Aging is a progressive, gradual and constant in which there is a reduction in the structure and function of organs and organ systems. As the population ages, there will always be an increasing proportion of chronic diseases. This is the main reason for prescribing an increasing number of drugs. Chronic patient care and healthcare are complex processes which in most cases require the use of multiple medications at the same time. Unfortunately, that leads to the development of unwanted side as well as an increase in hospitalization and mortality in the elderly. Advances in medicine like discovering new drugs and the application of various new treatments, such as new diagnostic tests and therapeutic options, have enabled earlier recognition of disease and more advanced treatment for chronic diseases. But we should always pay attention to drug interactions, which can occur when we simultaneously use multiple drugs on patients, and it is important to adhere to the basic rule: when administering two drugs at the same time, drugs of known interactions and side effects should always be used and doses adjusted to this combination. A big role in the proper use of drugs and recognizing possible side effects is played by the nurse. She spends the longest time with the patient and with the help of communication with patients, patient behaviour and personal knowledge are very important in active nursing diagnoses, if she is able to respond in a timely manner and record all procedures. Changes in nursing documentation is the key to nursing work and allows us to see the changes from the very beginning of patient hospitalization. It is very important to monitor the patient's health condition and after discharge from the hospital, give him appropriate instructions, as well as his family members in case of a patient who can’t independently take care of themselves, and inform the doctor about any new changes.