Bisoprolol: a cardioselective β-blocker
1
Bisoprolol: 0 co,dlo •• lective The cardioselectj"i ly of the fj·blocker bisoprolol [EMD·33312; E. Merck] was assessed by using displacement 01 the isoprenaline [isoproterenol) dose- response curve as an indicator of its bronchial (3- blockade, and reducti on in exercise heart rate as an indicator of its cardiac p-blockade. Eight healthy vol unteers took oral bisoprolol 20 and 4Omg, propranolol BOmg , melroprolol 200mg and placebo in random order on 5 dilferent occasions separated by al least 4 days. Alter 90 min and an assessment period, they inhaled at least 8 increasing doses of isoprenaline so that cumulative doses from 10 to were achieved after placebo, metoprolol and bisoprolol, and from 10 to 7450j.l.g alter propranolol. None 01 the drugs significantly chang ed specific airway conductance, thoracic gas volume or the slope of the isoprenaline dose-response curve. The position of the curve was no t significantly changed by bisoprolol 20mg or metoprolol 2OOmg, but was significantly displaced to the right by bisoprolol 40mg and propranolol OOmg . Mean isoprenaline dose ratios were 1.05 for bisoprolol 2Omg , 3.4 f or bisoprol ol 4Omg , 1.4 for meloprolol and 30.2 for propranolol. In a second part 01 Ihe study , t he subjects carr ied ou l steady-state exercise for 5 min at 70% of their maximum exercise work rale. Heart rate was measured before and after exercise. On 5 separate occasions, subjeCIS were given 1 of the 5 drug treatments and 2 hours later repeated the exercise lest. Placebo reduced the exercise heart rate by a mean 01 3%, compared with 26% for metoprolol, 20% for propranolol, 24% for bisoprolol 20mg an d 25% for bisoprolol 4Omg . The ,s-blockers had significantly more effect than placebo, and propranolol caused signi fi cantly less effect than metoprolol and bisoprolol. Bisoprolol caused less bronchial Q-blockade than propranolol but a greater reducti on in exercise heart rate. The results with bi soprolol are similar to those wi th me toprolol and indicate lhat the 2 drugs have a similar ca rdi oselec tivity. fallCfsflf!ld. A.E tl l BI Bt,/,sh Joumalol Clinical Phatmacclogy 18, J43 (Sop 19tU} OlS6·2703/ 84/ I02tu:1OO4/0S 01 .00/0 e ADiS Press
Transcript of Bisoprolol: a cardioselective β-blocker
Bisoprolol : 0 co,dlo •• lective ~-blocke,
The cardioselect j"ily of the fj ·blocker bisoprolol [EMD·33312; E. Merck] was assessed by using displacement 01 the isoprenaline [isoproterenol) doseresponse curve as an indicator of its bronchial (3-blockade, and reduction in exercise heart rate as an indicator of its cardiac p-blockade. Eight healthy volunteers took oral bisoprolol 20 and 4Omg, propranolol BOmg, melroprolol 200mg and placebo in random order on 5 dilferent occasions separated by al least 4 days. Alter 90 min and an assessment period, they inhaled at least 8 increasing doses of isoprenaline so that cumulative doses from 10 to 780~g were achieved after placebo, metoprolol and bisoprolol , and from 10 to 7450j.l.g alter propranolol. None 01 the drugs significantly changed specific airway conductance, thoracic gas volume or the slope of the isoprenaline dose-response curve. The position of the curve was not signif icantly changed by bisoprolol 20mg or metoprolol 2OOmg, but was significantly displaced to the right by bisoprolol 40mg and propranolol OOmg. Mean isoprenaline dose rat ios were 1.05 for bisoprolol 2Omg, 3.4 for bisoprolol 4Omg, 1.4 for meloprolol and 30.2 for propranolol.
In a second part 01 Ihe study, the subjects carried ou l steady-state exercise for 5 min at 70% of their maximum exercise work rale. Heart rate was measured before and after exercise. On 5 separate occasions, subjeCIS were given 1 of the 5 drug treatments and 2 hours later repeated the exercise lest. Placebo reduced the exercise heart rate by a mean 01 3%, compared with 26% for metoprolol, 20% for propranolol, 24% for bisoprolol 20mg and 25% for bisoprolol 4Omg. The ,s-blockers had significantly more effect than placebo, and propranolol caused signi ficantly less effect than metoprolol and bisoprolol.
Bisoprolol caused less bronchial Q-blockade than propranolol but a greater reduction in exercise heart rate. The results wi th bisoprolol are similar to those wi th metoprolol and indicate lhat the 2 drugs have a similar cardioselectivity. fallCfsflf!ld. A.E tll BI Bt,/,sh Joumalol Clinical Phatmacclogy 18, J43 (Sop 19tU}
OlS6·2703/ 8 4/ I02tu:1OO4/ 0S01 .00/ 0 e ADiS Press
