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Biomedical subjects

B Diquet

Publications and source records attributed to B Diquet.

At least 91 records · Page 5Linked to original sources
PubMed1984

Metronidazole kinetics and bioavailability in patients undergoing gastrointestinal surgery.

Kinetics and bioavailability of metronidazole were studied in 17 patients admitted in our emergency care unit for gastrointestinal surgery. All were treated with intravenous metronidazole (500 mg three times a day) before, during, and for 4 days after surgery. Seven of the patients continued the intravenous regimen and seven were switched to oral therapy with the same dose and dosing interval for 4 additional days. Kinetic evaluations were performed at steady state on days 4 and 8. The main unexpected result was a consistent 51% increase in AUC with no increase in elimination t 1/2 when intravenous was changed to oral therapy. This change was accompanied by an upward 75% shift in the trough metronidazole plasma concentrations. There was no change when patients remained on intravenous metronidazole. Reduction of clearance on oral treatment appears to be the most likely explanation.

Administration, Oral↗
PubMed1982

[Plasma assay of clomipramine and demethylclomipramine by high performance liquid chromatography].

A technique for assay of clomipramine (Anafranil) and its demethylated metabolite by high performance liquid chromatography is described in this study. This technique utilizes an XoA 800 normal phase column and a quaternary solvent composed of dietylamine, water, acetonitrile, and ethanol. Plasma of patients was extracted with hexane in an alkaline medium (pH 10). The use of an internal standard seemed to improve the assay's repeatability. The simplicity and rapidity of this technique should make it a useful aid for determining optimal doses of Anafranil for patients with depression.

Chromatography, High Pressure Liquid↗
PubMed1980

[Plasma estimation of metronidazole by high performance liquid chromatography (author's transl)].

A rapid and sensitive analytic method for metronidazole (Flagyl) using high performance liquid chromatography is described; the use of a column filled with grafted silicium, lichrosorb RP 8, permits the direct injection of a plasma treated with perchloric acid and then centrifuged. The coefficients of capacity of metronidazole and of the internal standard solution were respectively 4,8 and 11,5. This technic permits one to carry out as a routine estimations of metronidazole, used in the treatment anaerobic gram negative septicemias.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Drug monitoring of clomipramine and desmethylclomipramine in depressed patients using a new liquid chromatographic assay.

A method has been developed for the quantitative analysis of clomipramine and its major metabolite desmethylclomipramine in plasma, using normal phase chromatography with UV detection at 254 nm. This rapid (6 min) and highly sensitive methodology (detection limits 0.5 ng/mL and 2 ng/mL for clomipramine and desmethylclomipramine, respectively; S/N = 3, 0.001 aufs) allows pharmacokinetic studies and drug monitoring of the two compounds. Using the described methodology we report an application which involved 10 depressed inpatients.

Aged↗
PubMedDate not supplied

Beraprost sodium-fluindione combination in healthy subjects: pharmacokinetic and pharmacodynamic aspects.

Beraprost sodium (BPS), an orally active PGI2 (prostaglandine 12) analogue possesses vasodilatating and platelet aggregation inhibiting properties. It is being developed in peripheral arterial occlusive disease. As in future clinical practice BPS might be co-prescribed with oral anticoagulants, we investigated its interaction with fluindione, a vitamin K antagonist in healthy subjects in a randomised, double-blind, placebo-controlled, crossover study. Twelve healthy Caucasian male subjects randomly received BPS 40 microg t.i.d. or placebo for 3 days. There was a 7 day wash out between the two treatment periods. On day 3 of each treatment, the subjects ingested concomitantly a single oral dose of 20 mg of fluindione. The main assessment criterion was fluindione's pharmacokinetics. Secondarily, pharmacodynamic measurements of coagulation (prothrombin time, and International Normalised Ratio, INR) and platelet function (in vitro closure time assessed by PFA-100) were performed. Fluindione was assayed by HPLC with UV detection up to 96 h post-drug. No statistical difference could be evidenced on any fluindione pharmacokinetic parameters between BPS and placebo phases: t 1/2 (h): 35.9 (8.2) vs. 34.0 (4.2) [90% CI 105.8 (95.5-116.2)]; T(max) (h): 2.0 (0.5-6.0) vs. 4.0 (0.5-6.0) [90% CI 136.4 (70.7-208.9)]; Cmax (mg/L): 3.1 (0.6) vs. 2.9 (0.5) [90% CI 94.1 (85.8-103.2)]; AUC 0-inf (mg/h/L): 117.0 (31.5) vs. 113.9 (33.8) [90% CI 97.6 (87.5-108.8)]. The studied doses of BPS did not affect platelet function, at least as assessed by the in vitro platelet function testing. Twenty milligrams of fluindione marginally modified the PT ratio and INR, however, no statistically significant difference was found between BPS and placebo phases. In conclusion, a 3 day regimen of BPS 40 microg t.i.d. by oral route does not seem to affect pharmacokinetic parameters of a fluindione 20 mg single dose.

