Effective communication regarding the use of medications in hospital environments is a process that contributes to patient safety. Despite its importance, written communication about the medication use process in medical records remains insufficiently investigated. To describe the documentation in medical records regarding the medication use process by pharmacists, physicians and nurses on admission, during the hospital stay, and at hospital discharge. A retrospective cross-sectional chart review study was carried out in medical records of patients admitted to a teaching hospital in Northeast Brazil. The study considered all patients admitted between December 2016 and February 2017, aged 18 or older and hospitalised for at least 48hours. Clinical notes made by pharmacists, physicians and nurses were examined at three transition points of care. Data were collected using a questionnaire relating to the use of medications prior to hospital admission, changes in the prescribed medications during the hospital stay and discharge, as well as prescription non-conformities. Communication failures between the three healthcare professional groups were analysed and classified. The study was authorised by the Hospital's Board of Directors and approved by the Research Ethics Committee of the Federal University of Sergipe. This study included 202 medical records of patients with a mean age of 51.48 (SD 6.42, range: 19-97) years. There was no record of a patient or relative interview on allergies and adverse drug reactions in 54 (26.8%) physician notes, 44 (21.9%) nursing notes, and 9 (25.0%) pharmacist notes. Moreover, 1,588 changes in prescriptions were identified during data collection, and 1,198 (75.4%) of these were unjustified. Medication-related information in medical records was incomplete and inconsistent in the clinical notes of the three studied professions, especially in pharmacists' documentation. Future studies should focus on investigating the consequences of interprofessional communication in patient care.