The present study aimed to determine the relationship between the lipid-lowering effect generated by the alpha-blocking drugs doxazosin and terazosin with the activity of the enzyme catalase in a mice model of hyperlipidemia. 30 male albino mice were used, which were equally distributed in 5 groups. The blank and hyperlipidemic control groups received 0.5% carboxymethylcellulose (CMC) orally in doses of 10 ml / kg. The drugs doxazosin and terazosin were dissolved in CMC, and then administered orally in doses of 1 mg / 100 g to problem I and problem II groups, respectively; and the drug atorvastatin dissolved in CMC administered orally in doses of 10 mg / Kg to the standard group. The induction of hyperlipidemia was carried out on the ninth day of treatment by administering Triton in a single dose of 400 mg / Kg intraperitoneally to the control, standard, problem I and problem II groups. After 24 hours of triton administration, blood samples were taken to determine the cholesterol, triglyceride and catalase activity values. Analysis of Variance, Nonlinear Regression and Principal Component Analysis were used, with a significance level of p <0.05. In problem I (doxazosin), problem II (terazosin) and standard (atorvastatin) groups with respect to the hyperlipidemic control group, a significant decrease (p <0.05) in cholesterol and triglyceride values was observed. When evaluating the specific activity of catalase, it was found that there is a significant increase (p <0.05) in enzyme activity in problem I, problem II and standard groups compared to the hyperlipidemic control group. A non-linear relationship was observed between cholesterol and triglyceride levels with catalase activity. The results of this study show an inverse non-linear relationship between the lipid-lowering effect of doxazosin and terazosin with the enzymatic activity of catalase in the model tested.