title: No inhibitory effect on P-glycoprotein function at blood-brain barrier by clinical dose of clarithromycin: a human PET study with [¹¹C]verapamil.
abstract: OBJECTIVE
  To investigate the effects of the clinical dose of clarithromycin, a substrate of P-glycoprotein (P-gp), on P-gp function using positron emission tomography (PET) with [11C]verapamil.
  
  
  METHODS
  Two PET scanning with [11C]verapamil were performed before and after administration of 400 mg/day of clarithromycin on each of four healthy male subjects. The rate constant of transfer from plasma to brain (K1) was estimated by integration plot method.
  
  
  RESULTS
  K1 values of [11C]verapamil before administration of clarithromycin were 0.042-0.070 mL/cm3/min (0.054 ± 0.012) and those after administration were 0.037-0.066 mL/cm3/min (0.055 ± 0.013). No significant change in K1 values of [11C]verapamil was observed between before and after administration of clarithromycin (P = 0.85).
  
  
  CONCLUSIONS
  K1 values of [11C]verapamil were not changed by clinical dose administration of clarithromycin, suggesting that a clinical dose of clarithromycin does not affect P-gp function at the blood-brain barrier.
authors.affiliation: Molecular Neuroimaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Arakawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.forename: Masaki
authors.initials: M
authors.lastname: Okumura
authors.forename: Takuya
authors.initials: T
authors.lastname: Morimoto
authors.forename: Chie
authors.initials: C
authors.lastname: Seki
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Takahashi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takano
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Suhara
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects; D001812:Blood-Brain Barrier / Q000187:drug effects* / Q000378:metabolism*; D002250:Carbon Radioisotopes; D017291:Clarithromycin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography; D014700:Verapamil / Q000378:metabolism; D055815:Young Adult
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000900:Anti-Bacterial Agents; D002250:Carbon Radioisotopes; D014700:Verapamil; D017291:Clarithromycin