The availability of potent combination of antiretroviral regimens has resulted in a dramatic reduction in HIV-1 associated morbidity and mortality in the developed world. However, HIV infection and treatment has been associated with the development of insulin resistance, glucose intolerance and diabetes. The aim of the present study was to evaluate the effect of emtricitabine (antiHIV drug) on pharmacodynamic activity of sitagliptin (antidiabetic drug) in normal and diabetic rats with respect to insulin levels. Alloxan-induced diabetic model in rats has been used in this study. In normal rats and diabetic rats the levels of insulin were calculated at 3 hr and 8 hr. The insulin levels were found to be similar in the groups of sitagliptin control and after single dose and multiple dose treatment of emtricitabine in normal rats. The insulin levels of diabetic rats did not reduce significantly in single and multiple dose treatment of emtricitabine when compared to sitagliptin control. The results confirm the absence of pharmacodynamic interaction of sitagliptin with acute and chronic administration of emtricitabine.