Pepcid causes acid rebound when taken together with other medications like aspirin, ibuprofen, naproxen, etc. If you take these drugs together, then you may experience heartburn, indigestion, stomach pain, nausea, vomiting, diarrhea, constipation, headache, dizziness, drowsiness, dry mouth, blurred vision, ringing in the ears, tinnitus, and skin rash. These symptoms usually go away after stopping taking the medication.