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Abstract
Baclofen, β-(4-chlorophenyl)-γ-aminobutyric acid, holds a unique position in neuroscience, remaining the only U.S. Food and Drug Administration (FDA) approved GABAB agonist. While intended to be a more brain penetrant, i.e, ability to cross the blood-brain barrier (BBB), version of GABA (γ-aminobutyric acid) for the potential treatment of epilepsy, baclofen's highly efficacious muscle relaxant properties led to its approval, as a racemate, for the treatment of spasticity. Interestingly, baclofen received FDA approval before its receptor, GABAB, was discovered and its exact mechanism of action was known. In recent times, baclofen has a myriad of off-label uses, with the treatment for alcohol abuse and drug addiction garnering a great deal of attention. This Review aims to capture the >60 year legacy of baclofen by walking through the history, pharmacology, synthesis, drug metabolism, routes of administration, and societal impact of this Classic in chemical neuroscience.
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Affiliation(s)
- Caitlin N. Kent
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Charlotte Park
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Craig W. Lindsley
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
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Fan S, Ding Y, Chen X, Gao Y, Fu L, Li S, Li G. Palladium-Catalyzed C(sp2)–H Olefination of Free Primary and Secondary 2-Phenylethylamines: Access to Tetrahydroisoquinolines. J Org Chem 2019; 84:13003-13012. [DOI: 10.1021/acs.joc.9b01769] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Shuai Fan
- College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China
| | - Yongzheng Ding
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoxi Chen
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuzhen Gao
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
| | - Lei Fu
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
| | - Shangda Li
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
| | - Gang Li
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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Pálla T, Tóth G, Kraszni M, Mirzahosseini A, Noszál B. Population, basicity and partition of short-lived conformers. Characterization of baclofen and pregabalin, the biaxial, doubly rotating drug molecules. Eur J Pharm Sci 2018; 123:327-334. [DOI: 10.1016/j.ejps.2018.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/26/2018] [Accepted: 07/02/2018] [Indexed: 10/28/2022]
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Simon N, Franchitto N, Rolland B. Pharmacokinetic Studies of Baclofen Are Not Sufficient to Establish an Optimized Dosage for Management of Alcohol Disorder. Front Psychiatry 2018; 9:485. [PMID: 30349489 PMCID: PMC6186984 DOI: 10.3389/fpsyt.2018.00485] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/17/2018] [Indexed: 11/13/2022] Open
Abstract
Several clinical randomized trials have evaluated the interest of baclofen in patients with alcohol use disorder. Depending on the study design and the inclusion criteria, the results vary from enthusiastic to pessimistic. However, all researchers and practitioners agree that they observe a wide variability in the therapeutic responses. If some patients exhibit a clinical response at low doses, ~40 mg daily, others require doses higher than 300 mg. Before multiplying new other clinical trials, it is required to better understand the reason of this variability. Several mechanisms may be responsible for providing different effects with an identical daily dose. Especially, each pharmacokinetic step, absorption, distribution, metabolism, and elimination may lead to a different exposure after an identical dose. Absorption may imply a saturation process limiting the bioavailability (F) of baclofen in some patients. In such a situation, food, or drug-drug interaction can change the absorption rate of the drug modifying the maximum concentration (Cmax) and area under the curve (AUC). Distribution and brain penetration across the blood-brain barrier may depend of a specific transporter. These transporters are subject to genetic polymorphism and drug-drug interaction. Finally, elimination may be increased by a specific secretion pathway. This review describes all available pharmacokinetic data on these different pharmacokinetics steps aiming to identify the source of variability of baclofen in patients with alcohol use disorder.
