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Biomedical subjects

R Verbeeck

Publications and source records attributed to R Verbeeck.

28 records · Page 2Linked to original sources
PubMed1991

Toxicity of litholytic ethylenediaminetetraacetic acid solutions to the urothelium of the rat and dog.

The toxicity to the urothelium of bipotassium ethylene-diaminetetraacetic acid (K2-EDTA) buffered with 0.2 M triethanolamine (TEA) at pH 8 and 8.5 was tested in rats and dogs. Even at a low concentration of 3.125 mM, K2-EDTA is very noxious to the bladder mucosa. This toxicity is not due to the buffer TEA, which is well tolerated. Although buffered K2-EDTA, at pH 8.5 is an excellent chemolytic agent for calcium-containing stones, its clinical use is limited by this toxicity.

Animals↗
PubMed1991

Toxicity to the urothelium of calcium chelating agents for chemolysis.

Solutions, based on calcium chelating agents, with excellent prospects as litholytic agents in vitro were tested on toxicity to the mucosa of the bladder of the rat. The following compounds were tested at a concentration of 12.5 mM., buffered with triethanolamine 0.2 M at pH 8 and 8.5: ethylenediaminetetra acetic acid with as cation H2+, Li+, Na+, K+, and Cs+, trans-cyclohexane-1.2 diaminetetra acetic acid (cations H+, Na+, K+), diethylenetriamine penta acetate (cations H+, Na+, K+), disodiumethyleneglycol-bis (2 aminoethyl) tetra acetic acid and disodium hydroxyethylethylenediamine tetra acetate. All agents were found to be very noxious to the bladder mucosa of the rat and are unlikely to be safe for clinical use.

Animals↗
PubMed1979

Effect of aluminum hydroxide on diflunisal absorption.

1 The effect of aluminum hydroxide on the oral absorption of diflunisal was studied in healthy subjects. 2 Relative bioavailability of the oral diflunisal dose (500 mg) was estimated by comparison of the areas under plasma concentration versus time curves, and comparison of the amount of drug (unchanged + glucuronides) excreted in the urine. 3 From the AUC-method, a relative bioavailability of 0.60 was calculated. A similar value (F = 0.63) was obtained from the urinary excretion data. 4 The results indicate that co-administration of aluminum hydroxide reduces the bioavailability of oral diflusinal by about 40%.

Aluminum Hydroxide↗
PubMed1979

Pipotiazine pharmacokinetics after p.o. and i.v. administration in man. Correlation between blood levels and effect on the handwriting area.

Plasma kinetics of pipotiazine, a phenothiazine neuroleptic, have been studied in five chronic schizophrenic patients after both oral (25 mg) and i.v. (5 mg) administration of pipotiazine tritiated in the 3- and 4-positions of the piperidine ring. Peak plasma concentrations of unchanged pipotiazine were reached between 1 and 2 h after oral administration and showed a five-fold inter-individual variation. The mean terminal elimination half-life was 11.2 h. After i.v. administration plasma concentration declined bi-exponentially with mean half-life values of 2.7 and 8.8 h. Data indicate that biotranformation of the drug was not dependent on the route of administration and that there were no qualitative differences in biotransformation between individuals. The large apparent distribution volumes (mean value 545 l) indicated extensive binding to tissue components. After 25 mg p.o. effect on the handwriting area was manifest from 8 to 48 h after administration and reached maximum intensity between 24 and 36 h. This is consistent with rather a large duration of action observed clinically.

Administration, Oral↗
PubMed1976

The effect of end-stage renal failure and haemodialysis on the elimination kinetics of sotalol.

A single oral dose of sotalol (160 mg) was administered to control subjects with normal renal function and patients with chronic renal failure in the interdialysis period to estimate the elimination kinetics of the drug. Sotalol concentrations in body fluids were measured fluorimetrically using a modified Garrett and Schnelle (1971) method. Mean plasma half-life (T 1/2) was approximately 5 h in normals, 42 h in patients off-dialysis. During haemodialysis the mean plasma half-time was on the average 7 hours. Comulative urinary excretion of the drug was considerably lower in the patient group: 9% of the dose in 48 h as opposed to 61% in normals. Comparison of sotalol concentrations in plasma versus ultrafiltrate from the coil kidney indicates that the drug in vivo is negligible bound to plasma proteins in remal patients. The net-lowering effect of a 6 to 7 h haemodialysis on the plasma concentration decay line was by 20%. Post-dialysis plasma concentration data suggest that the rate at which sotalol returns to plasma from body tissues appears to be the rate-controlling factor in the elimination of sotalol by haemodialysis.

Adult↗
PubMedDate not supplied

Influence of the hemodialysis on the half-life of practolol in patients with severe renal failure.

Practolol, a recent and more selective beta-adrenergic receptor blocking drug, was given orally as a single dose of 200 mg to seven healthy volunteers and to six patients suffering from severe renal impairment and submitted to the long-term hemodialysis program. The plasma drug decay was markedly slowed and the plasma half-life was prolonged sixfold in the uremic patients in comparison to healthy volunteers. Hemodialysis (8 hours) starting 48 hours after drug intake lowered plasma practolol significantly but transiently. The shorter half-life during hemodialysis and the detection of equally high values of practolol in the ultrafiltrates as in the plasma demonstrate that this drug is readily removable from the plasma. However, the ascending slope of the plasma drug concentration curve which appeared following hemodialysis is suggestive of an incomplete drug removal from the body.

Adult↗