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Biomedical subjects

E Albengres

Publications and source records attributed to E Albengres.

At least 73 records · Page 4Linked to original sources
PubMed1981

Serum protein binding of valproic acid in healthy subjects and in patients with liver disease.

The binding parameters of valproic acid (VPA) to human serum albumin (HSA) were determined by equilibrium dialysis and computed using non-linear regression. However unclassic, it was observed that the binding parameters of VPA varied according to the concentration of the HSA solutions used. At 580 microM HSA, VPA is bound to two classes of binding sites with the association constants K1 = 56000 M(-1) and K2 = 750 M(-1), and their respective numbers of binding sites n1 = 2 and n2 = 5. Free serum fraction of VPA is significantly increased by 500, 1000 and 1500 microM palmitate, 250 microM clofibrate, 320 microM phenylbutazone, or 360 microM salicylate. In any case, the increase of the VPA serum free fraction is highly correlated with the inhibitor concentration. On the other hand, the free serum fraction of warfarin is increased by 600 microM VPA (100 micrograms/ml). In patients with liver disease, the variations of the free serum fraction of VPA are correlated to the albumin and to the bilirubin concentrations. Serum binding of VPA is significantly decreased in the two groups of patients as compared with the control group.

Binding, Competitive↗
PubMed1981

Protein-bound and free plasma phenytoin during pregnancy.

In a clinical study using low doses of phenytoin as an ovulation inducer, the plasma levels and the binding percentages of this drug and the plasma level of its main metabolite, p-hydroxyphenytoin, were monitored. The results show that during pregnancy, plasma levels of both remain stabile and low as compared with those observed in epilepsy treatment. This could be one explanation for the absence of teratogenic effects observed in this and other studies using phenytoin for the same therapeutic aim.

Blood Proteins↗
PubMed1980

[Hypolipidaemic agents (author's transl)].

Since clofibrate was discovered, a number of compounds have been made available for the treatment of hyperlipoproteinaemias. Their principal pharmacological and therapeutic properties are summarized in this paper. Other compounds are now under pre-clinical or clinical studies, including probucol which is reviewed in this issue.

Animals↗
PubMed1980

Effect of tienilic acid (Diflurex) on the binding of warfarin 14C to human plasma proteins.

Tienilic acid (Diflurex), a new diuretic with a chemical structure close to that of ethacrynic acid, displaces significant amounts of warfarin from 2 g/l human albumin in vitro by a competitive mechanism. When physiologic concentrations of human albumin are used, or with human plasma there is no such interaction. Because excessive hypoprothrombinaemia and haemorrhage were reported in vivo when tienilic acid was added to oral coumarin anticoagulant therapy, it is advised to use another diuretic if necessary.

Aged↗
PubMed1979

Methodological aspects of the evaluation of the binding of drugs to plasma and tissue proteins.

This paper describes the methodological aspects of the evaluation of the binding of drugs to plasma and tissue proteins. The relevance of the procedures employed to certain problems in clinical-pharmacology as well as the role of plasma binding in drug distribution and pharmacokinetics are discussed. The possibly important role of plasma protein binding of some drugs is emphasized. The incidence of plasma binding on drug distribution and pharmacokinetics are developed and the possible incidence of pathological states on drug plasma binding are considered.

Animals↗
PubMed1977

[Modification during treatment of the rate of acetylation of isoniazide clinically or biologically detectable hepatic damage (author's transl)].

The rate of acetylation of isoniazid is usually constant in a given subject. The authors report here a case where despite an adjusted initial dose there was a decrease in the rate of acetylation during treatment with INH-rifampicin and ethambutol, without hepatic involvement but accompanied by retrobulbar optic neuritis. The role of ethambutol and/or an overdose of isoniazid are discussed. The technique for its estimation is also described.

Acetylation↗
PubMedDate not supplied

A re-evaluation of the HSA-piroxicam interaction.

Piroxicam binding to HSA was studied using equilibrium dialysis and fluorescence methods. It was shown that this drug, like its analogs isoxicam and tenoxicam, binds to the apazone locus (site I area) and to a lesser extent to the diazepam site (site II). The piroxicam binding to HSA can be modulated by various specific ligands--apazone, warfarin, diazepam, ibuprofen--and these drug interactions have to be considered not only as potential displacement from the HSA binding sites but also in terms of induced allosteric effects.

Apazone↗
PubMedDate not supplied

Plasma protein binding and erythrocyte partitioning of nicardipine in vitro.