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Affiliation(s)
- Nicolas Simon
- Aix Marseille Univ, INSERM, IRD, SESSTIM, Hop Sainte Marguerite, Service de Pharmacologie Clinique, CAP, Marseille, France
| | - Nicolas Franchitto
- Service d'addictologie, Centre Hospitalier Universitaire de Toulouse, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1027, Université Paul Sabatier, Toulouse, France
| | - Benjamin Rolland
- Service Universitaire d'Addictologie, Pôle UP-MOPHA, CH Le Vinatier, Bron, France.,Univ Lyon, Inserm U1028, CNRS UMR5292, UCBL, CRNL, Bron, France
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Riaz S, Schumacher A, Sivagurunathan S, Van Der Meer M, Ito R. Ventral, but not dorsal, hippocampus inactivation impairs reward memory expression and retrieval in contexts defined by proximal cues. Hippocampus 2017; 27:822-836. [PMID: 28449268 DOI: 10.1002/hipo.22734] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 04/05/2017] [Accepted: 04/12/2017] [Indexed: 12/12/2022]
Abstract
The hippocampus (HPC) has been widely implicated in the contextual control of appetitive and aversive conditioning. However, whole hippocampal lesions do not invariably impair all forms of contextual processing, as in the case of complex biconditional context discrimination, leading to contention over the exact nature of the contribution of the HPC in contextual processing. Moreover, the increasingly well-established functional dissociation between the dorsal (dHPC) and ventral (vHPC) subregions of the HPC has been largely overlooked in the existing literature on hippocampal-based contextual memory processing in appetitively motivated tasks. Thus, the present study sought to investigate the individual roles of the dHPC and the vHPC in contextual biconditional discrimination (CBD) performance and memory retrieval. To this end, we examined the effects of transient post-acquisition pharmacological inactivation (using a combination of GABAA and GABAB receptor agonists muscimol and baclofen) of functionally distinct subregions of the HPC (CA1/CA3 subfields of the dHPC and vHPC) on CBD memory retrieval. Additional behavioral assays including novelty preference, light-dark box and locomotor activity test were also performed to confirm that the respective sites of inactivation were functionally silent. We observed robust deficits in CBD performance and memory retrieval following inactivation of the vHPC, but not the dHPC. Our data provides novel insight into the differential roles of the ventral and dorsal HPC in reward contextual processing, under conditions in which the context is defined by proximal cues.
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Affiliation(s)
- Sadia Riaz
- Department of Psychology (Scarborough), University of Toronto, Toronto, Canada
| | - Anett Schumacher
- Department of Psychology (Scarborough), University of Toronto, Toronto, Canada
| | | | | | - Rutsuko Ito
- Department of Psychology (Scarborough), University of Toronto, Toronto, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
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Clinical Relevance of Pharmacological and Physiological Data in Intrathecal Baclofen Therapy. Arch Phys Med Rehabil 2014; 95:2199-206. [DOI: 10.1016/j.apmr.2014.04.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 03/01/2014] [Accepted: 04/21/2014] [Indexed: 11/22/2022]
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Kim TH, Shin S, Shin JC, Choi JH, Seo WS, Park GY, Kwon DR, Yoo SD, Lee AR, Joo SH, Min BS, Yoo WY, Shin BS. Liquid chromatography–tandem mass spectrometry determination of baclofen in various biological samples and application to a pharmacokinetic study. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 938:43-50. [DOI: 10.1016/j.jchromb.2013.08.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 07/26/2013] [Accepted: 08/21/2013] [Indexed: 11/27/2022]
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Baclofen ester and carbamate prodrug candidates: A simultaneous chromatographic assay, resolution optimized with DryLab®. J Pharm Biomed Anal 2011; 56:569-76. [DOI: 10.1016/j.jpba.2011.06.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 06/08/2011] [Accepted: 06/26/2011] [Indexed: 11/18/2022]
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van der Plas AA, Marinus J, Eldabe S, Buchser E, van Hilten JJ. The Lack of Efficacy of Different Infusion Rates of Intrathecal Baclofen in Complex Regional Pain Syndrome: A Randomized, Double-Blind, Crossover Study. PAIN MEDICINE 2011; 12:459-65. [DOI: 10.1111/j.1526-4637.2011.01065.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Sub-region specific contribution of the ventral hippocampus to drug context-induced reinstatement of cocaine-seeking behavior in rats. Neuroscience 2010; 171:830-9. [PMID: 20870011 DOI: 10.1016/j.neuroscience.2010.09.032] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 08/30/2010] [Accepted: 09/17/2010] [Indexed: 12/16/2022]
Abstract
The ventral hippocampus (VH) plays critical roles in cue-induced and cocaine-primed reinstatement of cocaine seeking [Rogers JL, See RE (2007) Neurobiol Learn Mem 87:688-692]. Subregions of the VH make distinct projections to elements of the brain relapse circuitry that mediate drug context-induced reinstatement. Thus, the VH may also critically contribute to this form of cocaine seeking in a subregion-specific manner. Accordingly, this study evaluated the hypothesis that functional inactivation of the ventral hippocampus proper (VHp)-but not of the dentate gyrus (DG)-impairs cocaine seeking elicited by re-exposure to a drug-paired environmental context. Rats were trained to lever press for un-signaled i.v. cocaine infusions (0.15 mg/infusion) in a distinct environmental context (cocaine-paired context) followed by extinction training in a distinctly different context (extinction context). Subsequently, cocaine-seeking behavior (i.e., non-reinforced active lever responding) was assessed in either the previously cocaine-paired context or the extinction context. Rats received bilateral microinfusions of the GABA agonist cocktail, baclofen+muscimol (BM: 1.0/.01 mM), or vehicle into the VHp, DG, or the posterior dorsal hippocampus (pDH; extra-VH control) immediately before each test session. Exposure to the previously cocaine-paired context, but not the extinction context, reinstated extinguished cocaine-seeking behavior following vehicle pretreatment. BM pretreatment administered into the VHp, but not the DG or pDH, significantly attenuated drug context-induced cocaine seeking. These results indicate that the VH contributes to drug context-induced cocaine seeking in a subregion-specific manner, with the functional integrity of the VHp being necessary for memory or motivational aspects of drug-paired environmental stimuli that sustain stimulus control over goal-directed behavior.
