PubMed Health⌕ Search

Biomedical subjects

B H Meyer

Publications and source records attributed to B H Meyer.

At least 37 records · Page 2Linked to original sources
PubMed1987

The effects of forskolin eye drops on intra-ocular pressure.

Two studies were performed to investigate the effects of forskolin (Hoechst Research) on intra-ocular pressure (IOP). In the first study two 1.0% formulations of forskolin eye drops were compared with placebo in 10 healthy volunteers. Oxybuprocaine eye drops were used for local anaesthesia before measurement of IOP by applanation tonometry. This was followed by instillation of either medication or placebo on a randomised cross-over basis and hourly measurement of IOP. No significant differences were present between the forskolin treatments and placebo. For 6 hours after drug application a definite decrease in IOP relative to base-line values was observed after each of the forskolin treatments as well as after placebo. In a subsequent study only one formulation of 1% forskolin was compared with placebo. Proxymetacaine eye drops were used for local anaesthesia. Forskolin resulted in a significant reduction in IOP relative to placebo. It is concluded that forskolin reduces IOP in healthy volunteers, and that oxybuprocaine reduces IOP in its own right.

Adult↗
PubMed1987

Pharmacokinetics of ramipril in the elderly.

Ramipril (HOE 498) is a pro-drug of which the main metabolite (HOE 498 diacid or ramiprilat) is a potent angiotensin converting enzyme inhibitor. Thirteen healthy white volunteers (5 females and 8 males, ages 65 to 76 years) participated in a study to investigate the pharmacokinetics of HOE 498 in the elderly. After administration of 10 mg of HOE 498, sequential urine and serum specimens were obtained for assay of HOE 498 and metabolites (HOE 498-glucuronide, diacid, diacid-glucuronide, diketopiperazine and diketopiperazine acid). Side effects, clinical chemistry and hematology were monitored. HOE 498 reached peak concentrations of 62.4 +/- 23.3 ng/ml in serum after 0.7 +/- 0.3 hours. Serum levels decreased with an apparent half-life of 0.9 +/- 0.4 hours. The diacid was rapidly formed in serum, reaching peak concentrations of 40.6 +/- 14.0 ng/ml after 2.0 +/- 0.6 hours and declining with a half-life of 2.2 +/- 0.5 hours. A prolonged terminal phase of serum concentration versus time curve was observed at concentrations less than 1 ng/ml. The mean recovery of HOE 498 and metabolites in urine, up to 26 hours after administration, was 35 +/- 14% of the dose. The apparent half-lives, calculated from urine parameters, for HOE 498 and the diacid were 2.6 +/- 0.9 and 4.0 +/- 1.1 hours, respectively. The mean peak concentration and half-life of HOE 498 in serum are slightly higher in the elderly than in younger volunteers. Complete urinary collection was not possible, but urinary recovery did not seem different from younger volunteers.

Aged↗
PubMed1986

Kinetics of piretanide absorption from the gastrointestinal tract.

In a recent report, it was shown that the loop diuretic piretanide is rapidly absorbed after placement of a piretanide solution in the duodenum, while the rate of absorption is definitely slower when the drug is instilled into the ascending colon (5). When piretanide is instilled into the stomach, the absorption process does not differ significantly from that after placement in the duodenum, neither with respect to amount nor rate (5). However, it was not clear from this study whether piretanide is directly absorbed from the stomach or rapidly released into the duodenum. In a study with five volunteers piretanide was instilled into the stomach via a gastroscope. The volunteers took part in two trial phases in a randomized cross-over design: in one phase the administration of 6 mg piretanide was preceded by intravenous administration of 40 mg hyoscine-N-butylbromide (HNB) to immobilize the stomach while in the alternative phase this coadministration of HNB was omitted. Furthermore, the volunteers were lying on their left side to avoid the gastric fluid leaking out into the intestine by gravity. From the concentration-time-curves monitored it can be concluded that piretanide is absorbed directly from the stomach for almost all subjects but with different rates. The rate of absorption increases clearly when the immobilizing effect of HNB disappears. It is most probable that returning peristaltic waves and succeeding gastric emptying results in enhanced absorption from the upper intestinal tract. Furthermore, a pharmacokinetic model which takes into account the differences in the rate of absorption along the gastrointestinal tract was adjusted to the data.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Comparative bio-availability of four formulations of furosemide.

