Can Splenda cause a reaction with Asthma. I have noticed a few times a day I have mild chest pain (more tightness) and breathing like an asthma attack but milder a few times a day. At first I was worried about a heart attack (as I worry about everything) I started using Splenda in place of sugar in coffee a few days + from noticing this. Just curious if there have been cases of Splenda aggravating asthma.