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Biomedical subjects

M G Bogaert

Publications and source records attributed to M G Bogaert.

At least 109 records · Page 6Linked to original sources
PubMed1983

Lack of influence of propranolol and metoprolol on walking distance in patients with chronic intermittent claudication.

Ten patients with chronic intermittent claudication were included in a double-blind, randomized cross-over study of placebo, propranolol 80 mg b.i.d. and metoprolol 100 mg b.i.d., each given for two months. At the end of each treatment period, the patients were tested on a treadmill and the time to first claudication pain and to intolerable claudication pain was noted. There was no decrease in time to first claudication pain or to intolerable pain with either propranolol or metoprolol as compared to placebo.

Chronic Disease↗
PubMed1983

Fate of orally given isosorbide dinitrate in man: factors of variability.

After oral administration of isosorbide dinitrate, plasma concentrations of isosorbide dinitrate and mononitrates can be measured. An attempt was made to identify a number of factors which influence these plasma concentrations. Presence of renal failure, acute or chronic treatment with beta-blocking agents, and chronic cimetidine treatment did not influence the plasma concentrations. In a number of patients with cirrhosis, however, plasma concentrations of isosorbide dinitrate were found to be higher than in noncirrhotic patients.

Administration, Oral↗
PubMed1983

Single administration of atenolol does not influence the kinetics of orally given isosorbide dinitrate.

In eight subjects, plasma concentrations of isosorbide dinitrate and its mononitrates after oral administration of 10 mg isosorbide dinitrate were measured on two occasions, once with and once without previous administration of a single dose of atenolol 100 mg. There were no significant changes either in plasma concentration at different times after administration, or in peak plasma concentrations or in area under the curve of the isosorbide dinitrate and mononitrates.

Administration, Oral↗
PubMed1982

High-performance liquid chromatographic determination of metoprolol in plasma.

A high-performance liquid chromatographic method is presented for the determination of metoprolol in human plasma. Metoprolol was extracted from plasma by a single extraction procedure with 4-methylpropranolol as the internal standard. Chromatography was done on a reversed-phase column with fluorescence detection. The minimum detectable concentration was 5.0 ng/ml of plasma. The standard curve was linear in the range evaluated, 10-300 ng/ml. The within-run coefficient of variation was 2.3-6.0%, and the day-to-day variation was 6.8%. The method is free from interference by major metoprolol metabolites.

Chromatography, High Pressure Liquid↗
PubMed1982

Binding of beta-adrenoceptor blocking drugs to human serum albumin, to alpha 1-acid glycoprotein and to human serum.

The binding of 8 beta-adrenergic blocking drugs to human serum albumin, to alpha 1-acid glycoprotein and to serum from normal volunteers and from patients with rheumatoid arthritis was studied. Protein binding was determined in vitro using equilibrium dialysis of labelled drug at 25 degrees C. Oxprenolol and propranolol were highly bound to serum, alprenolol, pindolol and timolol to a lesser degree, and atenolol, metoprolol and sotalol were negligibly bound. For the five compounds which were appreciably bound, the mean binding was significantly higher in serum from patients with rheumatoid arthritis than in serum from normal volunteers. For those drugs, binding to alpha 1-acid glycoprotein was higher than to human serum albumin, and binding to a mixture of both proteins approached that to serum from healthy volunteers. For each of these drugs there was a strong correlation between the serum alpha 1-glycoprotein concentration and the percentage binding.

Adrenergic beta-Antagonists↗
PubMed1982

Plasma concentrations of isosorbide dinitrate and mononitrates after acute and chronic oral administration of isosorbide dinitrate in man.

Isosorbide dinitrate (Cedocard) was given orally to patients in doses of either 5, 20 or 40 mg t.i.d. for 19 days, and the plasma concentrations of unchanged product and of its mononitrates were measured. While the concentration of isosorbide 2-mononitrate remained stable, the concentration of isosorbide dinitrate and of isosorbide 5-mononitrate in plasma increased gradually during the first days of administration. Decrease in presystemic or systemic clearance is probably responsible for this phenomenon.

Administration, Oral↗
PubMed1982

Pharmacokinetics of sulfamerazine and antipyrine in neonatal and young lambs.

The disposition of sulfamerazine after oral and after IV administrations was studied in lambs at different times after birth. There was a gradual increase in systemic clearance and plasma binding until the 9th week. After sulfamerazine was given orally, there was a marked evolution in the shape of the concentration-time curves in function of age, strongly suggesting a defective absorption rate in the first weeks after birth. For antipyrine, too, the clearance increased gradually during the period of study, but absorption seemed to be rapid in the very young animals.

Administration, Oral↗
PubMed1981

Gastric relaxation and vomiting by apomorphine, morphine and fentanyl in the conscious dog.

Apomorphine (0.03 mg . kg-1 s.c.) and morphine (0.5 mg . kg-1 s.c.) produced gastric relaxation and vomiting in the conscious dog. Domperidone (0.1-1 mg . kg-1 i.v.), haloperidol (0.1 mg . kg-1 i.v.) and pimozide (0.025 mg . kg-1 i.v.) selectively blocked the gastric relaxation as well as the vomiting caused by apomorphine. Naloxone (0.07 mg . kg-1 i.v.) selectively blocked the gastric relaxation and the vomiting caused by morphine; after naloxone, morphine produced a delayed gastric relaxation in 2 experiments out of 7. These results suggest that for gastric relaxation as well as for vomiting, apomorphine and morphine act on different receptors. Fentanyl elicited marked gastric relaxation, blocked by naloxone, but did not elicit vomiting. After fentanyl, morphine and apomorphine no longer produced gastric relaxation and vomiting. This observation shows that the known blocking effect of fentanyl at the vomiting center does not affect its gastric relaxing effect.

