title: Fluoxetine pretreatment effects pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, ECSTASY) in rat.
abstract: Fluoxetine has been shown to provide protection from MDMA induced long term neurotoxicity. The purpose of this investigation is to evaluate the pharmacokinetic drug interaction between MDMA and fluoxetine and also to determine the role of P-glycoprotein (P-gp) on mediating drug-drug interactions with MDMA. Bi-directional transport studies were conducted across MDCK-MDR1 and Caco-2 monolayers. MDMA brain and plasma levels were measured in P-gp deficient [mdr1a(-/-)] and normal [mdr1a(+/+)] mice after a 5 mg/kg i.p. dose of MDMA. Sprague-Dawley rats were pretreated with fluoxetine (4 days, 10 mg/kg, i.p.) or saline followed by MDMA (10 mg/kg, p.o.) and brain and plasma samples were collected over 10 h. MDMA and its active metabolite MDA were quantified using a HPLC method with fluorescence detection. In transport studies MDMA exhibited high permeability with essentially unpolarized transport. No significant difference in MDMA and MDA brain levels were seen in P-gp deficient versus normal mice. Pretreatment of rats with fluoxetine resulted in an increase in MDMA (1.4-fold) and MDA (1.5-fold) exposure in both brain and plasma. Elimination half-life was increased for MDMA (2.4 vs. 4.9 h) and MDA (1.8 vs. 8.2 h) with fluoxetine pretreatment. P-gp does not play a physiologically relevant role in absorption and distribution of MDMA, hence this transporter may not have a role in drug-drug interactions with MDMA. Fluoxetine pretreatment to provide protection from MDMA induced long term neurotoxicity decreases elimination of MDMA and MDA and may lead to enhanced risk of MDMA acute toxic effects. Overall, our results indicate that caution need to be practiced when recommending fluoxetine as an agent to provide protection from MDMA induced long term neurotoxicity.
authors.affiliation: Pharmacokinetics and Biopharmaceutics Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, 21201 Baltimore, Maryland, USA.
authors.forename: Vijay V
authors.initials: VV
authors.lastname: Upreti
authors.forename: Natalie D
authors.initials: ND
authors.lastname: Eddington
mesh_terms: D015104:3,4-Methylenedioxyamphetamine / Q000493:pharmacokinetics; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000502:physiology; D000429:Alcohol Oxidoreductases / Q000502:physiology; D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism; D018938:Caco-2 Cells; D019389:Cytochrome P-450 CYP2D6 / Q000502:physiology; D000072467:Cytochrome P450 Family 2; D004347:Drug Interactions; D005473:Fluoxetine / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051379:Mice; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005473:Fluoxetine; D015104:3,4-Methylenedioxyamphetamine; D000429:Alcohol Oxidoreductases; C504568:Cyp2d1 protein, rat; D019389:Cytochrome P-450 CYP2D6; D000072467:Cytochrome P450 Family 2; D018817:N-Methyl-3,4-methylenedioxyamphetamine