Effect of Secnidazole on the Disposition Kinetics of Diminazene Aceturate in Healthy Dogs

Background and Objective: Secnidazole (SEC) has been successfully combined with DA in the treatment of canine trypanosomosis without relapse parasitemia. However, the nature of the interaction between SEC and DA is not known. This study evaluated the influence of SEC on the disposition kinetics of DA in a healthy dog. Materials and Methods: Twelve dogs of both sexes were assigned to 2 groups A and B (n = 6). Group A was pre-treated with SEC (100 mg kg^–1) 30 min before administration of DA (3.5 mg kg^–1) IM. Group B received DA (3.5 mg kg^–1) alone IM. Zero-time blood sample was obtained 15 min before DA administration and blood samples were obtained from each at 0.25, 0.5, 1, 2, 3, 6, 9, 12, 24, 36, 48, 60 and 72 hrs post-administration. Serum samples harvested were analysed for DA using the spectrophotometric method. Results: A double compartment model with a biphasic elimination best described the behaviour of DA in the two groups. Pre-treatment with SEC significantly (p<0.05) altered the C_max,elimination rate constant, elimination half-life, total body clearance and area under the concentration-time curve of DA. Conclusion: Results concluded that the observed effects of SEC on the pharmacokinetic profile of DA may impact positively the efficacy of DA in trypanosome infected dogs.