Twelve healthy white male volunteers participated in a randomized double-blind cross-over study to compare the bio-availability of four brands of furosemide marketed in the RSA. A 40 mg tablet of each of the following formulations, purchased at random, was administered: Aquasin; Furetic; Lasix; and Puresis. Blood specimens were taken up to 5 hours and urine specimens collected up to 6 hours after medication. The following parameters were used to compare the formulations: (i) area under the plasma concentration time curve (AUC); (ii) maximal plasma concentration of furosemide (Cmax); (iii) time to maximal furosemide plasma concentration; (iv) cumulative urine volumes; and (v) cumulative excretion of furosemide in urine. Lasix was significantly superior to the other three products in respect of AUC and Cmax. With regard to cumulative urine volumes Lasix was significantly (P less than 0,05) superior to Aquasin in the first 3 hours after medication, significantly superior (P less than 0,05) to Puresis and comparable to Furetic over the entire 6-hour collection period. Lasix resulted in a significantly greater cumulative urinary excretion of furosemide than Puresis and Aquasin over the entire collection period. Lasix was superior to Furetic at 6 hours after medication. It is concluded that the bio-availability of Lasix is superior to that of the other products tested.

Adolescent↗
PubMed1985

Effects of piretanide on potassium balance in hypertension.

Ten hypertensive patients completed a trial lasting 12 weeks to measure the effect of long-term treatment with piretanide, a new, powerful 'loop' diuretic, on total body potassium (TBK). After 2 weeks of placebo treatment, they received 6 mg piretanide twice daily. This dose was increased to 6 mg 3 times a day if blood pressure was not satisfactorily lowered after 4 weeks. Blood pressure and plasma potassium levels were measured weekly. The TBK was measured fortnightly. In this study potassium balance was not significantly affected by the administration of piretanide.

Adult↗
PubMed1984

Cardiovascular effects of etilefrine hydrochloride during abdominal aortic surgery.

To counteract the decrease in blood pressure after release of the aortic cross-clamp, 2 mg etilefrine hydrochloride (Effortil; Boehringer Ingelheim) was administered intravenously to 13 patients undergoing aortofemoral bypass operations. It caused a statistically significant increase in mean arterial pressure, cardiac index, pulmonary capillary wedge pressure and left and right ventricular stroke work index. No significant changes were found in total peripheral resistance.

Aged↗
PubMed1984

Effects of tendamistate (an alpha-amylase inactivator), guar and placebo on starch metabolism.

Nine volunteers participated in a double-blind, cross-over study to compare the effects of tendamistate (HOE 467), guar and placebo on starch metabolism. In each phase of the trial they received a maize-meal porridge breakfast. They either received 5 g guar granules before the porridge or 100 mg tendamistate mixed with the porridge, or porridge alone. Sequential plasma glucose concentrations served as a criterion of starch digestion. The area under the plasma glucose curve and maximal glucose concentrations after administration of tendamistate with the starch were significantly lower (P less than 0,05) than after guar and placebo. No significant differences were found between placebo and guar. We concluded that tendamistate effectively attenuates starch digestion and is superior to guar in reducing postprandial glycaemia.

Adult↗
PubMed1984

Effects of tendamistate on postprandial plasma glucose, free fatty acid and triglyceride levels.

A dose of 400 mg tendamistate or a placebo was given to 10 volunteers in order to investigate its effects on plasma glucose, free fatty acid and triglyceride levels after a porridge meal. Each subject participated in two phases, in each of which they ate porridge prepared from 100 g maize meal together with either placebo or tendamistate 400 mg. Serial blood specimens for plasma glucose determinations were taken up to 3 hours after the meal, and those for free fatty acid and triglyceride determinations up to 14 hours after the meal. Side-effects (flatulence and bulky stools) were not severe and were reported after both treatments. Tendamistate administration significantly attenuated postprandial glycaemia; it had no effect on postprandial triglyceride levels and was associated with a reduction in free fatty acid levels.

Blood Glucose↗
PubMed1984

Pharmacodynamics and tolerability of low doses of tendamistate given with starch.

Six healthy male volunteers participated in a double-blind cross-over study in which 12,5 mg, 25 mg, or 50 mg tendamistate (HOE 467), an alpha-amylase inactivator, or placebo were administered with 100 g maize meal, which contains 85,5 g pure starch. Serial blood specimens for measurement of plasma glucose concentrations, which served as a criterion of starch absorption, were taken up to 3 hours after each starch meal, and side-effects were recorded. The administration of HOE 467 with a starch meal resulted in a significant inhibition of starch absorption. Side-effects were not severe. Flatulence occurred in the placebo phase as well as after administration of the active drug. Loose stools were reported by 1 subject after 25 mg tendamistate.

Blood Glucose↗
PubMed1984

Antagonism of diazepam by aminophylline in healthy volunteers.

