Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Cytochrom P450 ; Pharmakokinetik ; Selek- tive Serotonin-Wiederaufnahmehemmer ; Genetischer Polymorphismus ; Interaktionen ; Key words Cytochrome P450 ; Pharmacokinetics ; Selective serotonin reuptake inhibitors ; Gemetic polymorphism ; Drug interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Nearly all psychotropic drugs are metabolized by hepatic cytochrome P450-enzymes. In humans, there are 5 isoenzymes involved in this process. The activity of these enzymes can be modulated by a number of commonly used drugs, yielding potentially hazardous interactions. Most of the recently introduced selective serotonin reuptake inhibitors are potent inhibitors of cytochrome P450 enzymes. Thus, the plasma concentrations of tricyclic antidepressants or clozapine might be elevated into toxic levels. In contrast, carbamazepine induces most of the isoenzymes. This potentiates the elimination of tricyclics and antipsychotics and might cause a serious risk for the reccurence of depressive or psychotic symptoms. Moreover, 5–10% of the population are slow metabolizers of CYP2D6. This group is prone to increased adverse effects of moderately dosed medication. This review systematically points out the reported or predicted pharmacokinetic drug interactions in psychopharmacology focussing on clinical significance.
    Notes: Zusammenfassung Fast alle Psychopharmaka werden durch die Cytochrom-P450-Enzyme der Leber abgebaut. Beim Menschen sind mindestens 5 Isoenzyme für diesen Prozeß verantwortlich. Diese können in jeweils unterschiedlichem Umfang durch eine Reihe von Medikamenten in ihrer Aktivität beeinflußt werden. Bei gleichzeitiger Anwendung mehrerer Substanzen kann es durch diesen Mechanismus zu Wechselwirkungen mit potentiell ernsten Folgen kommen. So inhibieren die meisten der selektiven Serotonin-Wiederaufnahmehemmer P450-Enzyme und können dadurch z.B. die Plasmakonzentrationen von trizyklischen Antidepressiva in toxische Bereiche heben. Carbamazepin hingegen induziert viele der Isoenzyme; durch den schnelleren Abbau von Trizyklika oder Neuroleptika können zu geringe Konzentrationen dieser Substanzen resultieren und Rezidive von Depressionen oder Psychosen ausgelöst werden. Überdies weisen aufgrund eines genetischen Polymorphismus 5–10% der Bevölkerung eine geringere Aktivität des Isoenzyms CYP2D6 auf und reagieren deshalb mit verstärkten Nebenwirkungen auf übliche Dosierungen vieler Pharmaka. In dieser Übersichtsarbeit wird systematisch auf pharmakokinetische Interaktionen im Bereich der Psychopharmakologie hingewiesen, die bisher berichtet wurden oder zu befürchten sind. Besonderer Wert wird dabei auf die klinische Signifikanz solcher Ergebnisse gelegt.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0843
    Keywords: Liposomes ; Alkylphosphocholine ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Hexadecylphosphocholine (HePC) shows remarkable antineoplastic efficacy in Sprague-Dawley rats bearing methylnitrosourea-induced mammary carcinoma. Unfortunately, this is accompanied by detrimental side effects that include gastrointestinal damage, body weight loss, and thrombophlebitis after i.v. injection, which has precluded the use of the HePC in humans, where nausea and vomiting can occur at noneffective dose levels. We have developed small unilamellar vesicles (SUVs) composed of HePC, cholesterol, and 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol, which can be given p. o. and i.v. In contrast to the free drug, the toxicity of liposomal HePC is shown to be greatly reduced, and there is no risk of thrombophlebitis. Single administration of equimolar HePC doses results in differing pharmacokinetic values for free HePC (p. o.) and HePC-SUVs (p. o., i.v.).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-1335
    Keywords: Antineoplastic efficacy ; Melphalan ; Diazoxide ; Insulin ; Mammary carcinoma ; Sprague-Dawley rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The anticancer activity of melphalan andN-(2-chloroethyl)-N-nitrosocarbamoyl-ω-lysine (CNC-ω-Lys), was compared in the autochthonous, methylnitrosourea-induced mammary carcinoma of the Sprague-Dawley rat. In addition, the influence on the therapeutic efficacy of the combination with diazoxide, causing a mild, reversible diabetes, and with insulin was investigated. The comparison of melphalan and CNC-ω-Lys clearly showed the superiority of melphalan. Both compounds displayed a significant tumour inhibition in their medium and the highest dosages in comparison to the untreated control. The combination with diazoxide resulted for almost all groups in an increased tumour inhibition. Only the lowest dose of CNC-ω-Lys + diazoxide did not reduce the tumour volume significantly versus the control group. The combination with insulin, however, resulted in a loss of tumour inhibition compared to the effect of the cytotoxic drug alone, although in these groups, too, a significant decrease of tumour volumes versus controls could be observed. Mortality was within tolerable limits (〈20%) through the treatment period for all experimental groups. Median lifespans were increased in all therapy groups, but no additional benefit could be observed in the combination treatment groups.