Drug-drug interaction between oxycodone and adjuvant analgesics in blood-brain barrier transport and antinociceptive effect

Yusuke Nakazawa, Takashi Okura, Keita Shimomura, Tetsuya Terasaki, Yoshiharu Deguchi

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


To examine possible blood-brain barrier (BBB) transport interactions between oxycodone and adjuvant analgesics, we firstly screened various candidates in vitro using [3H]pyrilamine, a substrate of the oxycodone transporter, as a probe drug. The uptake of [3H]pyrilamine by conditionally immortalized rat brain capillary endothelial cells (TR-BBB13) was inhibited by antidepressants (amitriptyline, imipramine, clomipramine, amoxapine, and fluvoxamine), antiarrhythmics (mexiletine, lidocaine, and flecainide), and ketamine. On the other hand, antiepileptics (carbamazepine, phenytoin, and clonazepam) and corticosteroids (dexamethasone and prednisolone) did not inhibit [3H]pyrilamine uptake, with the exception of sodium valproate. The uptake of oxycodone was significantly inhibited in a concentrationdependent manner by amitriptyline, fluvoxamine and mexiletine with Ki values of 13, 65, and 44 μM, respectively. These Ki values are 5-300 times greater than the human therapeutic plasma concentrations. Finally, we evaluated in vivo interaction between oxycodone and amitriptyline in mice. Antinociceptive effects of oxycodone were increased by coadministration of amitriptyline. The oxycodone concentrations in plasma and brain were not changed by coadministration of amitriptyline. Overall, the results suggest that several adjuvant analgesics may interact with the BBB transport of oxycodone at relatively high concentrations. However, it is unlikely that there would be any significant interaction at therapeutically or pharmacologically relevant concentrations.

Original languageEnglish
Pages (from-to)467-474
Number of pages8
JournalJournal of Pharmaceutical Sciences
Issue number1
Publication statusPublished - 2010 Jan
Externally publishedYes


  • Adjuvant analgesic
  • Blood-brain barrier
  • CNS
  • Distribution
  • Drug interactions
  • Oxycodone
  • Pyrilamine
  • Transporters

ASJC Scopus subject areas

  • Pharmaceutical Science


Dive into the research topics of 'Drug-drug interaction between oxycodone and adjuvant analgesics in blood-brain barrier transport and antinociceptive effect'. Together they form a unique fingerprint.

Cite this