Does Robitussin Cause Hunger?

Hi, I currently have a flu...and earlier I had a filled with quite a bit of acidic foods containing lemon. The medicine I'm taking is Robitissum. Since I began taking the medicines, I have this feeling of hunger after even though I ate right before. But just a few minutes ago, it became really bad and I almost vomited. This salty warm taste came to my mouth. I'm wondering what's happening.