The digitalisation of healthcare processes is essential for minimising medical errors and increasing patient safety. The introduction of electronic systems in healthcare considerably improves the quality of healthcare services for patients by reducing the number of errors, increases the productivity among healthcare professionals by improving the communication between clinicians, and simplifies the digital tasks in healthcare environments. However, a significant source of errors in healthcare that affect patient safety is the lack of interoperability between healthcare information systems. To exploit all their benefits, electronic systems should be interoperable and able to exchange valuable information. The interoperability between systems is achieved using different healthcare information standards for storing and exchanging healthcare data. Two of the most hazardous processes in hospitals are prescribing medications and ordering medications form the pharmacy, which are mostly paper-based and therefore allow the possibility for medical errors. However, the number of possible medication errors can be decreased by a successful integration between the electronic prescribing system and electronic pharmacy system. This thesis gives an overview of the current situation regarding electronic prescribing systems and electronic pharmacy systems in the world, with a more prominent focus on Europe and the United Kingdom. It presents a proposal of the integration between electronic prescribing systems and electronic pharmacy systems for inpatient environment using healthcare the Fast Healthcare Interoperability Resources (FHIR) standard, and a proposal of mapping the data related to medications between the open Electronic Health Record (openEHR) and FHIR standard, which are used for interoperability, and for storing and exchanging healthcare data. Although the focus was on the integration between electronic systems in the United Kingdom, this proposal can be used for integration in all other countries willing to use FHIR standard. The benefits of integrated systems are presented, and the steps where medications errors can be reduced are identified. Additionally, challenges regarding the integration between the two systems that should be further tackled are presented.