title: Interaction of white and pink grapefruit juice with acetaminophen (paracetamol) in vivo in mice.
abstract: Grapefruit juice increases bioavailability of a number of drugs because of inhibition of the P-glycoprotein pump and inhibition of intestinal cytochrome P450 3A4 enzyme. However, interaction between acetaminophen (also known as paracetamol in many parts of the world) and grapefruit juice has never been reported. The interaction of grapefruit juice with acetaminophen was examined in an in vivo mouse model. BALB/c mice were fed 200 microL of white grapefruit juice or pink grapefruit juice by oral gavage (three mice in each group) followed by oral delivery of 10, 50, or 100 mg/kg acetaminophen 1 hour later. Blood was withdrawn from the retro-orbital venous plexus at 1 hour and 2 hours after feeding with acetaminophen. The concentrations of acetaminophen in sera of mice were determined by fluorescence polarization immunoassay. White grapefruit juice increased concentrations of acetaminophen in mice both 1 hour and 2 hours after feeding compared to controls. In contrast, pink grapefruit juice increased acetaminophen concentrations 2 hours after feeding compared to controls. Because acetaminophen is almost completely absorbed these effects seems to be related to increased elimination half-life of acetaminophen because of interaction with grapefruit juice.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Texas Health Sciences Center at Houston, Houston, Texas 77030, USA. Amitava.Dasgupta@uth.tmc.edu
authors.forename: Amitava
authors.initials: A
authors.lastname: Dasgupta
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Reyes
authors.forename: Semyon A
authors.initials: SA
authors.lastname: Risin
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Actor
mesh_terms: D000082:Acetaminophen / Q000493:pharmacokinetics*; D000818:Animals; D001628:Beverages; D032083:Citrus paradisi; D016231:Fluorescence Polarization Immunoassay; D018565:Food-Drug Interactions; D006207:Half-Life; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D028321:Plant Preparations / Q000494:pharmacology*
chemical_list: D028321:Plant Preparations; D000082:Acetaminophen