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Biomedical subjects

G Montay

Publications and source records attributed to G Montay.

53 records · Page 3Linked to original sources
PubMed1989

[Effect of hepatic failure upon the pharmacokinetics of cefixime].

Modifications of cefixime kinetics due to severe impairment of liver function were determined in 9 cirrhotic patients. Cefixime was administered as a single dose of 200 mg and levels were measured by HPLC. Maximum serum concentrations and area-under-the-curves of serum concentrations were not modified. The time for maximum serum concentration was delayed and the cefixime half-life in serum was prolonged, as a reflect of increased volume of distribution resulting from ascites and hypoalbuminemia. Renal clearance increased in these patients, possibly because of reduced extra-renal clearance. No metabolite was detected in serum or urine. Modifications of cefixime kinetics resulting from impaired hepatic function were modest and did not require specific dosage adjustment.

Adult↗
PubMed1988

Bupivacaine pharmacokinetics during epidural anaesthesia in children.

Blood concentrations and pharmacokinetic parameters of bupivacaine were measured after epidural injection in children aged from 1 to 7 years. The children were allocated to two groups. In Group 1 (five children), pharmacokinetic parameters were measured after a single bolus injection of bupivacaine 0.25% with adrenaline 1:200,000. In Group 2 (eight children), pharmacokinetic parameters were measured after the initial injection and the second injection. The same local anaesthetic was used. The volume of the second injection was half of the initial volume. In children of Group 1, maximum mean concentration (CPmax) was 0.64 +/- 0.05 microgram ml-1, time to maximum concentration (Tmax) 19.2 +/- 3.9 min, vascular absorption (T1/2 abs) 4.3 +/- 1.5 min, terminal half-life (T1/2 beta) 227 +/- 37.7 min, volume of distribution (Vd) 3.4 +/- 0.51 kg-1, and total body clearance (Clt) 11.0 +/- 2.0 ml min-1 kg-1. When compared to an adult's pharmacokinetic parameters, both Vd and Clt were increased, so that T1/2 beta remained essentially unchanged. In children of Group 2, the first repeat injection was performed at 110 +/- 6.9 min. Mean CPmax increased significantly (20% after the second injection), whereas the values of the pharmacokinetic parameters measured did not differ significantly from those measured in children in Group 1. The results obtained in the present study demonstrate that the pharmacokinetic parameters of bupivacaine in children do not differ markedly from those reported in adults and that in the recommended dosage, the mean maximum concentrations, even after the second injection, are less than the presumed toxic levels.

Anesthesia, Epidural↗
PubMed1987

Steady-state levels of pefloxacin and its metabolites in patients with severe renal impairment.

Twenty patients (aged 26-70 years) with severely impaired renal function received pefloxacin twice daily for 5 days as 12 mg.kg-1 administered as a 1 h i.v. infusion, or 800 mg administered as tablets. On Day 5 the minimal and maximal plasma concentrations were 5.9 and 11.5 mg.l-1 respectively, after oral administration. The steady-state level of the N-desmethyl metabolite ranged from 0.9 (infusion) to 1.2 mg.l-1 (oral route), and that of the N-oxide metabolite ranged from 6.2 (infusion) to 9.0 mg.l-1 (oral route). The minimal concentration of unchanged drug was related to the age of the patients (infusion), but the N-oxide concentration was influenced by the degree of renal impairment (both routes). The pefloxacin levels were similar to those achieved in healthy subjects, but reduced renal function leads accumulation of its biotransformation products, especially of the N-oxide metabolite which lacks antibacterial activity.

Administration, Oral↗
PubMed1987

[Diffusion of fluoroquinolones in the aqueous humor and crystalline lens].

