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Biomedical subjects

S Erill

Publications and source records attributed to S Erill.

At least 19 recordsLinked to original sources
PubMed1990

Effects of cefotaxime on the serum protein binding of sulfisoxazole.

The possible acylating effects of cefotaxime on sulfisoxazole binding to serum proteins were evaluated in vitro in samples of human sera incubated with 50-1000 micrograms ml-1 cefotaxime at 37 degrees for 1 h and then dialyzed against saline. This incubation resulted in concentration-related increases in the free fraction of sulfisoxazole (+25 per cent, +30 per cent, and +45 per cent, with 250, 500, and 1000 micrograms ml-1 cefotaxime, respectively). Sulfisoxazole binding was also studied in samples of sera from patients given prophylactic cefotaxime (3 g d-1, IV) following elective surgery. Sulfisoxazole free fraction increased from 7.6 +/- 0.7 per cent in samples obtained before starting treatment to 9.2 +/- 0.8 per cent 24 h thereafter, and to 10.4 +/- 1.0 per cent after 5 days of treatment, but this difference was not statistically significant. A Scatchard plot of pooled samples showed a reduction in overall affinity (from 2.38 X 10(-4) M to 1.77 X 10(-4) M) without changes in the number of binding sites. The effects of cefotaxime on sulfisoxazole binding and kinetics were also studied experimentally in the rabbit. Treatment with 30 mg kg-1 cefotaxime t.i.d. for 2 days increased the unbound fraction of sulfisoxazole in vivo, from 17.2 +/- 2.9 per cent to 27.3 +/- 3.6 per cent (p less than 0.02). Treatment with high doses of cefotaxime, and perhaps other 3-acetoxymethylcephalosporins, may result in changes in the serum protein binding of some acidic drugs.

Animals↗
PubMed1990

Decrease in penbutolol central response as a cause of changes in its serum protein binding.

Penbutolol is a beta-adrenoceptor antagonist that is extensively bound to alpha 1-acid glycoprotein (alpha 1-AGP), a protein that increases in inflammatory diseases thereby binding more drug in such conditions. Changes in serum binding can lead to modifications in the pharmacokinetics and pharmacodynamics of a drug, therefore, the central effect (as the anticonvulsant response) and brain uptake of penbutolol given intravenously to mice with experimental inflammation have been measured. A significant decrease of the central effect of penbutolol and its brain uptake was seen in diseased when compared with control animals (P less than 0.01). A parallel decrease in free fraction of penbutolol in diseased vs normal animals was detected. These results suggest that there is an increase in serum binding of basic drugs related to increments in alpha 1-AGP concentration, which reduces their central pharmacological effect.

Animals↗
PubMed1987

Serum protein binding of sulfisoxazole and diazepam in patients with chronic obstructive pulmonary disease.

Binding of two acidic drugs, sulfisoxazole and diazepam, to serum proteins has been investigated in patients with chronic obstructive pulmonary disease and in a control group of healthy volunteers. Marked increases in the free fraction of both drugs in serum were detected in patients (14.5 +/- 0.8% versus 6.1 +/- 0.3% in the case of sulfisoxazole, and 5.8 +/- 0.5% versus 3.2 +/- 0.0% in the case of diazepam). Decreased serum albumin concentration appeared to play a role in the defective binding of sulfisoxazole, although when this factor was corrected, some correlation between serum binding of sulfisoxazole and PaO2 values was detected. Other factors have to be considered to explain the decreased binding of diazepam in the serum of patients with chronic obstructive pulmonary disease.

Aged↗
PubMed1986

Differential effects of valproic acid on the serum protein binding of lorazepam and diazepam.

Valproic acid and free fatty acids have been shown to displace diazepam from its plasma binding sites both in vitro and in vivo. Since lorazepam exhibits a substantial degree of binding, but differs from other benzodiazepines in that no increase in its free fraction in serum is observed when free fatty acids are raised, the effect of valproate on the serum protein binding of diazepam and lorazepam was assessed. Sodium valproate produced a marked increase in the free fraction of diazepam, but practically no effect on the percentage of free lorazepam.

Blood Proteins↗
PubMed1986

Serum protein binding of model acidic drugs in smokers and non-smokers.

The serum protein binding of sulfisoxazole (sulfafurazole, INN) and diazepam, drugs that bind to the two main binding sites for acidic drugs on albumin, has been studied in young smokers and non-smokers. No differences between the two groups could be detected with regard to the serum protein binding of either drug. Thiocyanate, present in relatively large amounts in the serum of smokers, does not seem to affect the drug-binding properties of serum proteins.

Adolescent↗
PubMed1985

Morphine-induced skin wheals: a possible model for the study of histamine release.

We evaluated the ability of morphine to release histamine when injected intradermally in man. Mathematic analysis of the dose-response (wheal) relationship suggested that two different effects were involved. The effect of low doses of morphine (0.05 to 1 microgram) was clearly antagonized by naloxone (0.4 or 1.2 mg im 30 minutes before), whereas the effect of higher doses (5 to 50 micrograms) was not modified. The median effective doses of morphine (ED50) for the low dose range effect were 0.07 +/- 0.01 and 0.08 +/- 0.01 microgram before naloxone and 0.14 +/- 0.02 and 0.15 +/- 0.03 microgram after 0.4 and 1.2 mg doses, respectively. Astemizole (45 mg po 30 minutes before) and oxatomide (60 mg po 120 minutes before) produced similar inhibition of histamine-induced wheals, but there were clear differences in their effects on wheals elicited by morphine. Morphine ED50 values for the low dose range effect rose from 0.09 +/- 0.01 to 0.20 +/- 0.01 microgram after astemizole and from 0.08 +/- 0.01 to 0.46 +/- 0.04 microgram after oxatomide. Opiate receptors may be involved in some of the effects produced by morphine injection in the human skin, but morphine-induced wheals seem to offer a suitable model for the evaluation of agents capable of inhibiting histamine release in man.