Using isotope techniques, equilibrium dialysis, and incubation experiments, we characterized the binding of nicardipine to isolated plasma proteins, human serum, blood cells, and platelets. Nicardipine was mainly bound to lipoproteins, orosomucoïd, albumin, and erythrocytes in human blood. Nicardipine, pindolol, and imipramine were found to share the same site on orosomucoïd. The determinants of nicardipine binding to lipoproteins were triglycerides, phospholipids, and cholesterol ester. Nicardipine partitioned into erythrocytes, showing a constant ratio of distribution between the intra- and extracellular compartments. Nicardipine partitioned less to erythrocytes when increasing amounts of binding plasma proteins were present in the extracellular compartment. In human blood, 12 to 18% of total nicardipine was present in erythrocytes. The overall binding of nicardipine in serum varied from 98 to 99.5% and correlated with serum orosomucoïd and serum lipid concentrations.

Blood Proteins↗
PubMedDate not supplied

A case of destructive polyarthropathy in a 17-year-old youth following pefloxacin treatment.

Joint and muscle pain have been reported with quinolones; however, arthropathies induced by quinolones do not result in erosive changes in humans, although such changes have occurred in animal studies. We report an unusual case of destructive polyarthropathy in a 17-year-old boy after treatment with pefloxacin 800 mg/day for 3 months. Pefloxacin may have accentuated the cartilage damage in this case, even if an underlying joint disease could not be excluded.

Adolescent↗
PubMedDate not supplied

[Pharmacologic and biologic basis of drug allergies].

Drugs are able to activate the immune system, which may generate hypersensitivity states in individuals. This article first deals with the critical processes that are involved in drug sensitizations: what are the specific features of drugs as immunogens; how are drugs recognized as non-self by activated immune cells; what is the spontaneous outcome of an immune response to drugs in individuals; does a genetic predisposition regulate the immune response to drug antigens; how much are biotransformation processes involved in the immunogenicity of drugs? The second part is mostly devoted to the biological investigation of drug sensitizations: what are we looking for and why; are all the available methods equally suitable for routine diagnosis; what are the major methological problems that we have to deal with in investigating patients who have presented with symptoms which are clinically suspected to be of immuno-allergic origin?

Animals↗
PubMedDate not supplied

[The risk of falling due to benzodiazepine administration, alone or in combination, in elderly subjects].

Benzodiazepines are well tolerated by young adults whereas in elderly people they are less safe and globally induce more central nervous system side-effects and falls. Falls result from a decrease of vigilance and an alteration of postural reflex. This latter includes the reception of sensory information and central integration modulated mainly by dopaminergic D2 receptors and motor stimulation. Benzodiazepines act simultaneously on the three stages, decreasing their efficacy. The risk increases when certain other drugs are coprescribed, especially synergistic drugs such as another psycholeptic drug, an aminoside or a centrally active antihypertensive drug. Thus their co-prescription with a benzodiazepine increases the risk of falls. The pharmacokinetic parameters of benzodiazepines may be modified or remain constant during ageing. The choice of molecules whose parameters do not vary seems advisable. Whatever the selected benzodiazepine, it is obvious that it must be administered at the lowest possible dose, this dose being increased only if necessary, the overall prescription being time limited.

Accidental Falls↗
PubMedDate not supplied

[The pharmacologic basis of pain treatment].

The treatment of chronic pain uses drugs from different pharmacological classes. Analgesics are the common basis of these treatments. Peripheral analgesics (or minor analgesics such as paracetamol) and non-steroidal anti-inflammatory drugs are used for moderate pain (grade I of WHO). Major analgesics, opioids, are used for more severe pain (grades II and III). When pain can be related to a precise cause or location, more specific drugs may be used. This is done in migraine, facial pain, muscular spasms, dental pain, local inflammation. Chronic pain of grades II and III is treated with opioids. According to the severity, agents of different powers are used: partial agonists, full agonists of receptors OP3 (mu) and OP2 (kappa). According to other pathological signs linked to pain, coanalgesic drugs may be used in association: psychotropic drugs, either psycholeptic drugs which act synergistically with analgesics and bring their own effects, anxiolytic and/or neuroleptic, or anti-depressants which inhibit the depression state that may be associated with pain. Corticosteroids are also very useful for the numerous effects they induce: inhibition of the inflammation process, CNS stimulation, analgesics in medullary, or plexus compressions and in elevations of intracranial hypertension. Moreover their metabolic effects may be useful in cachectic states. The pharmacological treatment of chronic pain of grades II and III poses the problem of chronic administration of increasing doses of opioids and of their coprescription, of acquired tolerance, of dependence and of toxicity induced by drug accumulation.

Analgesics↗