Evaluation of the Efficacy of a Combination of Artemether and Diminazene Aceturate Therapy in Experimental Trypanosoma brucei Infection in Rats

Abstract

This study evaluated the efficacy of a combination of artemether and diminazene aceturate therapy in experimental Trypanosoma
brucei infection in rats. Thirty five male albino rats used for the study were randomly assigned to seven groups of five rats each
as follows: Group A- infected and treated with diminazene aceturate (DA) at 7.0 mg/kg body weight (bw), intramuscular (IM)
once on day 7 post-infection (pi); Group B – infected and treated with artemether (ART) at 3.2 mg/kg bw IM on day 7pi and 1.6
mg/kg bw IM on days 8,9,10 and 11pi; Groups C,D and E, – infected and treated with DA at 7.0 mg/kg bw IM, 3.5 mg/kg bw
IM, and 1.75 mg/kg bw IM respectively, once on day 7pi and ART at 3.2 mg/kg bw IM on day 7pi plus 1.6 mg/kg bw on days
8,9,10 and 11pi; Group F –infected, untreated and Group G – uninfected, untreated. Onset of parasitaemia (OP), level of
parasitaemia (LOP), clearance of parasites post treatment, mortality post infection, relapse of parasitaemia post clearance, rectal
temperature, and body weight, were determined at specified intervals during the 70-day experimental period. Results showed
that there were no significant (p > 0.05) variations in the OP and LOP between the infected groups. Trypanosomes were cleared
from the blood of rats in group A, C, D, and E after treatment. All the rats in groups B and F were dead by day 14pi. The infection
relapsed in groups C and E. It was concluded that a combination of DA (3.5 mg/kg bw once) and ART (3.2 mg/kg bw on day
1 of treatment and 1.6 mg/kg bw for 4 consecutive days) exhibited efficacy comparable to the standard dose of DA at 7 mg/kg
in the treatment of trypanosome brucei in rats and could thus possibly constitute an effective treatment regimen to reduce the
dose of DA and avoid toxicity.

Keywords: Efficacy; Combination therapy; Artemether; Diminazene aceturate; Trypanosoma brucei