Fluoxetine potentiates chloroquine and mefloquine effect on multidrug-resistant Plasmodium falciparum in vitro

Research output: Contribution to journalLetter


Fluoxetine (FLX), a P-glycoprotein inhibitor with antimalarial activity, is promising candidate for reversing chloroquine/mefloquine (CQ/MQ) resistance. The Dd2 strain of CQ- and MQ-resistant Plasmodium falciparum was synchronized and assayed with various concentrations of CQ/MQ individually and in combination with FLX or verapamil (VPL). Our results indicated the 50% inhibitory concentration values of CQ and MQ were greatly lowered when FLX was used simultaneously. Isobolograms indicated that CQ-FLX combinations are more synergistic (mean fractional inhibitory concentration [FIC] index 0.55) than MQ-FLX (mean FIC index 0.64), and their synergistic effect was better than or at par with CQ-VPL (mean FIC index 0.88) and MQ-VPL (mean FIC index 0.60) combinations. We conclude that the FLX potentiates the CQ and MQ response on multidrug-resistant P. falciparum at clinically achievable concentrations.


  • Mohd Fadzli Mustaffa Khairul
  • Hooi Min Tan Grahn
  • Jen Hou Low
  • Che Husin Che Nasriyyah
  • Azahri Noor A'shikin
  • Mohd Nor Norazmi
  • Manickam Ravichandran
  • Suraparaju Sivachandra Raju
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cell and Molecular Biology
Original languageEnglish
Pages (from-to)329-331
JournalJapanese Journal of Infectious Diseases
Issue number5
Publication statusPublished - 2006
Publication categoryResearch