This article explains about the use of non prescription drugs for the treatment of common cold symptoms which a person with diabetes should avoid and why. (It includes Sudafed).
Oral decongestants as a category HAVE THE MOST POTENTIAL FOR affecting BS control........... https://nfb.org/images/nfb/publications/vod/vodspr0403.htm
I had a look myself as well and it also said that for T2s, there's an issue with BP increase as well. I've only been taking one tablet a day, but I'm feeling a bit beter now so I'll knock it on the head in favour of the usual pain relief.