Six healthy volunteers participated in a randomized, double-blind cross-over study of the effects of intravenous aminophylline on diazepam-induced sedation. Each subject participated in two phases and in each phase received either diazepam (15 mg intravenously) followed by placebo or diazepam followed by aminophylline (2 mg/kg intravenously). Critical flicker fusion times and reaction times were measured sequentially as indices of vigilance. Subjects also assessed their own vigilance on a visual analogue scale. Aminophylline given after diazepam significantly improved vigilance as measured by the visual analogue scale from 60 to 150 min after administration of diazepam, while total reaction time was significantly improved at 90, 210, and 270 min. There was no significant correlation between theophylline plasma levels and its effects on vigilance.

Aminophylline↗
PubMed1983

Inhibition of starch absorption by tendamistate (an alpha-amylase inactivator).

Tendamistate (HOE 467) is an alpha-amylase inactivator. Doses of 100 and 200 mg and a placebo were administered to 6 volunteers in order to investigate the effect of the drug on plasma glucose levels after a bread meal. Each subject participated in three phases, in each of which they received a meal consisting of 200 g white bread together with either placebo or tendamistate 100 or 200 mg. Serial blood specimens for plasma glucose determinations were taken up to 3 hours after the meal. Plasma glucose concentrations served as a criterion of starch absorption. Side-effects (flatulence and/or diarrhoea) were reported after each of the three treatments. The administration of tendamistate together with the bread meal resulted in significant inhibition of starch absorption.

Absorption↗
PubMed1983

The use of renal enzymes as early indication of renal toxicity after multiple-dose administration of aspirin.

Ten volunteers participated in a study comparing the effects on renal enzymes of multiple oral doses of aspirin relative to no treatment. The total urinary output was collected daily for 21 days from all subjects. The first 7 days were treatment-free. During the second 7-day period the subjects received aspirin 1500 mg 3 times daily. This was followed by another treatment-free period of 7 days. The activity of the enzymes alanine aminopeptidase and N-acetyl-beta-glucosaminidase were determined in each daily urine specimen. Statistical analysis revealed that aspirin significantly increased the output of both enzymes.

Acetylglucosaminidase↗
PubMed1983

Pharmacodynamics and urine pharmacokinetics of three doses of piretanide.

Three doses (3 mg, 6 mg and 12 mg) of piretanide, a new high ceiling diuretic, and placebo were given to 8 volunteers to investigate the relationship between the pharmacodynamic parameters, the dose and its urinary excretion. Intake of food and fluid were standardized from 48 h before until 24 h after drug administration. Urinary output, excretion of unchanged drug, and the excretion and clearance of Na+ and K+ were measured hourly for 7 h after treatment. A clear dose-response relationship was found for cumulative urinary output, cumulative excretion of Na+ and K+, clearance of Na+ and K+ and the urinary sodium/potassium ratio. A significant correlation was found between the net urine volume and the excretion of piretanide per time interval. The clearances of Na+ and K+ were significantly correlated with the excretion of piretanide. Clearance values correlated well with corresponding urine volumes.

Dose-Response Relationship, Drug↗
PubMed1983

Pharmacokinetic aspects of the interaction between clobazam and cimetidine.

The pharmacokinetic interaction between clobazam and cimetidine was studied in 9 healthy male volunteers in an open-labelled study. After a single oral dose of clobazam 30 mg, a wash-out period of 14 days was followed by daily doses of cimetidine 1 g for one week. Thereafter a single oral dose of clobazam 30 mg was again given. The plasma concentrations of clobazam and its main metabolite N-desmethyl-clobazam were measured by gas-chromatography. The area under the curve (AUC0-infinity) of plasma clobazam level was significantly larger after pretreatment with cimetidine and the elimination half life of clobazam was significantly longer. There were no statistically significant differences in Cmax and tmax for plasma clobazam. The plasma levels of N-desmethyl-clobazam did not show any significant change after the intake of cimetidine.

Adult↗
PubMed1982

Furosemide chronopharmacology.

Twelve healthy males participated in a trial to determine whether furosemide diuresis and its effects on electrolyte excretion patterns, aldosterone concentrations and renin activity are subject to diurnal variations. Six treatments were give: placebo at 07h00, 13h00 and 19h00 and furosemide 40 mg at 07h00, 13h00 and 19h00. Each subject participated in six phases. It was found that the time of administration of furosemide does not affect the effect of the drug on sodium and potassium excretion and diuresis. There is a tendency for furosemide to elevate serum aldosterone levels and renin activity regardless of the time of administration.

Adult↗