Taking several different medicines may cause drug interactions, which may increase or decrease the action of a medicine to a point where it is harmful. Some OTC medicines, herbal remedies, dietary supplements and certain foods (such as grapefruit juice and milk) may significantly interact with other medicines. Because alcohol can enhance the effect of medicines that depress the central nervous system (such as sedatives, tranquillisers and strong painkillers), such drugs should not be mixed with alcohol.
Elderly people and patients with multiple medical problems often take several medicines and are therefore more likely than others to experience harmful interactions.
All medicine packages include a package leaflet, which provides important information on the medicine in question. The leaflet also mentions key interactions. To avoid harmful interactions, it is important to tell your doctor which medicines you are taking, including all prescription-free medicines, herbal remedies and dietary supplements. Pharmacy personnel can also offer advice on the compatibility of medicines.