I'm 67 years old and I have congestive heart failure. I was recently in the vicinity of someone who was maced, and as hard as I tried, I couldn't escape the airborn spray. Since then, I haven't been able to stop coughing. My medication usually controls the fluid from building up in my lungs, but it doesn't seem to be working as well as usual now. Is it safe for me to use any over the counter cough expectorants? I'm currently taking CARVEDILOL, LISINOPRIL, HYDROCHLOROTHIAZIDE, AND ASPIRIN. Do cough medicines ever conflict with these medications?