If you are travelling abroad rules vary with regard to what medicines you are allowed to bring with you. You need to check each country that you are visiting, this is especially important in relation to controlled drugs. The NHS website provides more information on this as well as some advice if you are flying with your medicine http://www.nhs.uk/chq/Pages/1074.aspx?CategoryID=70&SubCategoryID=175
Most airlines allow mobility aids on top of your luggage allowance but this varies depending on the carrier so it is always best to check with your airline.