I am living in Spain - in general, chemists here will fill a prescription from another EU country and often will based on the empty box, as long as it has the patients name on a sticker and the person has their ID with them. However, its not a given - I have encountered chemists who have looked at me blankly when I have tried it. You would also want to check whether the brand name of the drug is the same in Ireland and in Spain - some are quite different. I wouldn´t advise your friend to go to Spain without any of her medication but if she is thinking of bringing her prescription over on the of change it will get filled and will be cheaper, then go for it! I get my MIL her cholesterol drugs here - 47 in Ireland, 2.74 in Spain! However, since the reduction in chemist fees in Ireland, some drugs are actualy cheaper in Ire than Spain, notably anti-depressants.