprolol CR.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00578407
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