(Rac)-Modipafant (UK-74505) (10 mg/kg; p.o.; twice a day until day 10) prevents Severe Dengue Infection. (Rac)-Modipafant exhibits highly selective, time-dependent inhibition of PAF-induced aggregation of rabbit washed platelets (IC50=26.3 and 1.12 nM after 0.25 and 60 min preincubation, respectively). (Rac)-Modipafant (5-20 mg/kg; p.o.) dose-dependently inhibits the Zymosan -induced articular hyperalgesia.