Paper Title
Pharmacodynamic Interaction between Tamsulosin and Finasteride Treatment on Induced Benign Prostate Hyperplasia in Mice by using Choa-Talalay Method

Abstract
The study was designed to measure the efficacy and interaction type of tamsulosin with finasteride treatment on induced benign prostate hyperplasia (BPH) in mice. (BPH) was induced by subcutaneous injection of testosterone propionate (20 mg/kg) for 30 days. Eighty-five mice were divided into five groups. The first group (G1): twenty-five mice induced BPH treated with tamsulosin orally and divided into five equal subgroups with doses (0.017, 0.052, 0.087, 0. 123, and 0.158) mg/kg. The second group (G2): twenty-five mice induced BPH treated with finasteride orally and divided into five equal subgroups with doses (0.175, 0.527, 0.878, 1.23, and 1.580) mg/kg. third group (G3): twenty five mice induced BPH treated with combination of tamsulosin with finasteride orally, and divided into five equal subgroup with doses (0.0085, 0.0875), (0.026, 0.2635), (0.0435, 0.439) , (0.0615, 0.615) and ( 0.079 , 0.790 ) mg/kg respectively. The fourth group (G4): five mice induced BPH and treated with distilled water. In the fifth group (G5): five mice were not inducing BPH and without any treatment. The results showed a gradual significant increase in prostate weight % and prostate index % Inhibitions until reached saturation in the last two doses of tamsulosin, finasteride, and combination groups, the maximum effective dose of tamsulosin and finasteride were (0.156) and (1.495) mg/kg respectively. Moreover, the effective dose of combination tamsulosin and finasteride was computed (0.06876, 0.6876) mg/kg respectively as well as the type of interaction was synergistic and the value of the combination index was 0.046. This study concluded that the combination of tamsulosin with finasteride gave a synergistic effect in BPH treatment by minimizing the side effect of each drug by decreasing the dose of each one. Keywords - Tamsulosin, Finasteride, Effective Dose, BPH, Mice.