This paper presents a new solution that allows the doctors to know drug interactions, considering other affecting factors such as the patient's age, weight, physiological and pathological condition. This solution is characterized by being incremental, not only by enriching the database with drug interactions information, but also by its ability to conclude other interactions through a built-in expert system. The system concludes drugs interactions based on its active substrates and the potential interactions between them or between the drugs families. The system serves in three ways; it determines whether the patient illness is possibly due to the medications he is on. It alerts the doctor to the interaction of the newly prescribed medication with the patient’s medications, and to its influence on the patient’s physiological or pathological condition. Besides, it suggests alternative drugs when needed. The solution offers additional services such as binding between the brand name and the generic drug, and between drugs and diseases.