Renal hemodynamics and pharmacokinetics of bevantolol in patients with impaired renal function

The effect of celiprolol on glomerular filtration rate and renal blood flow in patients with chronic renal impairment and healthy volunteers

A double-blind, placebo controlled study investigated the effects of celiprolol, 200 mg daily for 7 days, on glomerular filtration rate (GFR) and estimated renal blood flow (ERBF) in eight healthy volunteers and eight patients with chronic renal insufficiency. In healthy volunteers the mean difference in GFR was 4.8 ml min-1 (95% CI -8.2 to 17.7 ml min-1) and the mean difference in ERBF was 49.8 ml min-1 (95% CI -47.5 to 147 ml min-1) after celiprolol. In patients with chronic renal insufficiency the mean difference in GFR was -2.1 ml min-1 (95% CI -64.6 to 65.8 ml min-1). The study had sufficient power to detect a 15% change in GFR for normals and 10% for patients, and for ERBF, changes of 14% and 23% were detectable. Celiprolol at a dose of 200 mg daily for 7 days can be used in patients with chronic renal insufficiency without adversely affecting GFR or ERBF.

Bevantolol disposition in patients with hepatic cirrhosis

Bevantolol is a new, cardioselective beta-receptor antagonist that undergoes extensive hepatic biotransformation. To evaluate changes in the disposition of bevantolol produced by liver disease, a single 200-mg oral dose of bevantolol was administered in ten patients who had hepatic cirrhosis and to ten age-matched controls. Cirrhotic patients had a greater plasma bevantolol half-life (6.9 +/- 4.0 hr, mean +/- SD) then did patients with normal liver function (2.8 +/- 1.1 hr, P less than .01), and they also had a longer duration of significant bevantolol-induced heart rate slowing (for 12 hours after oral dose in cirrhotics versus three hours for controls). On the other hand, the peak concentration after the oral dose and the magnitude of bradycardiac effect were similar for both groups. Plasma bevantolol half-life was more variable in cirrhotic patients than in controls. Some of this variability among cirrhotics was attributable to age, which was a significant determinant of bevantolol half-life in the cirrhotic (but not in the control) patient sample. These results indicate that hepatic cirrhosis alters the disposition of bevantolol and suggest that modifications in bevantolol dose should be considered when using this drug to treat patients with liver disease.

Lipophilicity, hydrophilicity, and the central nervous system side effects of beta blockers

One of the attributes of beta-adrenergic blocking agents that has distinguished these drugs from each other is degree of lipophilicity. While this feature may play a role in facilitating passage across the blood-brain barrier, it is essential to realize that crossing the barrier is not necessarily synonymous with the ability to cause central nervous system (CNS) effects. Several studies have found some degree of CNS side effects, particularly tiredness and fatigue, with atenolol, a hydrophilic beta blocker. Pindolol, a moderately lipophilic beta blocker, has been reported to cause greater disturbances on electroencephalogram (EEG) than propranolol, the most highly lipophilic beta blocker. The investigational agent bevantolol exhibits a moderate degree of lipophilicity and a low frequency of CNS side effects. Drug-induced increases in plasma catecholamine levels, the possible saturation of CNS receptor sites at relatively low drug levels, and the specific structural details of beta-blocker molecules have been suggested as possible contributory factors in determining the degree of CNS effects.

Bevantolol: a beta-1 adrenoceptor antagonist with unique additional actions

Bevantolol is a beta-1 adrenoceptor antagonist that has been shown to be as effective as other beta blockers for the treatment of angina pectoris and hypertension. Some interesting additional properties, such as the absence of the side effect of cold extremities, required investigation, and a great deal of new evidence has been accumulated during the last three years. This new data is consistent with the proposal put forward a couple of years ago that bevantolol interacts with alpha-adrenoceptors. All the available evidence, published and unpublished, has been reviewed and fits into a coherent pattern, here arranged into five sections. Chemistry: affinity for alpha-adrenoceptors. Animal experiments confirm both agonist and antagonist effects on alpha-receptors, in addition to antagonist activity at beta-1 receptors. In addition, bevantolol has electrophysiologic effects, including bradycardia by a direct action on the sinus node and a class 1 antiarrhythmic action. Investigations in humans have shown that although bevantolol has a short half-life, good control of hypertension can be achieved on once-a-day dosing.

SAFETY

bevantolol has remarkably few side effects, does not cause cold extremities, and does not significantly affect glomerular filtration rate in patients with renal impairment. Evidence has been obtained in man for interaction with alpha-adrenoceptors in the brain; and in the peripheral circulation bevantolol does not, as do other beta blockers, increase peripheral vascular resistance, but reduces it. It is suggested that all the additional actions of bevantolol can be attributed to a partial agonist action on alpha-adrenoceptors.