I wouldn't eat a whole bag of them at once, but I don't think the amount of anything in a couple of cough drops could hurt anything. I have never heard that they are unsafe but of course like everything they say "consult your doctor if you are pregnant or nursing" Personally I just go ahead and use them.
If you feel nervous about it get Ludens or something that is essentially just a sucking candy. Honey is one of the best things for a sore throat from a cold, drink some decaf tea with honey or get some of those honey sucking candies if you want to avoid the cough drops. Hope you feel better soon!