Just returned from a trip to Italy that included a cruise around Italy and to Croatia. My Pulmonologist put me on a course of prednisone and gave me suckers made in their pharmacy to deal with coughing, especially on the airplane. They helped tremendously? There is a great deal of walking and stairs to see the sites and I should have brought my oxygen concentrator. I did bring my CPAP and portable nebulizer. (Viking supplied our cabin with distilled water daily.) Great trip. Use what you've learned.