The genetic control of bufuralol metabolism in man.

Bufuralol (Ro 3 - 4787, Angium) is a non selective beta-adrenoceptor blocking drug with some degree of sympathomimetic action and a longer duration of action than propranolol. Plasma concentrations of bufuralol and 1'-hydroxybufuralol, its main blood derivative which shows similar beta-adrenoceptor blocking properties, were determined in healthy volunteers after a 60 mg oral and a 20 mg intravenous dose. Peak plasma concentrations were higher for the parent drug but due to a longer elimination half-life, the metabolite concentrations became higher after a few hours (bufuralol t 1/2 = 2.

[Retention of metabolites of a beta-blocking drug, oxprenolol, in renal insufficiency].

The pharmacokinetics in blood of oxprenolol and its glucuro-conjugated metabolites has been investigated in healthy volunteers and hemodialyzed patients; in addition, the effect of the drug on the heart rate has been measured. Renal insufficiency does not modify the elimination kinetics of oxprenolol, but it does lead to massive retention of the glucuro-conjugated derivatives on multiple dosing. The present study failed to show hydrolysis of the conjugates with liberation of the active parent compound.

Simultaneous tubular excretion and reabsorption of pindolol in man.

The plasma concentrations of pindolol have been examined following the administration of single doses of 15 mg tablets to eight healthy male subjects. The apparent half-life of elimination in plasma (t1/2 = 4.05 h) and in urine (t1/2 = 3.

[Clearance concept applied to pharmacokinetics: 2. Experience with tolamolol (beta-blocking agent) in renal insufficiency (author's transl)].

Tolamolol is subject to first-pass metabolism and is eliminated from the body almost entirely by biotransformation. Its major metabolite in plasma (4-hydroxy-tolamolol) is biologically active and may contribute to the pharmacological effect of the drug. The effect of renal failure on the behaviour of the parent compound and of its metabolite was studied by comparing their kinetics in normal volunteers and in patients with severe renal insufficiency.

[Role of metabolites in the relationship between pharmacokinetics and the effect of beta blockers. Studies on tolamolol and bufuralol].

Plasma concentrations of tolamolol and bufuralol (beta-blocking agents) were measured after oral and intravenous administration to healthy volunteers. The plasma levels of their main metabolite was also determined. Simultaneously, the effect of the drugs on the heart rate and blood pressure was monitored under various stimuli (isoproterenol, exercise or orthostatism) and Valsalva maneuver.

[Pharmacokinetics of two beta blocking drugs: detection of a pharmacogenetic abnormality].

10 healthy male volunteers received orally either 100 mg tolamolol or 20 mg bufuralol. These experiments were repeated by intravenous administration of 10 and 5 mg respectively of these two drugs. Plasma levels of the parent drugs and their main metabolite were measured.