Adult↗
PubMed1979

Image of systemic antimicrobial agents as perceived by physicians in a 900 bed hospital.

A survey among hospital staff physicians was conducted in order to evaluate their attitudes towards systemic antimicrobial agents. Direct questions about the value of different agents and choice within pairs of antimicrobial drugs, stating the reasons for the preference, were included in the questionnaire used. Gentamicin, penicillin G and ampicillin were the most popular antibiotics among respondents. On the other hand, ampicillin, penicillin G, sulfonamides, tetracycline and aminoglycosides were the agents perceived as most often associated with side-effects. Low toxicity, bactericidal effect, diffusion in the body and familiarity with the drug were acknowledged as the most important attributes in choice of a systemic antimicrobial agent, but a broad spectrum of antibacterial activity appeared as a major determinant in the choice of these drugs when physicians were asked to select one substance from members of several pairs listed. The results suggest that certain important misconceptions may have played a substantial role in the prescribing habits of the physicians surveyed.

Anti-Bacterial Agents↗
PubMed1979

Etomidate and plasma esterase activity in man and experimental animals.

No hydrolysis of etomidate in plasma in vitro was detected in samples from man, horse, cow, sheep, guinea pig or white rabbit. Brown rabbits showed a moderate degree of hydrolysis and it was marked in plasma from Wistar rats. In this species, a single enzyme, an alliesterase, participated in the hydrolysis in plasma. Etomidate did not interfere with the hydrolysis of procaine by plasma pseudocholinesterase in man.

Animals↗
PubMed1979

Plasma protein binding of salicylate and quinidine in patients with multiple myeloma.

The plasma protein binding of salicylate, a representative acidic drug, and of quinidine, a representative basic drug, has been studied in patients with multiple myeloma, a disease characterized by a profound alteration of the plasma protein pattern. Abnormal binding of salicylate was detected only in patients with high values of circulating abnormal protein. Plasma protein binding of quinidine was not altered in any of the patients studied.

Adult↗
PubMed1978

Metabolism of procainamide in patients with chronic heart failure, chronic respiratory failure and chronic renal failure.

Fractional hydrolysis and acetylation of procainamide, acetylation of procainamide-derived p-aminobenzoic acid and plasma hydrolysis of procaine were studied in 20 patients with chronic heart failure (CHF), 20 patients with chronic respiratory insufficiency (CRI) and 20 patients with chronic renal failure (RF). The results were compared with those obtained in a group of 20 normal volunteers. Hydrolysis of procainamide and procaine were reduced in patients with CHF and CRI, but not in patients with RF. Moreover, more marked decreases in procainamide and procaine hydrolysis were seen in subgroups with secondary hepatic dysfunction. The diminution of hydrolysis of procainamide was not paralleled by changes in acetylation of procainamide or p-aminobenzoic acid. It is concluded that in patients with hepatic involvement secondary to advanced CHF or CRI, hepatic and plasmatic hydrolysis activity is decreased to a degree equivalent to primary liver failure.

Acetylation↗
PubMed1977

Protein binding of salicylate and quinidine in plasma from patients with renal failure, chronic liver disease and chronic respiratory insufficiency.

The plasma protein binding of a representative acidic drug, salicylate, and a representative basic drug, quinidine, has been studied in patients with several diseases that are sometimes associated with uraemia or a change in serum albumin level. Decreased plasma protein binding of salicylate was observed in plasma from patients with uraemia and liver disease. Low albumin levels in these patients could only account inpart for the decreased binding. On the other hand, salicylate binding to plasma proteins appeared to be increased in patients with hypoxia. Decreased plasma protein binding of quinidine was observed in some patients with uraemia and in the majority of patients with liver disease.

Adult↗
PubMed1977

Metabolism of procainamide and p-aminobenzoic acid in patients with chronic liver disease.

Procainamide acetylation and hydrolysis, procainamide-derived p-amino-benzoic acid acetylation, and plasma hydrolysis of procaine were studied in normal volunteers and in 20 patients with chronic liver disease, Impairment of procainamide acetylation was evident in the patients, but no correlations were demonstrable between the degree of impairment and the severity of the disease. On the other hand, procainamide hydroylsis was diminished in liver disease, and as indicated by depression of serum albumin levels and plasma prothrombin activity this alteration did correlate with the degree of impairment of liver function. Procaine hydrolysis in plasma was also affected, the mean in vitro plasma half-life being prolonged in the patients with liver disease and correlating with the degree of hepatic impairment. A correlation of procainamide hydrolysis with procaine hydrolysis was also observed. Finally, acetylation of procainamide-derived p-aminobenzoic acid appeared to increase in patients with liver disease, the degree of acetylation increasing with decreasing procainamide hydrolysis capacity.

4-Aminobenzoic Acid↗