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Froestl W. Chemistry and Pharmacology of GABAB Receptor Ligands. GABABRECEPTOR PHARMACOLOGY - A TRIBUTE TO NORMAN BOWERY 2010; 58:19-62. [DOI: 10.1016/s1054-3589(10)58002-5] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Nucleus accumbens shell and core involvement in drug context-induced reinstatement of cocaine seeking in rats. Psychopharmacology (Berl) 2008; 200:545-56. [PMID: 18597075 PMCID: PMC2613506 DOI: 10.1007/s00213-008-1234-4] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 06/09/2008] [Indexed: 12/28/2022]
Abstract
RATIONALE The nucleus accumbens (NAC) is a functionally heterogeneous brain region with respect to its involvement in cocaine-seeking behavior triggered by drug-associated explicit conditioned stimuli, foot shock stress, or cocaine itself in the reinstatement animal model of drug relapse. However, it is not known whether the NAC or its subregions are critical for reinstatement of cocaine-seeking behavior produced by re-exposure to a previously cocaine-paired environmental context. OBJECTIVES The present study was designed to evaluate potentially unique contributions of the NAC core and shell to this behavior. MATERIALS AND METHODS Rats were trained to lever press for unsignaled cocaine infusions (0.15 mg/infusion, intravenous) in a distinct environmental context. Lever responding was then extinguished in a distinctly different environmental context (extinction context) during a minimum of seven daily training sessions. Subsequently, using a counterbalanced testing design, rats were re-exposed to the cocaine-paired context or the extinction context while cocaine seeking (i.e., responding on the previously cocaine-reinforced lever) was assessed. Before each test session, neural activity was inhibited selectively in the NAC core or shell using bilateral microinfusions of the gamma-aminobutyric acid agonists, baclofen and muscimol (0/0 or 1.0/0.1 mM; 0.3 microl per hemisphere). RESULTS Neural inactivation of the NAC shell or core attenuated responding in the cocaine context and, interestingly, increased responding in the extinction context. Control experiments indicated no effects on general activity or food-reinforced instrumental behavior. CONCLUSIONS These findings suggest that both subregions of the NAC may promote context-induced reinstatement by facilitating drug context-induced motivation for cocaine and context discrimination.
