The results from the recent study by Glintborg et al.  are not surprising (lack of significant drug-drug interactions in patients recently discharged from hospital). It is expected that clinically important interactions are identified while the patient is in hospital, with one of the offending agents stopped or changed to a safer alternative before discharge. Furthermore, any clinically important interactions are likely to be identified by the patient’s community pharmacist, who alerts the general practitioner and prevents possible harm before the prescription is even dispensed.
Naunton, M., Duyvendak, M., Peterson, G. M., & Brouwers, J. R. J. B. (2006). Comments on Glintborg et al.'s drug-drug interactions study (EJCP 2005; 61: 675-681). European Journal of Clinical Pharmacology, 62(2), 159-160. https://doi.org/10.1007/s00228-005-0074-y