Prozac (fluoxetine) and Pepcid. Fluoxetine is a medication for Depression and Anxiety. Its side effects can be- nausea, dyspepsia, abdominal pain flatulence and diarrhea. If you do not have these side effects, you can take Pepcid (famotidine). Pepcid (famotidine) is for hyperacidity which can be due to stress. Let wise man within you guide you to understand your stress, to learn coping skills for anxiety, depression; and relaxation by a Psychiatrist.