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 14 (1988), S. 236-237 
    ISSN: 1432-1238
    Keywords: Hemofiltration ; Flecainide ; Atrial fibrillation ; Pharmacokinetics ; Renal failure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Flecainide, a new antiarrhythmic drug, has been shown not no be removed to a significant extent by hemodialysis or peritoneal dialysis, in spite of a high renal clerance. Its systemic and hemofiltrate clearances, measured in a patient under continuous hemofiltration, were 402 and 19.7 ml/min respectively. The clearance ratio of less than 5% makes the contribution of hemofiltration to the elimination of flecainide clinically negligeable.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-1335
    Keywords: Vitamins A, E ; Semisynthetic fatty diet ; Methylnitrosourea ; Mammary carcinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Prolonged supplementation of vitamins A and E (2500 IU and 11.3 IU/rat daily) in 10.3% and 21.6% fatty diets administered to methylnitrosourea-induced Sprague-Dawley rats caused alterations in plasma and liver levels of both vitamins as well as of the total lipids. Liver vitamin A levels increased steadily (more than four-fold) until termination of the experiment, whereas plasma vitamin A levels only showed a minor increase at the end of the study in comparison to rats fed a standard diet. Liver vitamin E levels initially showed no difference from those of rats treated with a standard diet, and were decreased at the end of the experiment, whereas the respective plasma levels were increased throughout the study, only showing a decrease relative to initial values at termination of the experiment. Plasma total lipids increased with age and following supplementation of the vitamins in the high-fat diet, whereas liver total lipids were influenced less by aging than by the fat and vitamin contents of the respective diets. The observed alterations were, however, not related to significant chemopreventive activity of the vitamins A and E contained in high-fat diets.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of cancer research and clinical oncology 116 (1990), S. 538-549 
    ISSN: 1432-1335
    Keywords: Androgen-linked alkylating agents ; Methylnitrosourea ; Mammary carcinoma ; Anticancer activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This article gives a comprehensive survey on the anticancer activity of nitrosoureas linked to steroidal androgens in methylnitrosourea (MMU)-induced rat mammary carcinoma. cis-Androsterone, testosterone, 19-nortestosterone and 5-α-dihydrotestosterone were used as carrier hormones and were linked to various cytotoxic N-[N′-(2-chloroethyl)-N′-nitrosocarbamoyl] (CNC)-aminoacids and to N-(2-hydroxyethyl)-N′-(2-chloroethyl)-N′-nitrosourea hemisuccinate (HECNU-hemisuccinate). In the MNU-model used esters of dihydrotestosterone (DHT) invariably were more active and less toxic than those of testosterone, nortestosterone and cis-androsterone. Within the DHT esters of CNC-aminoacids those of CNC-glycine, CNC-methionine and CNC-alanine showed the highest antineoplastic activities and superiority compared with equimolar dosages of their unlinked mixtures. Additionally, CNC-alanine-DHT ester had the highest therapeutic ratio of all agents investigated. HECNU-hemisuccinate-DHT ester, on the other hand, achieved even higher antitumor activity at the optimal dose but had a narrower therapeutic ratio. No obvious correlation between antineoplastic efficacy and receptor binding affinity could be demonstrated, but, to be active, a conjugate apparently had to have some receptor binding affinity for both androgen and progesterone receptors. The results obtained indicate that linking antineoplastic agents to transport molecules with affinity to steroid receptors is a highly promising approach to obtain drugs with specific activity in steroid receptor containing tumors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...