I am also in a study with the eflow (the aztreonam study), and I was also advised NOT to do other meds in it, but that was over a year ago. I would say at least for the study part of it, NOT to do other meds with the eflow. What happens is that (at least with the study I am in) they collect the plastic parts of the neb every other month, I guess just to test them out and make sure they are still working correctly. They give me new plastic pieces every time I am on the drug (which is every other month). If you had two sets of plastic pieces or could get a second set, MAYBE, but for the sake of the study I wouldnt use the eflow for other meds. I have also been advised that they will be collecting my eflow machine at the end of the study to test for durability and also make sure it still works correctly. The more you use it, the more wear and tear it will have, and thus may make the eflow less durable at the end of the study you are in.