PubMed Health⌕ Search

Biomedical subjects

C Descoeudres

Publications and source records attributed to C Descoeudres.

At least 37 records · Page 2Linked to original sources
PubMed1986

Pharmacokinetics of tenoxicam in patients with impaired renal function.

The pharmacokinetics of tenoxicam after a single oral dose of 20 mg has been studied in 12 patients with various degrees of decreased renal function. Unchanged tenoxicam and its 5'OH-metabolite in plasma and urine were determined by HPLC. The mean areas under the plasma concentration-time curve (138 +/- 53 micrograms/ml X h) and terminal half-lives in patients with impaired renal function did not differ from values previously reported in normal volunteers, nor did the peak concentration of tenoxicam. The half-life of 5'OH-tenoxicam and unchanged tenoxicam where the same. The urinary excretion of 5'OH-tenoxicam fell with decreasing renal function. Thus no dosage adjustment should be necessary and the usual daily dose of tenoxicam may be administered once daily also to patients with renal failure.

Adult↗
PubMed1986

Differential effect of impaired renal function on the kinetics of clavulanic acid and amoxicillin.

Amoxicillin and clavulanic acid are prescribed as a fixed drug combination. The purpose of the present study was to assess the influence of various degrees of renal insufficiency (glomerular filtration rate [GFR], less than 5 to greater than 75 ml/min per 1.73 m2) on the pharmacokinetics of amoxicillin and clavulanic acid following oral (500 and 125 mg of amoxicillin and clavulanic acid, respectively) and intravenous (1,000 and 200 mg, respectively) dosing. The volume of distribution and the systemic availability were independent of the renal function, while the total body clearance and the renal and the nonrenal clearance of amoxicillin and clavulanic acid decreased with decreasing renal function. The decrease in the total body clearance was more pronounced for amoxicillin than for clavulanic acid. This explains the increase in the ratio of the area under the plasma concentration versus time curve of amoxicillin to that of clavulanic acid with decreasing glomerular filtration rate after oral dosing; for example for a GFR of 75 ml/min, the ratio of amoxicillin to clavulanic acid was 4.9 +/- 1.2; for a GFR of 35 to 75 ml/min, 5.3 +/- 2.4; for a GFR of 10 to 35 ml/min, 11.9 +/- 5.8; for a GFR of 5 to 10 ml/min, 13.4 +/- 9.1; and for patients on hemodialysis, 14.7 +/- 5.3. Dosage recommendations are suggested which prevent undue accumulations of amoxicillin while maintaining adequate concentrations of clavulanic acid.

Amoxicillin↗
PubMed1986

Biocompatibility of different hemodialysis membranes: activation of complement and leukopenia.

The ability of three hollow-fiber dialyzers (Cuprophane [CU], polymethylmethacrylate [PMMA], and polyacrylonitrile [PAN]) to activate complement and to induce leukopenia was studied prospectively in six patients on long-term hemodialysis. CU membranes caused the most intense complement activation with C3a, C3d, and C5a levels peaking 15 min after beginning dialysis. Total white blood cell (WBC) counts dropped simultaneously by 76%, and the decrease in leukocytes was inversely correlated with the levels of C3a and C5a. In contrast, PMMA membranes led only to slight complement activation with an associated fall in WBC counts of 29%, and PAN membranes induced very little complement activation without leukopenia. In vitro studies involving incubation of normal human plasma with each of the three membranes corroborated these findings. The results suggest that the biocompatibility of PMMA and PAN dialyzers is superior to CU.

Acrylic Resins↗
PubMed1984

[Hepatitis B vaccination].

