PubMed Health⌕ Search

Biomedical subjects

A Brachet-Liermain

Publications and source records attributed to A Brachet-Liermain.

At least 37 records · Page 2Linked to original sources
PubMed1982

[Is it preferable to prescribe 1 or 2 daily doses of sodium valproate?].

Enteric-coated tablets containing 1 500 mg of sodium valproate (VPA) were administered in a randomized fashion either once or three times a day for 7 days to 6 healthy adult volunteers. Plasma total VPA levels and unbound fractions of the drug were determined 2-hourly on the last day of each treatment. Peak plasma concentrations were higher, and minimum plasma concentrations lower with one single dose than with three doses. In subjects who received three doses, the concentration curves tended to plateau, with higher AUC values. However, none of the differences observed reached statistical significance. The clinical implications of these pharmacokinetic data are discussed.

Adult↗
PubMed1982

Liquid chromatography determination of clobazam and its major metabolite N-desmethylclobazam in human plasma.

A specific procedure for the analysis of clobazam and N-desmethylclobazam in plasma is described. Reversed-phase liquid chromatography was performed on a Radial-pak cartridge using a mixture of 45% acetonitrile and 55% buffer solution (pH 7); the ultraviolet detector was set at 254 nm. The method used diazepam as internal standard and diethylether as extraction solvent. The calibration curves are linear between 50 and 500 ng/ml for clobazam and between 100 and 1000 ng/ml for N-desmethylclobazam. The day-to-day precision of the procedure at clobazam plasma concentrations of 50, 250, and 500 ng/ml generated coefficients of variation of 2.2, 6.6, and 11.3%, respectively. No interference occurred in plasma from patients treated with various drugs. The method has been used to study the pharmacokinetics of clobazam and N-desmethylclobazam in patients receiving oral clobazam.

Adult↗
PubMed1981

[Diazepam levels in the ventricular cerebrospinal fluid and peripheral venous blood in man].

Six samples of ventricular cerebral spinal fluid from an external ventricular drain, and peripheral venous blood were taken during the course of parenteral diazepam administration in man. The diazepam level was measured by gas phase chromatography. The levels of diazepam in the CSF were low compared with the plasms concentrations and around the same level as the free circulating fraction. The drug appears in the CSF relatively late after intravenous administration. It would appear that the passage of the drug from the blood into the CSF is slow and not very marked. Therefore it is not the main cause for the pharmocodynamic effects which are the result of the drug passing the blood barrier in the more restricted sense.

Chromatography, Gas↗
PubMed1981

[Trans-placental transfer of four anti-inflammatory agents. A study carried out by in vitro perfusion (author's transl)].

Phenylbutazone, oxyphenylbutazone, ketoprofene and indocid transfer through the placenta (TFp) were studied by perfusing a placental cotyledon at term in vitro. These drugs were used in the therapeutic doses that are employed in human clinical practice. Antipyrine was used as a control material to check the validity of the perfusion in each experiment. TFp of phenylbutazone was 25.83 per cent +/- 0.46, of oxyphenylbutazone 22.48 per cent +/- 1.38, of ketoprofene 35.574 per cent +/- 0.95 and of indomethacin 36.19 per cent +/- 0.26. The authors point out the advantages and the possible dangers of non-steroid anti-inflammatory agents used in pregnant women. They prefer the use of ketoprofene of indomethacin because the anti-prostaglandin properties of ketoprofene are greater although the TFp is significantly less.

Anti-Inflammatory Agents↗
PubMed1980

Meal-dependent absorption of enteric-coated sodium valproate.

The effect of meals on valproic acid (VPA) absorption from an enteric coated (EC) formulation was investigated. In study I, six adult normal volunteers received a single 500 mg dose of sodium valproate in randomized treatments: fasting (A), with a meal (B) or 3 hours after a meal (C). There were significant differences between treatments in the latency period (Lp) defined as the time during which measured concentrations of VPA were less than 1 microgram/ml. Lp values for treatments A, B and C were: 1.67 +/- 1.25 hr, 6.75 +/- 3.98 hr and 7.63 +/- 3.15 hr respectively. In study II, six subjects (five from study I) received in a randomized fashion a 400 mg intravenous bolus dose of VPA and a 500 mg EC VPA tablet, 3 hours after a meal. The mean Lp value was 8.1 +/- 1.6 hr and the mean bioavailability was 100%. Clearance, volume of distribution and half-life values obtained after intravenous dosing were comparable to literature values. These results indicate that food intake delays but does not decrease the extent of absorption of VPA from an enteric coated formulation.

