Essentially you should check the regulations for the destination country and also any countries you stay in during transit (ie: you leave the transit/departure area of the airport) with the relevant embassy (see list of embassies in the UK).
Different countries have different regulations about what type of medicine and maximum quantity that you can bring into the country.
Some medicines that are available over the counter in the UK may be subject to stricter regulation in other countries (and vice versa).
Medicines should be kept in their original packaging – prescription medicine will also be labelled by the pharmacy, including your name, and this should also be retained as proof that the medicine is for personal use.
You should also take a copy of the prescription with you. Dr Fox can provide a copy of a patient’s prescription on request for travel/import purposes.