The Systematic Tool to Reduce Inappropriate Prescribing (STRIP) is a clinical intervention method crafted to deal with polypharmacy problems which are incurred by the concurrent use of multiple drugs. STRIP has been proven to be effective and is included in the Dutch national guideline for polypharmacy. To boost the usage of STRIP in clinical practices, a web application called the STRIP Assistant (STRIPA) was developed and further evaluated as user-friendly, efficient and effective by Dutch physicians. STRIPA has now evolved into a software tool that supports a large multinational randomized clinical trial (RCT). However, in order to successfully implement and use the application in such an RCT, several issues, including multilingual support, clinical data security, data accessibil-ity and consistency, need to be addressed. In this paper, we present an overhauled STRIPA prototype with an lightweight data integration component that supports multinational implementations, ensures data consistency across countries, and maintains data accessibility and security. The component in-cludes a high-level information architecture, data models redesigned to generalize data entities from all countries, and the ETL processes that integrate diverse data sources and transfer data between databases. Technical features of the application are tested during the implementation, and it also is about to be evaluated empirically as part of the RCT across four European countries.