I don't take cough syrup, but my COPD Meds raise mine. Have you googled it up to see?

it can from what I have heard. I usually will get bronchitis once a year and I use the over the counter cough syrups as that, and have not noticed too much of a difference, of course we don't know if it is being sick or the cough syrup raising numbers. There is a diabetic type cough syrup also

I think it is hard to tell if it is the cough syrup or the cold/cough causing the spikes. It is a catch 22 when you need cough meds. because you need it and then again you don't want spikes. I have tried the sugar free cough syrup and you will need to swallow quickly as the taste is not pleasant. :p

LOL that it is

Might that be sugar-free Tussin?

https://www.4mdmedical.com/index.php/catalog/product/view/id/6120/s/goodsense-tussin-dm-cough-suppressant-expectorant-sugar-free-4-oz/?utm_medium=cse&utm_source=google&gclid=CKigrpSCjbsCFcFj7AodnB0Auw