In-Vivo Evaluation of the Antiplasmodial Effect of Amodiaquine and Amodiaquine-Promethazine Combination in Plasmodium berghei Infected Mice

Purpose: Antihistamine H1 receptor antagonists like promethazine (PR) are capable of reversing resistance of Plasmodium falciparum to some antimalarials drugs like amodiaquine (AQ). This work was carried out to evaluate the antiplasmodial activity of amodiaquine and amodiaquine-promethazine combination in Plasmodium berghei infected mice. Methods: Groups of mice (112) infected with chloroquine resistant Plasmodium berghei ANKA strain were treated with 10mg/kg amodiaquine alone for three days or 10mg/kg AQ combined with graded doses (10, 20, 30, 40, 50 mg/kg) of PR twice daily over 7 days). Thin blood films were used to assess parasitemia for 60 days. Results: Therapeutic effect of AQ combined with graded doses of PR was dose-dependent with the combination of AQ and the highest concentration of PR (50mg/kg) having the shortest parasite clearance time (PCT) (1.28± 0.49) days and longest recrudescence time (RT) of (17.33±11.86 days) compare to AQ alone. The mean PCT was significantly reduced as doses of PR increased up to 50mg/kg (P<0.01). The survival rates (93.8% and 50%) in the group of animals receiving 50mg/kg of PR plus AQ and AQ alone, respectively were significantly different (P<0.01). Conclusion: Promethazine potentiates the therapeutic effects of amodiaquine against the chloroquine resistant P. berghei infection in male albino mice.