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Yeh CH, Prasad Korivi R, Cheng CH. Regioselective Synthesis of γ-Amino Esters, Nitriles, Sulfones, and Pyrrolidinones by Nickel-Catalyzed Reductive Coupling of Aldimines and Activated Alkenes. Angew Chem Int Ed Engl 2008; 47:4892-5. [DOI: 10.1002/anie.200800825] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Yeh CH, Prasad Korivi R, Cheng CH. Regioselective Synthesis of γ-Amino Esters, Nitriles, Sulfones, and Pyrrolidinones by Nickel-Catalyzed Reductive Coupling of Aldimines and Activated Alkenes. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200800825] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Fuchs RA, Eaddy JL, Su ZI, Bell GH. Interactions of the basolateral amygdala with the dorsal hippocampus and dorsomedial prefrontal cortex regulate drug context-induced reinstatement of cocaine-seeking in rats. Eur J Neurosci 2007; 26:487-98. [PMID: 17650119 DOI: 10.1111/j.1460-9568.2007.05674.x] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The basolateral amygdala (BLA), dorsomedial prefrontal cortex (dmPFC) and dorsal hippocampus (DH) are critical elements of the neurocircuitry of drug context-induced reinstatement of cocaine-seeking; however, little is known about functional interactions between these brain regions. The present study tested the hypothesis that serial information processing by the BLA and dmPFC mediates drug context-induced cocaine-seeking, whereas the BLA and DH independently control this behaviour. Rats were trained to self-administer cocaine in a distinct environment (cocaine-paired context) followed by extinction training in a different environment (extinction context). On the test days, rats received unilateral microinfusions of baclofen + muscimol or of vehicle into the BLA and either the contralateral or ipsilateral dmPFC or DH. Cocaine-seeking behaviour (i.e. nonreinforced presses on the cocaine-associated lever) was then assessed in the cocaine-paired and extinction contexts. Following vehicle pretreatment, exposure to the cocaine-paired context reinstated extinguished cocaine-seeking behaviour. BLA-dmPFC asymmetrical inactivation attenuated cocaine-seeking behaviour relative to vehicle treatment; however, this impairment equaled that produced by ipsilateral BLA-dmPFC inactivation. Furthermore, unilateral inactivation of the BLA or dmPFC did not alter this behaviour. BLA-DH asymmetrical inactivation selectively attenuated cocaine-seeking behaviour relative to vehicle treatment whereas ipsilateral or unilateral inactivation of the BLA and DH did not alter this behaviour. These findings indicate that the BLA and DH exhibit sequential information processing within the relapse circuitry. In contrast, interactions between the BLA and dmPFC are more complex and include parallel loops of information processing and/or necessary interhemispheric input from the dmPFC to the BLA, probably in addition to direct intrahemispheric interactions.
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Affiliation(s)
- Rita A Fuchs
- Department of Psychology, University of North Carolina, CB#3270, Chapel Hill, NC 27599-3270, USA.
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Cao F, Guo JX, Ping QN, Liao ZG. Prodrugs of scutellarin: ethyl, benzyl and N,N-diethylglycolamide ester synthesis, physicochemical properties, intestinal metabolism and oral bioavailability in the rats. Eur J Pharm Sci 2006; 29:385-93. [PMID: 16997537 DOI: 10.1016/j.ejps.2006.07.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 07/04/2006] [Accepted: 07/28/2006] [Indexed: 11/24/2022]
Abstract
In an effort to enhance the oral bioavailability of scutellarin, ethyl, benzyl and N,N-diethylglycolamide ester of scutellarin were synthesized. The hydrolysis of the prodrugs follows first-order kinetics in aqueous solution, and produced a V-shaped pH profile. The N,N-diethylglycolamide ester is highly susceptible to enzymatic hydrolysis in human plasma (t(1/2) approximately 7 min) with a high stability in aqueous solution (t(1/2) approximately 16 day, pH 4.2). Compared with the solubility of scutellarin, the solubility of glycolamide ester was about ten times in pH 4.0 buffer, and about thirty five times in water. Its apparent partition coefficient increased significantly from -2.56 to 1.48. Glycolamide ester of scutellarin was chosen to investigate the intestinal metabolism and in vivo bioavailability. Degradation studies in the intestinal tract content and homogenates indicated intestinal metabolism before absorption was a crucial obstacle for the prodrug. N,N-Diethylglycolamide ester can be protected from the degradation in the intestinal lumen by an emulsion. A significant increase in the plasma AUC and C(max) of the prodrug emulsion was observed in rats, compared with that of the scutellarin-cyclodextrin complex (P<0.01). The emulsion of N,N-diethylglycolamide ester produces a 1.58-fold enhancement in apparent bioavailability and 1.4-fold increase in the absolute bioavailability compared to the scutallarin-cyclodextrin complex.
