Has more side effects than Allegra since it has pseudoephedrine in it. The antihistamine (fexofenadine) can cause dizziness, drowsiness, dry eyes/mouth, and constipation. The decongestant (pseudoephedrine) can make your blood pressure higher and can make it harder to sleep.
Food preservatives (or additives) contained in certain foods can trigger headaches. Nitrates and nitrites are additives in: 1  Hot dogs. 2  Ham. 3  Sausage. 4  Bacon. 5  Lunch meats and deli-style meats.6  Pepperoni.7  Other cured or processed meats. 8  Some heart medicines.ood preservatives (or additives) contained in certain foods can trigger headaches. Nitrates and nitrites are additives in: 1  Hot dogs. 2  Ham. 3  Sausage. 4  Bacon. 5  Lunch meats and deli-style meats. 6  Pepperoni. 7  Other cured or processed meats.
Sodium Nitrite and Sodium Nitrate in Food. Used as a preservative in meats, these chemicals may pose a cancer risk, although the evidence remains controversial. One recent study raised fears that nitrites and nitrates could interact with medications to damage DNA and increase the risk of cancer.