Designing supply chain networks is one of the concerns of pharmaceutical distribution companies, since these companies are forced to expand or redesign their branch locations due to national regulations or fierce competition. In this research, using an integrated approach, the issue of pharmaceutical supply chain design for distribution companies has been addressed in such a way that all costs including opening new branches, distribution of goods and inventory along with the requirements related to existing legal regulations have been presented in the form of a mathematical model. Specifically, in this research, the parameters affecting inventory cost of the entire company at the level of the supply chain were considered. Further, due to the complexity of the resulting model, a hybrid approach including clustering of demand points and meta-heuristic algorithms was used to solve it. In order to evaluate effectiveness, the model was applied to the data of Sina Pakhsh Gen Company. Finally, in several scenarios, optimal location of new branches, optimal level of inventory, and optimal distribution plan were investigated. Results show that an integrated approach to supply chain design will lead to reduction in total costs.