Beta-Blockers Not Good First-Line
Hypertensive Medications: In a
meta-analysis of the best 13 randomised controlled trials available (n=105 951)
comparing beta blockers with other antihypertensive drugs or placebo or no
treatment, the relative risk of stroke was 16% higher for beta blockers than for
other drugs. There was no difference for myocardial infarction. When the effect
of beta blockers was compared with that of placebo or no treatment, the relative
risk of stroke was reduced by 19% for beta blockers, about half that expected
from previous hypertension trials. There was no difference for myocardial
infarction or mortality. Authors state that beta blockers should not remain a
first choice in the treatment of primary hypertension and should not be used as
reference drugs in future studies. Should
beta blockers remain first choice in the treatment of primary hypertension? A
meta-analysis. Lindholm LH, et al.
Umea
University
Hospital
,
Umea
,
Sweden
. Larsh.lindholm@fammed.umu.se.
Lancet. 2005 Oct 29-Nov
4;366(9496):1545-53.
Beta-Blocker
Reduced Endurance: Endurance time
was reduced 35% by atenolol but not by transdermal clonidine or placebo. Neither
active drug interfered with the progress of the conditioning program, Comparative
effects of transdermal clonidine and oral atenolol on acute exercise performance
and response to aerobic conditioning in subjects with hypertension. Arch
Intern Med. 1989 Jul;149(7):1551-6
Beta-Blockers Compared: Numerous
beta-blockers are available. A mortality benefit after heart attacks has been
shown for propranolol, timolol, metoprolol, and, in the presence of left
ventricular dysfunction, carvedilol. In heart failure, the selective metoprolol
and bisoprolol as well as the nonselective agent carvedilol (which possesses
alpha-blocking properties) have a demonstrated mortality benefit. Not all
tolerated beta-blockers are associated with a survival benefit and it is
probably not advisable to extrapolate benefits to all drugs with similar
(although probably not identical) properties. Carvedilol may have advantages
over other beta-blockers and a possible survival advantage, suggested by the
recent Carvedilol or Metoprolol European Trial (COMET). Cardiovascular
drug class specificity: beta-blockers. Reiter MJ.
University
of
Colorado
. Prog Cardiovasc Dis. 2004
Jul-Aug;47(1):11-33
Beta-Blockers, Diuretics Reduce
Fractures: A case-control analysis
using the
UK
General Practice Research Database included
30,601 adults ages 30-79 with a fracture vs. 120,819 controls. The most frequent
fractures were of the hand/lower arm (42%) and of the foot (15.1%). Compared
with patients who did not use either beta-blockers or thiazide diuretics, the OR
for current use of beta-blockers only was 0.77; for current use of thiazides
only, 0.80; and for combined current use of beta-blockers and thiazides, 0.71.
Data were adjusted for smoking; body mass index; number of practice visits; and
use of calcium channel blockers, angiotensin-converting enzyme inhibitors,
antipsychotics, antidepressants, statins, antiepileptics, benzodiazepines,
corticosteroids, and estrogens. Many elderly patients with hypertension who are
at risk of developing osteoporosis may potentially benefit from combined therapy
with beta-blockers and thiazides. Use of beta-blockers and risk of fractures. Schlienger RG, Kraenzlin ME,
et al,
University
Hospital
,
Basel
,
Switzerland
. JAMA.
2004 Sep 15;292(11):1326-32
Carvediol (Coreg)
Appears Better than Metoprolol
for Diabetes on ACE Inhibitor:
RAS
) blockers (ACE inhibitors or angiotensin II receptor blockers),
patients were given 6.25- to 25-mg dose of carvedilol (n = 498) or 50- to 200-mg
dose of metoprolol tartrate (n = 737), each twice daily. Hydrochlorothiazide and
a dihydropyridine calcium antagonist were added, if needed, to achieve blood
pressure target. The mean HbA1c increased with metoprolol (0.15%; P<.001) but
not carvedilol (0.02%; P = .65). Insulin sensitivity improved with carvedilol
(-9.1%; P = .004) but not metoprolol (-2.0%; P = .48). Blood pressure was
similar between groups. Progression to microalbuminuria was less frequent with
carvedilol than with metoprolol (6.4% vs 10.3%; P = .04).
Metabolic effects of carvedilol vs metoprolol in patients with type 2 diabetes
mellitus and hypertension: a randomized controlled trial. Bakris GL, Fonseca V,
et al.; GEMINI Investigators.
Rush
University
,
Chicago
.. JAMA.
2004 Nov 10;292(18):2227-36. Ed: Carvediol is unfortunately very
expensive at $121 per month or more vs. $15 for metoprolol at Walgreens
1/2/05. The minor benefit on lab values of carvediol must be shown to have
a significant long term health impact to merit such costs.
Nebivolol Good for Arterial Stiffness: The
vasodilating beta-blocker nebivolol, but not atenolol, was found to increase
arterial distensibility in sheep. Nebivolol
may be of benefit in conditions of increased large artery stiffness, such as
isolated systolic hypertension. Nebivolol
increases arterial distensibility in vivo. McEniery CM, Schmitt M, et al.
University
of Cambridge
,
UK
Hypertension. 2004
Sep;44(3):305-10. Ed: Extensa is a new blood pressure medication
available in England for about $36 per month.
Nebivolol
(Extensa) is a vasodilating β-blocker, combines β-adrenergic blocking
activity with a vasodilating effect mediated by the endothelial L-arginine
nitric oxide (NO) pathway. The blood pressure lowering effect of nebivolol is
linked to a reduction in peripheral resistance and an increase in stroke volume
and preservation of cardiac output. The effects of nebivolol have been compared
with other β-blockers and also with other classes of antihypertensive
agents. In general, response rates to treatment are higher and the frequency and
severity of adverse events are either comparable or lower with nebivolol.
Endothelium-derived NO is important in the regulation of large arterial
stiffness, which in turn is a major risk factor for cardiovascular disease.
Therefore, antihypertensive drugs, such as nebivolol, that also improve
endothelial function and decrease arterial stiffness, may contribute to a
reduction in cardiovascular risk.