title: Pharmacokinetics of quinacrine efflux from mouse brain via the P-glycoprotein efflux transporter.
abstract: The lipophilic cationic compound quinacrine has been used as an antimalarial drug for over 75 years but its pharmacokinetic profile is limited. Here, we report on the pharmacokinetic properties of quinacrine in mice. Following an oral dose of 40 mg/kg/day for 30 days, quinacrine concentration in the brain of wild-type mice was maintained at a concentration of ∼1 µM. As a substrate of the P-glycoprotein (P-gp) efflux transporter, quinacrine is actively exported from the brain, preventing its accumulation to levels that may show efficacy in some disease models. In the brains of P-gp-deficient Mdr1(0/0) mice, we found quinacrine reached concentrations of ∼80 µM without any signs of acute toxicity. Additionally, we examined the distribution and metabolism of quinacrine in the wild-type and Mdr1(0/0) brains. In wild-type mice, the co-administration of cyclosporin A, a known P-gp inhibitor, resulted in a 6-fold increase in the accumulation of quinacrine in the brain. Our findings argue that the inhibition of the P-gp efflux transporter should improve the poor pharmacokinetic properties of quinacrine in the CNS.
authors: Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, USA.
authors: Misol
authors: M
authors: Ahn
authors: Sina
authors: S
authors: Ghaemmaghami
authors: Yong
authors: Y
authors: Huang
authors: Puay-Wah
authors: PW
authors: Phuan
authors: Barnaby C H
authors: BC
authors: May
authors: Kurt
authors: K
authors: Giles
authors: Stephen J
authors: SJ
authors: DeArmond
authors: Stanley B
authors: SB
authors: Prusiner
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000493:pharmacokinetics*; D001921:Brain / Q000378:metabolism*; D016572:Cyclosporine / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011796:Quinacrine / Q000493:pharmacokinetics*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D004791:Enzyme Inhibitors; D009419:Nerve Tissue Proteins; D016572:Cyclosporine; D011796:Quinacrine