He definitely needs something stronger than Clindamycin. Like Amy mentioned being 25 points down alone (no matter how high his pft's are) is a big red flag that something is going on. Bleeding is usually from infection but not always, but with his other symptoms pain and crackles it sounds like he has some infection going on and needs iv's. He doesnt have to go in the hospital for iv's unless thats the policy of your particular cf clinic. I do all of mine at home and it allows me to continue going to work , eat normal food, do normal things , remain active and not miss out on anything. Please call the Dr. tomorrow and ask to be seen asap. I wouldnt wait for 2 weeks if it were me, it sounds like he needs attention now.