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Biomedical subjects

P Dayer

Publications and source records attributed to P Dayer.

At least 145 records · Page 8Linked to original sources
PubMed1982

[Use of drugs in a medical polyclinic].

The medical prescriptions of 18 house officers working at the Policlinique Universitaire de Médecine in Geneva were analyzed for a period of 17 working days and provide insight into drug therapy chosen for 2194 outpatients at 2694 consultations. These patients were prescribed an average of 1.39 drugs each or 1.13 per call. Of the 298 different drugs thus prescribed, the following were chosen most frequently (in decreasing order): Digoxin, Hygroton, Lexotanil, Metamucil, Voltaren, Aspirin, different insulins and Aldomet. Antimicrobial agents accounted for only 2.5% of all prescriptions, while vitamins and "fortifiers" represent an even lower percentage. It would be possible to limit the number of drugs, since half of the prescriptions cover 23 drugs and 90% of all prescriptions cover 119 drugs. Prescription patterns vary markedly from one subspecialty of internal medicine to another, but also between physicians working in the same field. House officers in charge of given sectors of the city (internists not working in a subspecialty) may thus prescribe between 1,83 and 2.9 drugs per patient, whereas the number of drugs chosen may vary between 81 and 134. Some quaint individual preferences for drugs were also noted and the trend is analyzed. The data is compared with results of the few existing similar studies and offers food for thought on prescription habits, directed ultimately towards a more rational approach to drug therapy for outpatients.

Ambulatory Care↗
PubMed1982

Role of oxidation polymorphism on blood and urine concentrations of amitriptyline and its metabolites in man.

We have measured the metabolites (demethylated and hydroxylated) of amitriptyline in a group of seven normal volunteers. They were phenotyped as extensive or poor metabolizers using debrisoquine and bufuralol. The results demonstrate that the oxidative metabolism (aliphatic hydroxylation) of amitriptyline is under the same genetic control as that of debrisoquine and bufuralol. However, phenotypic polymorphism cannot be used to predict amitriptyline blood concentration after a single oral dose, since the principal metabolic pathway of amitriptyline is demethylation and not aliphatic hydroxylation.

Adult↗
PubMed1981

[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. In addition, from measurement of the exercise-stimulated heart rate it can be concluded that active metabolites of oxprenolol are absent. The duration and intensity of the effect of a single dose of the drug were comparable in the healthy volunteers and the patients with renal insufficiency.

Biotransformation↗
PubMed1981

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 = 3.21 h) was calculated using conventional pharmacokinetic methods. The renal clearance was estimated by plotting urinary excretion rates versus plasma concentrations; for all subjects these plots were curved. In addition to these graphical estimations, the plasma concentrations of pindolol and the urinary excretion data for each volunteer were simultaneously fitted using a one or two-compartment open body model; a computer program using non-linear regression algorithms was used. This procedure did not give an adequate fit to the data. Another type of data analysis, using a population - based model, permitted us to show that the renal elimination of pindolol in man comprises of two separate processes - tubular secretion and reabsorption, which was partially saturable under the experimental conditions. The theoretical relevance and clinical significance of these findings are discussed.

Absorption↗
PubMed1980

[Kinetics of cefoperazone and cefoperazone and cephalothin in rat tissues].

In order to study the behavior of two cephalosporines in various tissues, 100 mg/kg of cefoperazone (CPZ) or cefalotine (CLT) were administered intraperitoneally to Wistar rats. The animals were sacrificed by groups of 6 at intervals ranging from 30 min to 6 hours after the injection and bioassay of the antibiotic was carried out in 9 organs, the serum, and urine. There are marked differences in tissue affinity for each antibiotic, as well as between the tow antibiotics. With the exception of the renal medulla, CPZ penetrates most tissues better than CLT. This difference is particularly striking in the liver. The decline of concentrations is nearly the same in tissues and serum; it is 2--3 times slower for CPZ. Concentration of CPZ exceed 1 microgram/g for more than 6 hours in the kidney and 4 hours in the liver, whereas CLT cannot be quantified after 2 hours in the kidney and after 1 hour in the liver. As has been noted for other antibiotics, plasma protein binding has only limited influence on cephalosporin penetration into tissues. This study of pharmacokinetics in tissues shows that CPZ permeates well those tissues where it is supposed to be effective and remains there longer than CLT. The study illustrates a method which provides a better understanding of the mechanisms responsible for antibiotic action.

Animals↗
PubMed1979

[Pharmacokinetics of a new cephalosporin, cefoperazone].

Cefoperazone is a semi-synthetic cephalosporin for parenteral use with an extended antibacterial spectrum covering Pseudomonas aeruginosa, Enterobacter cloacae and Serratia marcescens. Its pharmacokinetic properties were studied in 8 healthy subjects after 2 intravenous infusions of 2 g of the drug at a 12-hour interval. The mean peak serum concentrations were 134 +/- 16 microgram/ml and 143 microgram/ml. Cefoperazone was shown to possess a long half-life for a cephalosporin (1.7 hours). In our concentration range the drug is 90% protein bound. The apparent volume of distribution was a mean 11.4 liters and the renal clearance 18 ml/min. The cumulative urinary excretion was small, viz. 23% in 12 hours, indicating that there should be no need to modify the dosage regimen in renal failure. Comparison of in vitro studies with the pharmacokinetic properties show that 2 g cefoperazone given intravenously twice a day should inhibit most sensitive bacteria.

Bacteria↗
PubMed1977

[Potassium chloride and non-specific ulcers in the small intestine].

Gut toxicity due to potassium chloride preparations is well known, but there is little information concerning side effects of the newer slow release preparations. Small bowel ulceration due to the new slow release formulation is described. As far as the authors are aware this is the first such case published in Switzerland.

Administration, Oral↗