Cimetidine, ranitidine, and famotidine are related medicines. They are in a class of drugs called H2 blockers. They have similar effects and uses in veterinary medicine.
H2 blockers cause decreased production of stomach acid. In pets, these medicines are prescribed mainly to treat or prevent gastrointestinal upset (vomiting, diarrhea, or lack of appetite). They also may be used to prevent or treat ulcers or irritation of the esophagus, stomach, or intestines.