Since 1982 two hepatitis B (HB) vaccines have been commercialized. Both contain mainly non-infectious hepatitis B surface antigen particles and are manufactured from purified and inactivated plasma of healthy HBs-antigen carriers. H-B- Vax (Merck, Sharp & Dohme) is administered intramuscularly in two 20 micrograms doses one month apart, followed by a booster injection six months after the initial dose. Hevac B Pasteur is injected subcutaneously in three 5 micrograms doses at monthly intervals, with a booster dose 12 months after the first. Side effects are mild and not significantly more frequent than after placebo. Both vaccines are effective, as shown by the appearance of antibodies against HBs antigen in over 95% of healthy vaccines. HB infection occurred only in the first months after vaccination and in people with insufficient antibody response. Patients with compromised immune reactivity, such as those with endstage renal failure or with a transplanted organ, develop anti-HBs less often and also in lower titers than healthy individuals. In Western Europe and in the United States HB vaccination should be restricted to persons at high risk such as medical and dental personnel, patients with endstage renal failure, i.v. drug users, male homosexuals, close contacts of HBs carriers, refugees from countries with high HB endemicity and travellers to such countries. In developing countries with very high prevalence of hepatitis B, extensive programmes of vaccination in infants should be initiated. Serotesting before vaccination is only useful in people with an exposed probability of positive HBV markers well over 10%. Serotesting after vaccination should be done in health care personnel where non-responders can be protected with intermittent injections of HB immunoglobulin. In selected cases combined passive-active immunization may be useful.

Antibodies, Viral↗
PubMed1984

Interferon as an adjuvant for hepatitis B vaccination in non- and low-responder populations.

To determine the effect of interferon on the production of antibodies against hepatitis B virus, recombinant alpha-interferon was added only to the fifth vaccine injection in a non-responder group and to all three initial vaccine injections in a low-responder group. In the non-responder group, 27% of the hemodialysis patients, 7% of the renal transplant patients, and both medical staff members tested developed low serum concentrations of anti-HBs (less than 25 mU/ml). Whereas in the low-responder group 60% of the hemodialysis patients developed the same amount of antibodies as a placebo group of comparable patients (greater than or equal to 25 mU/ml), 78% of the renal transplant patients showed a 25% higher antibody concentration than a placebo group (half less than 25 mU/ml;half less than 50 mU/ml). According to these preliminary findings alpha-interferon may have an adjuvant effect on hepatitis B vaccination.

Adjuvants, Immunologic↗
PubMed1983

Immunogenicity of a hepatitis B subunit vaccine in hemodialysis and in renal transplant recipients.

A hepatitis B subunit vaccine was given to 59 medical staff members, 106 hemodialysis patients and 28 renal allograft recipients. The vaccine consisted of formalin-inactivated hepatitis Bsurface antigen (HBsAg) and was given in 3 doses (times 0, 1 and 6 months) of 20-40 micrograms. Some of the vaccinees received anti-HBs antibodies together with the first vaccine dose (active/passive vaccination). One month after the last infection, 93% of the medical staff members who had received active/passive immunisation and 97% of those who had received active immunisation had detectable anti-HBs antibodies with mean titers ranging from 1:512 to 1:1024. In the group of hemodialysis patients antibodies were detectable in 63-65% of the individuals who had received active or passive/active immunisation in mean titers between 1:32 and 1:64. Finally, only 32% of the renal allograft patients developed measurable anti-HBs antibodies, the titers of responders being still lower than in the hemodialysis patients. Side effects occurred following 10% of all vaccine injections and were always mild in nature. Within the 12 months observation period period following the first vaccination, 3 HBV events occurred in the 193 individuals: One aclinical case detected by a transient seroconversion against the hepatitis B core antigen, one anicteric and one icteric hepatitis case. The data illustrate the difficulties for active immunisation against hepatitis B of hemodialysis patients or of renal transplant recipients.

Antibodies, Viral↗
PubMed1982

Erythrocyte deformability in dialysed and non-dialysed uraemic patients.