Administration, Oral↗
PubMedDate not supplied

An in vivo pharmacokinetic/pharmacodynamic model for antiretroviral combination.

PURPOSE: The objective of this study was to investigate the pharmacokinetic/pharmacodynamic properties of an antiretroviral therapy in HIV-infected patients. METHOD: Eight HIV-infected patients received zidovudine, lamivudine, and indinavir as their first antiretroviral treatment. Pharmacokinetic data were analyzed separately using a one-compartmental model with first-order absorption, and the individual estimates were used to simulate drug concentrations. To determine the relationship between drug concentrations and the antiviral effect, an in vitro E(max) model was tested. Alternatively, a dynamic model was built describing the viral and cellular pathophysiology, including the turnover of viral replication in infected cells and the production of virus under treatment. RESULT: The E(max) model fit poorly the experimental data. The complex model was not identifiable with the data available in this study, however a simplified model allowed us to estimate the pharmacodynamic parameters reflecting the decrease of both infected cells and viral load under antiretroviral treatment. CONCLUSION: Using potent highly active antiretroviral therapy, the treatment was so effective that it was not possible to estimate the parameters of the relationship between drug concentrations and the reduction of viral load. Even if the relationship does exist, the direct response model of antiretroviral agents cannot be demonstrated, however the simplified model provides an understanding of the synergy of such a combination and offers suggestions as how to prevent the emergence of viral resistant strains.

Adult↗
PubMedDate not supplied

[Study of gastric elimination of ornidazole after intravenous administration in patients undergoing digestive surgery].

In a previous study, performed in patients undergoing gastrointestinal surgery receiving antibiotics intravenously we pointed out that the gastric aspiration was an additional route of elimination for some drugs. In order to estimate the extra-dose required to replace losses in patients receiving ornidazole, a study was set up. 8 patients entered the trial; the patients were infused 500 mg of ornidazole for 3 days every 12 hours. Blood was sampled at 0-2-4-8-24 h after the last infusion. Urines and gastric aspirate were collected. The results indicate that the amount aspirated through the tubings is 69.1 +/- 37.5 mg per 24 hours (24.8 - 116.8) with a very high variability; the half-life was not different of what is known for ornidazole: 10.5 +/- 1.7 h. The results confirm that for the molecules weakly bound to protein which "concentrate" in the gastric secretion, the aspiration is an important route of elimination.

Aged↗
PubMedDate not supplied

[Effects of 3 doses of maprotiline (25, 50 and 75 mg) on alertness and memory in healthy volunteers].

The effects on psychomotor and mnesic performance of acute oral doses of maprotiline (25, 50 and 75 mg) were evaluated in twelve healthy men in a placebo-controlled double blind study. A battery of tests was performed comprising: objective measures (critical flicker frequency, choice reaction time, memory tasks) and self rating evaluation (visual analogue scales). Tests session took place 15 hours after each treatment. Plasma concentrations of maprotiline were determined. Compared with placebo, maprotiline induced psychomotor impairment on both objective and subjective assessment in a dose related manner. No significant difference between maprotiline and placebo on memory test could be evidenced.

Adult↗