Older people in hospital are more at risk of receiving an incorrect prescription.
A new survey from the Royal College of Surgeons has found the risk may be as high as 72%.
The survey found people over 65 are most affected.
Dr Frank Moriarty, from RCSI, says communication between GPs and hospital doctors is a key problem area.
Dr Moriarty said: "One of the key things that drives this is the poor channels of communication that exist between different parts of our health service."
"There is often silos of information and it can be quite difficult for a general practitioner or GP caring for a patient to try and understand why a prescription was started in hospital or why a prescription discontinued in hospital.
"This can put people at extra risk of medication issues."
- Digital Desk