In thirty-one uraemic patients, fourteen on conservative treatment and seventeen on long-term haemodialysis, erythrocyte deformability, measured as filtration half-time in a paper filtration experiment, was studied. The two groups were comparable concerning age, sex and kidney disease. Although the mean filtration half-time for erythrocyte suspensions was normal in non-dialysed patients there was a positive linear correlation (P less than 0.01) between serum creatinine and filtration half-time in this group. Filtration half-time was increased in dialysed patients, indicating impaired deformability in the latter (P less than 0.001). Filtration half-time showed a good inverse correlation with the packed red cell volume in the non-dialysed (P less than 0.001) and in the dialysed group (P less than 0.01). As pre- and post-dialysis filtration half-times were the same, it appeared that the more severe uraemic state of dialysed patients was responsible for the impairment of erythrocyte deformability and not the dialysis procedure itself.

Adult↗
PubMed1981

[Continuous ambulatory peritoneal dialysis, advantages and disadvantages].

Continuous ambulatory peritoneal dialysis (CAPD) represents a new method for the treatment of end-stage renal disease. It offers the advantages of greater clearance of higher molecular-weight substances than during haemodialysis, good control of blood pressure, marked improvement of anemia, and unrestricted diet. In contrast, the risks of peritonitis, hypoproteinemia, and hypertriglyceridemia are major disadvantages. Furthermore, CAPD is a time-consuming procedure. In spite of the need for technical improvements, CAPD is even now, for selected patients, a valuable alternative treatment to intermittent dialysis methods.

Ambulatory Care↗
PubMed1980

[The problem of hemoperfusion in poisonings: ineffectiveness in maprotiline poisoning].

A case of self-poisoning with maprotiline presenting with coma stage III was treated by resin hemoperfusion for 9 hours using an XAD-4 resin cartridge. Plasma levels of about 800 ng/ml maprotilin were initially found. After 5 hours of hemoperfusion progredient clinical improvement was noticed without decreasing tendency of the blood drug levels. The theoretical extraction efficiency calculated from the maprotiline blood levels and the perfusion rate yielded 50 mg for maprotiline and 16 mg for desmethylmaprotiline and was in good agreement with 60.5 mg of maprotiline and 17.3 mg of desmethylmaprotiline recovered from the resin cartridge at the end of the hemoperfusion. The in vitro binding capacity for maprotiline was estimated to be 230 mg per g of resin. These results demonstrate that XAD-4 resin efficiently binds maprotiline. However, because of the very low blood concentrations due to the large volume of distribution, whole body concentrations are minimally affected by resin hemoperfusion. Main complications consisted in thrombocytopenia extending over 24 hours after stopping hemoperfusion, anemia, a short initial decrease of blood pressure and an episode of premature ventricular beats.

Anthracenes↗
PubMed1980

Influence of 1,25 dihydroxycholecalciferol on sexual dysfunction and related endocrine parameters in patiens on maintenance hemodialysis.

It has been postulated that hyperparahyroidism is in part responsible for sexual dysfunction in dialyzed patients and that this could improved by 1,25(Oh)2D3. In a single blind study patients on maintenance hemodialysis were treated after a control period with 1,25 (OH)2D3 and with placebo in random order. Sexual performance was assessed with a detailed semistructured psychiatric interview protocol in 14 and several endocrine parameters were analyzed in 15 patients. Under control conditions sexual function was disturbed in 11/14 patients. Plasma testosterone was moderately decreased in men, PRL and PTH levels were distinctly elevated in both sexes. 1,25(OH)2D3 raised serum calcium levels significantly from 9.6 to10.6 mg/100 ml ( P < 0.01) and lowered PTh from 1.39 to 0.82 ng/ml ( P < 0.01). However, no improvement in sexual function (such as libido, frequency of intercourse or masturbation) was found, and apart from a slight rise of testosterone in men and moderate fall of PRl in men and women endocrine parameters remained unchanged. It is concluded that in spite of an improvement of secondary hyperparathyroidism, treatment with 1,25(OH)2D3 for 2 to 4 months was of no value in improving sexual dysfunction in these hemodialysis patients.

Adult↗