@liz440 Within the last month, I've started Spiriva, an anticholinergic, for asthma (it's also used for COPD in a higher dose). While it doesn't seem to interfere with clearance I have noticed less mucus. As explained to me by doctor, anticholinergics work by relaxing the smooth muscles in the airways, helping them to widen and improve airflow. Benadryl is an antihistamine and anticholinergic. Often a med trial can be helpful in figuring out if it's helpful or not.