The possibility that non-sedating antihistamines could elicit sedation in mice due to drug-induced inhibition of brain PgP was evaluated by measuring the ability of desloratadine alone or in combination with verapamil to cause ataxia in mice. Also, the concentrations of desloratadine in plasma and in brain homogenates were measured by liquid chromatography-mass spectrometry. Relative to methylcellulose (control) treatment, verapamil plus desloratadine decreased rotarod performance of mice. Plasma concentrations of desloratadine appeared comparable in the mice treated with either desloratadine or verapamil plus desloratadine, however the rate of decline of desloratadine from brain tissue was slower in mice treated with verapamil plus desloratadine compared to mice treated with desloratadine only. These data suggest that inhibition of brain PgP can convert desloratadine to a sedating antihistamine in mice.
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http://dx.doi.org/10.2174/187231207779814391 | DOI Listing |
J Hazard Mater
May 2024
Division for Marine and Environmental Research, Ruder Boskovic Institute, Bijenicka c. 54, 10000 Zagreb, Croatia. Electronic address:
Uptake and elimination kinetics, bioconcentration factors (BCFs), and metabolic transformation of 20 different pharmaceutically active compounds (PhACs), covering a wide range of therapeutic categories and physico-chemical properties, were studied using zebrafish (Danio rerio). The fish were exposed to the mixture of the selected PhACs at environmentally relevant concentrations similar to 10 µg L. The experiments were performed in semi-static conditions and comprised a 7-day uptake period followed by a 7-day depuration period.
View Article and Find Full Text PDFAnticancer Res
July 2019
School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
Background/aim: Previously, we showed that KBV20C cancer cells highly resistant to antimitotic drugs were sensitized by co-treatment with a repositioned drug fluphenazine.
Materials And Methods: Considering that fluphenazine plays a role as a histamine receptor antagonist, we investigated low doses of 21 other histamine receptor antagonists (lidocaine, cimetidine, chlorpromazine, diphenhydramine, promethazine, ranitidine, famotidine, clemastine, chlorpheniramine, desloratadine, loratadine, cyproheptadine, azelastine, brompheniramine, carbinoxamine, fexofenadine, hydroxyzine, levocetirizine, meclizine, nizatidine, and pemirolast) to identify repositioned drugs for their sensitizing effects on antimitotic drug-resistant KBV20C cells at relatively low doses.
Results: Co-treatment with loratadine, and with azelastine highly sensitized KBV20C cells to vincristine treatment.
Drug Metab Pharmacokinet
October 2015
Drug Metabolism and Pharmacokinetics Japan, Eisai Product Creation Systems, Eisai Co., Ltd.
In central nervous system drug discovery, cerebrospinal fluid (CSF) drug concentration (C(CSF)) has been widely used as a surrogate for unbound brain concentrations (C(u,brain)). However, previous rodent studies demonstrated that when drugs undergo active efflux by transporters, such as P-glycoprotein (P-gp), at the blood-brain barrier, the C(CSF) overestimates the corresponding C(u,brain). To investigate the utility of C(CSF) as a surrogate for interstitial fluid (ISF) concentration (C(ISF)) in nonhuman primates, this study simultaneously determined the C(CSF) and C(ISF) of 12 compounds, including P-gp substrates, under steady-state conditions in cynomolgus monkeys using intracerebral microdialysis coupled with cisternal CSF sampling.
View Article and Find Full Text PDFDrug Metab Lett
January 2007
Department of Pharmacology, University of Toledo College of Pharmacy, Toledo, Ohio, USA.
The possibility that non-sedating antihistamines could elicit sedation in mice due to drug-induced inhibition of brain PgP was evaluated by measuring the ability of desloratadine alone or in combination with verapamil to cause ataxia in mice. Also, the concentrations of desloratadine in plasma and in brain homogenates were measured by liquid chromatography-mass spectrometry. Relative to methylcellulose (control) treatment, verapamil plus desloratadine decreased rotarod performance of mice.
View Article and Find Full Text PDFDrug Metab Dispos
May 2004
Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 Japan.
We investigated influx and efflux transporters involved in blood-brain barrier transport of the nonsedative H1-antagonist epinastine. The basal-to-apical transport of [14C]epinastine was markedly higher than that in the opposite direction in LLC-GA5-COL150 cells stably transfected with human multidrug resistance (MDR)1 gene. The brain-to-plasma concentration ratio of [14C]epinastine in mdr1a/b(-/-) mice was 3.
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