If you take medication at home, even if it has not been prescribed by your GP, take it with you in the original packaging when you are admitted to the hospital and talk to your doctor about whether or not you can continue to take it during your stay.
Even if you take vitamin supplements or a contraceptive pill, for instance, it is best to tell your doctor.
Some medicines cannot be taken together. This is why your doctor will sometimes suggest adapting the medication you take at home temporarily. Never take medication during your stay without the consent of your doctor, even if it seems harmless. Always check that the medication you are given is actually intended for you.