how much famotidine can you take in a day
1 The total dose is usually not more than 40 mg per day. 2  To treat gastroesophageal reflux disease (GERD): 3  Adultsâ20 milligrams (mg) two times per day. 4  Teenagers and children above 1 year of ageâDose is based on body weight and must be determined by your doctor.