TY - JOUR
T1 - Actions of dilevalol on adrenoceptors
AU - Louis, W. J.
AU - Drummer, O. H.
AU - Tung, L. H.
PY - 1988
Y1 - 1988
N2 - It is not surprising that there has been a search for compounds that combine two useful antihypertensive properties. The expectation is that one such product will offer a simple once-a-day control of blood pressure in a large portion of the population who require drug therapy for their disease. The major disadvantages of the first drug in this class, labetalol, are its poor and variable bioavailability, its relatively short duration of action, and its ability to produce postural hypotension. Attempts to improve the pharmacokinetic deficiencies have given rise to adimolol, which has a prolonged action of up to 90 h in single-dose studies. Of more immediate clinical interest are carvedilol, celiprolol, and dilevalol, each of which appear to have a different mechanism of producing vasodilation. Dilevalol, one of the four isomers of labetalol, is said to form approximately 25% of racemic labetalol. In the pithed rat, both labetalol and dilevalol behave as competitive nonselective β-blocking drugs but dilevalol, unlike labetalol, shows weak α-blocking activity yet produces a dose-dependent fall that is blocked by propranolol, indicating that the drug has a vasodilator action presumably mediated by a β2-agonist effect on β-adrenoceptors. The presence of β2-adrenoceptor agonism of this degree makes this drug extremely interesting. Possible advantages include the ability to produce falls in peripheral resistance without significant postural hypotension, and beneficial metabolic effects and effects on plasma lipids compared with traditional β-adrenoceptor blocking agents that tend to raise blood sugars, interfere with insulin release, lower HDL levels, and raise LDL triglycerides.
AB - It is not surprising that there has been a search for compounds that combine two useful antihypertensive properties. The expectation is that one such product will offer a simple once-a-day control of blood pressure in a large portion of the population who require drug therapy for their disease. The major disadvantages of the first drug in this class, labetalol, are its poor and variable bioavailability, its relatively short duration of action, and its ability to produce postural hypotension. Attempts to improve the pharmacokinetic deficiencies have given rise to adimolol, which has a prolonged action of up to 90 h in single-dose studies. Of more immediate clinical interest are carvedilol, celiprolol, and dilevalol, each of which appear to have a different mechanism of producing vasodilation. Dilevalol, one of the four isomers of labetalol, is said to form approximately 25% of racemic labetalol. In the pithed rat, both labetalol and dilevalol behave as competitive nonselective β-blocking drugs but dilevalol, unlike labetalol, shows weak α-blocking activity yet produces a dose-dependent fall that is blocked by propranolol, indicating that the drug has a vasodilator action presumably mediated by a β2-agonist effect on β-adrenoceptors. The presence of β2-adrenoceptor agonism of this degree makes this drug extremely interesting. Possible advantages include the ability to produce falls in peripheral resistance without significant postural hypotension, and beneficial metabolic effects and effects on plasma lipids compared with traditional β-adrenoceptor blocking agents that tend to raise blood sugars, interfere with insulin release, lower HDL levels, and raise LDL triglycerides.
UR - http://www.scopus.com/inward/record.url?scp=0023805377&partnerID=8YFLogxK
U2 - 10.1097/00005344-198800000-00003
DO - 10.1097/00005344-198800000-00003
M3 - Article
C2 - 2464095
AN - SCOPUS:0023805377
SN - 0160-2446
VL - 11
SP - S5-S11
JO - Journal of Cardiovascular Pharmacology
JF - Journal of Cardiovascular Pharmacology
IS - Suppl. 2
ER -