Adult↗
PubMed1977

[Value of anticonvulsant level determination in the treatment of epilepsies].

Phenobarbital and diphenylhydantoin were estimated in treated epileptics. An initial measurement was made in 457 patients. 96% were taking phenobarbital and 53% diphenylhydantoin. Only 37% of the phenobarbital levels and 18% of the diphenhlhydantoin levels were in a therapeutic range. Correlations between the levels, the stability of the epilepsy and signs of overdosage are discussed. Intolerance to phenobarbital reported in some patients, which appears to be real, is not reflected by "normal" or even low blood levels. By contrast, high levels of phenobarbital appear to be well tolerated. Signs of overdosage were quasi-constant when levels of diphenylhydantoin were greater than 15 mg/1. Doses of phenobarbital and of diphenylhydantoin were altered, levels assessed and the clinical condition evaluated in 134 patients. Bringing levels to within the therapeutic range resulted in the disappearance of attacks in 55% of cases for phenobarbital and 30% for diphenylhydantoin. Reduction of doses responsible for excessively high blood concentrations (overdosage) was practically never associated with an increase in the number of attacks. This adjustment is easy for phenobarbital though much more difficult for diphenylhydantoin. In this study, therapeutic levels were 15 to 25 mg/1 for phenobarbital, and 7 to 15 mg/1 for diphenylhydantoin.

Clinical Trials as Topic↗
PubMed1977

[The anti-epileptic drugs].

It is no longer acceptable to prescribe anticonvulsants on the basis of empirical rules. Pharmacological studies have made it possible to measure the absorption, distribution and excretion of these drugs. Complete understanding of this data is neccessary if anticonvulsant prescribing is to be fully effective and to avoid iatrogenic disease.

Age Factors↗
PubMed1975

Absorption of phenobarbital after the intramuscular administration of single doses in infants.

Blood concentrations of phenobarbital, following an intramuscular administration of a single large dose of approximately 10 mg/kg, were studied in 39 infants. A rapid rise was obtained with a mean concentration of 9.30 mug/ml at 30 minutes, 12.76 mug/ml at 90 minutes, and a mean peak concentration of 13.28 mug/ml, which was reached in most cases within 2 hours of injection or less. Cerebrospinal fluid values in 13 patients averaged half the blood phenobarbital concentrations.

Humans↗
PubMedDate not supplied

Diurnal variations in steady-state plasma concentrations of valproic acid in epileptic patients.

Patients on long term valproate treatment exhibit unusual fluctuations in steady-state plasma levels of valproic acid. In order to delineate the underlying mechanisms of these fluctuations, 2 studies were undertaken. In the oral study, 6 epileptic patients received enteric-coated sodium valproate tablets (on a bid regimen for at least 1 month) and plasma levels were monitored on an hourly basis during 24 hours. In the intravenous study, 5 patients received first an intravenous bolus dose (800mg) of sodium valproate followed a week later by a combination intravenous loading dose/constant rate infusion for 36 hours. Plasma valproic acid concentrations were monitored hourly during the infusion study. In the oral study, valproic acid concentrations in all subjects continued to decay for 5 to 6 hours following the 8pm dose. The mean fluctuation in concentrations during 24 hours was 112.8 +/- 31.6%. Consecutive fasting levels were not reproducible. In the intravenous study, small but significant oscillations were present at steady-state; fluctuations ranged from 22 to 34%. However, no circadian rhythm was apparent. On the basis of these findings, it appears that the value of a single fasting sample during therapeutic monitoring of valproic acid is questionable. For an accurate evaluation of valproic acid plasma levels, an average concentration based upon several daily determinations should be performed.

Administration, Oral↗
PubMedDate not supplied

[Nyctohemeral variations of cyclosporine administered orally in renal transplant patients].

The circadian intraindividual variations of cyclosporin blood concentrations were studied in nine renal transplant patients at steady state. The cyclosporin was administrated orally twice a day (9 a.m. and 21 p.m.). Blood concentrations were analysed by H.P.L.C. AUC = area under the drug concentration versus time curve, Cmax = maximum blood concentration, Cmin = minimum blood concentration, Tmax = Time to maximum concentration. Statistical analysis (t, Wilcoxon) shows: AUC, Cmax and Tmax are not significantly modified, Cmin (21) less than Cmin (9) (p less than 0.02). This phenomenon seems to be rather a cyclosporin metabolism variation than an absorption alteration.

Administration, Oral↗