In 53 patients undergoing cataract extraction, the authors measured pefloxacin and ofloxacin penetration in aqueous humour and lens. Cataract removal was performed at varying times after either the end of one-hour infusion of pefloxacin, ofloxacin per os in one time, or pefloxacin per os during 3 days. In the two first schemes, acme concentrations in aqueous humour are 1.45 mg/l for pefloxacin, 1.14 mg/l for ofloxacin. These concentrations reach the MIC90 of most bacteria usually involved in endophthalmia. The steady state concentrations of pefloxacin are between 6 and 7 mg/l during the first 12 h: they reach the MIC of 80% of Streptococci. There is no evidence of accumulation of pefloxacin in lens; lenticular concentrations of ofloxacin are very low and rapidly decrease.

Administration, Oral↗
PubMed1987

[Pharmacokinetics of pefloxacin in burn patients].

The aim of this study was to evaluate pharmacokinetics of pefloxacin (PFL) in burn patients (n = 11), compared with 5 non burned subjects. The role of the extent of the burn and the delay after initial thermal trauma were also evaluated. Our results suggest that neither the extent of the burn, nor the delay of the study play a role. Compared with non-burned subjects, burn patients exhibit a shorter elimination half-life, but modifications in dosage regimen are not required.

Adult↗
PubMed1986

Penetration of pefloxacin in human heart valves.

Pefloxacin concentrations were measured by HPLC in serum, subcutaneous tissue, heart muscle and heart valves of 41 patients receiving a one hour infusion of 800 mg iv 4, 8, 12, 18, or 24 h before open heart surgery for prosthetic cardiac valve insertion. In all but three of the 46 valvular samples, pefloxacin concentrations were higher than the mode MIC of Staphylococcus, Enterobacteriaceae and Pseudomonas microorganisms causing infections following open heart surgery. Pefloxacin therefore has good penetration of heart valves and is present for up to 24 h. It could be considered as a useful drug in the prophylaxis of cardiac surgery and in therapy of bacterial endocarditis due to susceptible micro-organisms.

Adolescent↗
PubMed1986

Pefloxacin concentrations in human aqueous humour and lens.

In 20 patients undergoing cataract extraction, we measured pefloxacin concentrations in the eye. After a 1 h infusion of pefloxacin 400 mg iv, the mean pefloxacin concentrations 2, 6, 12 and 24 h post-infusion were 0.75, 1.45, 1.04 and 0.86 mg/l, respectively. The simultaneous mean pefloxacin concentrations in the lens were 0.09, 0.20, 0.26 and 0.43 mg/l, respectively. The adequate penetration of pefloxacin into uninfected aqueous humour and lens suggests that this antibiotic may be effective in the treatment of certain bacterial endophthalmic infections.

Aged↗
PubMed1985

Pharmacokinetics of pefloxacin in renal insufficiency.

The kinetics of pefloxacin has been studied after a single intravenous infusion of 8 mg X kg-1 in 15 male patients with various degrees of renal failure. No difference in distribution or elimination of the drug was observed between patients with mild or severe renal impairment. The mean volume of distribution (Vd area) and the mean plasma clearance were 2.03 l X kg-1 and 121.3 ml X min-1, respectively. The mean apparent elimination half-life was 13.5 h. These values are close to those observed in healthy subjects. No accumulation of the active N-desmethylmetabolite was observed in cases of severe failure as compared to mild impairment; its apparent elimination half-life was about twice that of the parent drug. The efficacy of a 4 haemodialysis in 6 additional anuric subjects done to remove pefloxacin from the body was poor.

Adult↗
PubMed1985

Pefloxacin kinetics in cirrhosis.

Pefloxacin pharmacokinetics were evaluated in 16 patients with histologically proved cirrhosis of the liver and compared with those in 12 healthy subjects. In the patients with cirrhosis, the mean (+/- SD) t1/2, although highly variable, was significantly longer (35.10 +/- 19.00 hours) than in the normal subjects (11.00 +/- 2.64 hours; P less than 0.001). In the patients, the volume of distribution was decreased by 18% (P less than 0.02) and total plasma clearance was markedly decreased (2.66 +/- 1.85 vs. 8.19 +/- 2.80 L/hr X 1.73 m2; P less than 0.001). The t1/2 was longer in patients with ascites or jaundice than in patients without these complications. The urinary excretion of unchanged pefloxacin was higher in the patients than in the subjects, while the excretion of N-desmethyl pefloxacin (a major metabolite of the drug) was lower. It is proposed that the decreased plasma clearance of pefloxacin in patients with cirrhosis is a result of decreased hepatic metabolism of the drug, and that the dosage should probably be modified in these patients.