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Affiliation(s)
- Feng Cao
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
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Hilgendorf C, Spahn-Langguth H, Rhedin M, Regårdh CG, Löwenadler B, Langguth P. Selective Downregulation of the MDR1 Gene Product in Caco-2 Cells by Stable Transfection To Prove Its Relevance in Secretory Drug Transport. Mol Pharm 2005; 2:64-73. [PMID: 15804179 DOI: 10.1021/mp049931y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Considerable interest is focused on overcoming multidrug resistance (MDR) in cancer chemotherapy. The in vitro experiments to characterize P-glycoprotein's (P-gp) function and to decrease its effects have led to a variety of strategies such as addition of competitors or supplementation of the medium with oligonucleotides complementary to the 5'-end of the MDR1-mRNA. For the Caco-2 cell line, an in vitro model for absorption screening, expressing multiple transporters including P-gp, which pumps substances back into the apical solution, P-gp activity might mask other relevant transport proteins' activity. The objective of the present study was to construct a Caco-2 subline with reduced P-gp expression level. Caco-2 cells were transfected by electroporation with two different mammalian expression vectors, and the obtained subclones were investigated at RNA (Northern blotting, RT-PCR), protein (FACS analysis), and functional (transport studies) levels for reduction in P-gp expression. Northern blotting showed that the levels of transcription of the inserted gene were different among the several clones, but those results did not completely correlate with the FACS analysis for P-gp expression. The clones with the strongest reduction in P-gp expression detected by the FACS analysis also showed the lowest secretory fluxes of the P-gp substrate talinolol in transport studies. Repetition of FACS analysis after 7 and 24 months on 20 to 30 passage older subclones still showed reduction in P-gp expression and indicated that they are stably transfected. The new cell lines constructed in the present study provide the possibility to perform in vitro absorption studies in a cell system composed of differentiated enterocytes growing as a monolayer like the normal Caco-2 cell line but with a lower down to almost lacking expression of P-gp.
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Affiliation(s)
- Constanze Hilgendorf
- School of Pharmacy, Martin Luther University, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany
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El Ela AA, Härtter S, Schmitt U, Hiemke C, Spahn-Langguth H, Langguth P. Identification of P-glycoprotein substrates and inhibitors among psychoactive compounds--implications for pharmacokinetics of selected substrates. J Pharm Pharmacol 2004; 56:967-75. [PMID: 15285840 DOI: 10.1211/0022357043969] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The pharmacokinetics of antipsychotic drugs has become an integral part in understanding their pharmacodynamic activity and clinical effects. In addition to metabolism aspects, carrier-mediated transport, particularly secretion by ABC transporters, has been discussed as potentially relevant for this group of therapeutics. In this study, the psychoactive compounds perphenazine, flupentixol, domperidone, desmethyl clozapine, haloperidol, fluphenazine, fluvoxamine, olanzapine, levomepromazine, perazine, desmethyl perazine, clozapine, quetiapine and amisulpride were characterized in terms of P-glycoprotein (P-gp) affinity and transport. Experimental methods involved a radioligand displacement assay with [3H]talinolol as radioligand and transport--as well as transport inhibition--studies of the P-gp substrate [3H]talinolol across Caco-2 cell monolayers. In addition, the physicochemical descriptors log P and deltalog P were determined to test potential correlations between transporter affinity and lipophilicity parameters. All of the tested antipsychotics showed affinity to P-gp albeit their IC50 values (concentration of competitor that displaced 50% of the bound radioligand) differed by a factor exceeding 1000, when compared using the transport inhibition assay. From the group of P-gp substrates, amisulpride and fluphenazine were selected for in-vivo drug-drug interaction studies in rats to demonstrate the in-vivo relevance of the in-vitro findings. Compounds were administered by intraperitoneal injection either alone or in combination with 50 mg kg(-1) ciclosporin. The concentration versus time profiles for both drugs were followed in serum as well as in brain tissues. Significant differences between the treatments with the antipsychotic alone versus the combination of antipsychotic with ciclosporin were found for amisulpride. The distribution of amisulpride to the brain was increased and systemic serum levels were likewise increased indicating decreased systemic clearance for the combination regimen. For fluphenazine, systemic levels with and without co-administration of ciclosporin were comparable while higher brain-to-serum concentration ratios were found after co-administration of ciclosporin. The findings are explained on the basis of the limited contribution of P-gp-mediated transport to the elimination of fluphenazine and to a direct effect with respect to its distribution into the brain.
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Affiliation(s)
- Amal Abou El Ela
- Institute of Pharmacy, Biopharmaceutics and Pharmaceutical Technology, University of Mainz, Germany
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