Animals↗
PubMed1981

High-performance liquid chromatographic determination of propranolol and 4-hydroxypropranolol in plasma.

A high-performance liquid chromatographic method for the simultaneous determination of propranolol and 4-hydroxypropranolol in plasma is presented. The method involves plasma extraction at basic pH with ethyl column, and fluorescence detection. The within-run a reversed-phase column coefficient of variation were 3.0-7.1% for propranolol and 5.8-8.3% for 4-hydroxypropranolol. The day-to-day variations were 4.6 and 8.2% for propranolol and 4-hydroxypropranolol, respectively. The method can detect 1 ng of each compound/ml of plasma.

Chromatography, High Pressure Liquid↗
PubMed1981

Analysis of methoxsalen in plasma by reversed-phase high-performance liquid chromatography.

A high-performance liquid chromatographic method for the determination of methoxsalen in plasma was developed. The method includes extraction from plasma of the drug and the internal standard (5-methoxypsoralen) into methylene chloride. Chromatography was performed on a reversed-phase C8 column connected with a UV detector set at 254 nm. The mobile phase was methanol-acetonitrile-water (2:30:68). For a plasma sample of 0.25 ml, the maximal sensitivity was approximately 10 ng/ml. Accuracy was within 7.5% for therapeutic plasma levels, and the coefficient of variation varied between 4.3 and 0.9% for 28 and 300 ng/ml of plasma, respectively.

Chromatography, High Pressure Liquid↗
PubMed1981

Fate of isosorbide dinitrate and mononitrates in patients with renal failure.

Isosorbide dinitrate 10 mg, isosorbide 5-mononitrate 5 mg and isosorbide 2-mononitrate 5 mg were administered orally to subjects with and without renal failure, and the plasma concentrations of isosorbide dinitrate and of both the mononitrates were measured. There was no striking difference in plasma concentration as a function of time between subjects with and without renal failure, except for a somewhat higher isosorbide 5-mononitrate concentration after administration of this metabolite to uraemic patients.

Adult↗
PubMed1981

Distribution of antipyrine, phenylbutazone and phenytoin in experimental renal failure.

Concentrations of antipyrine, phenylbutazone and phenytoin were measured in serum and in tissues of rabbits with acute renal failure after uranyl nitrate injection, in view of our earlier finding that the volume of distribution of phenytoin and of phenylbutazone is increased in those animals. Concentrations of antipyrine in serum and in tissues were not altered in the uraemic rabbit. For phenylbutazone, total serum concentrations were decreased in uraemic rabbits; concentrations in brain, liver and fat were increased, while concentrations in other tissues and unbound serum concentrations were not significantly changed. For phenytoin, total serum concentrations were decreased and unbound serum concentrations and tissue concentrations were not significantly changed in uraemic rabbits. Calculation brain, liver and fat were increased, while concentrations in other tissues and unbound serum concentrations were not significantly changed. For phenytoin, total serum concentrations were decreased and unbound serum concentrations and tissue concentrations were not significantly changed in uraemic rabbits. Calculation brain, liver and fat were increased, while concentrations in other tissues and unbound serum concentrations were not significantly changed. For phenytoin, total serum concentrations were decreased and unbound serum concentrations and tissue concentrations were not significantly changed in uraemic rabbits. Calculation of the ratios of tissue concentrations over unbound serum concentrations suggests that the increased distribution volume of phenylbutazone and phenytoin in the uraemic rabbit is due to the decreased serum binding rather than to changes in tissue binding.

Acute Kidney Injury↗
PubMed1981

Binding of drugs in serum, blood cells and tissues of rabbits with experimental acute renal failure.

In vitro binding of phenylbutazone and phenytoin was studied in serum in tissue homogenates, in tissue slices and in blood cells of rabbits with acute renal failure induced by uranyl nitrate. For phenylbutazone serum binding was decreased in uraemic rabbits, while the binding in homogenates of kidneys and liver was increased. For phenytoin binding in serum and in homogenates and slices of kidneys was decreased in uraemic rabbits. Binding of phenylbutazone and phenytoin to blood cells was not significantly changed in uraemic rabbits. The changes in tissue binding found are small and are only significant for liver and kidney which represent a small fraction of total body mass. Although the methodology for measurement of tissue binding is not entirely satisfactory, we think we can conclude that these changes probably contribute only to a minor degree to the increase of the volume of distribution found for these drugs in renal failure as already suggested by our in vivo data in the preceding paper.

Acute Kidney Injury↗
PubMed1981

Problems with commercial formulations of 8-methoxypsoralen.

Plasma concentrations of 8-methoxypsoralen were measured in 8 psoriatic patients after administration of two commercial solid formulations and of an 8-methoxypsoralen solution. Systemic availability as measured by the area under the concentration versus time curve was much higher for the solution than for the two commercial formulations. For the solid formulations, a large inter- and intraindividual variation in plasma concentrations was found and in many cases no plasma levels could be measured. Administration of the solution gave always more reproducible plasma concentrations in function of time.

Absorption↗