Adult↗
PubMed1984

Absorption, distribution, metabolic fate, and elimination of pefloxacin mesylate in mice, rats, dogs, monkeys, and humans.

Pefloxacin mesylate is well absorbed by the oral route. The antimicrobial activity in dog, cynomolgus monkey, and human plasma was essentially due to unchanged drug which respectively accounted for 64, 94, and 84% of the total activity (ratios derived from relative area under the curve [AUC] values). Half-lives ranged from 1.9 h in mice to 8.6 h in humans. Protein binding was weak, about 20% in plasma. Except in brain, concentrations in most of the organs and tissues tested in rats and dogs were higher than the plasma levels. Microbiological activity in urine was mainly due to pefloxacin and norfloxacin, the N-desmethyl metabolite. The norfloxacin/pefloxacin ratios were 0 in mice, ca. 1 in rats and dogs, 1.6 in cynomolgus monkeys, and 2.3 in humans. The principal urinary compounds were unchanged drug in mice, pefloxacin glucuronide and pefloxacin N-oxide in rats and dogs, norfloxacin and pefloxacin in monkeys, and pefloxacin N-oxide and norfloxacin in humans. The urinary recovery of identified metabolites was 29.5% of the dose in mice, 37.8% in rats, 36.3% in dogs, 26.5% in monkeys, and 58.9% in humans. Biliary excretion occurred and was extensive in rats and dogs, mainly as a glucuronide conjugate of the drug. In rat and human bile, the main active compound was unchanged pefloxacin.

Adult↗
PubMed1983

High-performance liquid chromatography of pefloxacin and its main active metabolites in biological fluids.

We describe a high-performance liquid chromatographic (HPLC) method for the analysis of pefloxacin, a new antibacterial agent, in plasma and urine following administration of a therapeutic dose in humans. HPLC assay of pefloxacin and its two main active metabolites in urine is also described. The applicability of the methods to pharmacokinetic studies of pefloxacin in humans is demonstrated.

Anti-Infective Agents↗
PubMed1981

[A new synthetic antibacterial : 1-ethyl-6-fluoro-7-(4-methyl-1-piperazinyl)-4-oxo-1, 4-dihydroquinolin-3-carboxylic acid (1589 R.B.)].

The 1,4-dihydro-1-ethyl-6-fluoro-7-(4-methyl-1-piperazinyl)-4-oxoquinoline- 3-carboxylic acid (1589 R.B.) is a broad antibacterial agent active in experimental infections. The toxicological and pharmacokinetic profiles of the compound administered as methane sulfonic salt (1589 m R.B.), seem to suggest the possibility of using it in systemic infections.

Administration, Oral↗
PubMed1979

[Utilisation of pipemidic acid as antibiotic in patients with renal failure insufficiency. Kinetics of serum and urinary concentrations (author's transl)].

In 23 chronic renal patients serum and urinary concentrations of pipemidic acid were studied, the drug being given orally for 3 to 105 days. In 13 non-dialyzed patients, whose GFR varied from 4.5 to 36 ml/mn the dosage was 11.2 to 30 mg/kg/day. Maximum serum concentrations were comprised between 6 and 29 micrograms/ml. In 2 patients minor clinical side-effects indicated a maximum tolerance level of 25 micrograms/ml. Urinary concentrations remained elevated in spite of severe renal failure. In 10 hemodialyzed patients maximum predialysis levels varied from 5.6 to 28 micrograms/ml. No side-effects were noticed. The dialysance of pipemidic acid was high, due to a low molecular weight and to a binding to proteins which seems to be lower in uremics than in normal subjects. We conclude that pipemidic acid can be utilized in chronic renal patients, in taking advantage of low GFR's for obtaining serum bactericidal concentrations on susceptible organisms.

Administration, Oral↗