Side effects of famotidine include headache, dizziness, diarrhea and constipation. Other rare but dangerous side effects are easy bleeding, bruising, heart beat irregularities, signs of infection, mood changes, mental status changes, and seizures, according to WebMD.
Famotidine is also known by its brand name, Pepcid AC, and belongs to the same class of drugs as cimetidine and ranitidine. It blocks the action of histamine on acid producing cells in the stomach, which results in the decrease in acid production. It is prescribed for heartburn, healing esophageal ulcers, and Zollinger-Ellison syndrome, states MedicineNet.com.
Famotidine is associated with several drug interactions, and may cause a decrease in the absorption of other drugs because of the decrease in acid production. Some of these drugs include atazanavir, dasatinib, delavirdine, itraconazole, and ketoconazole, according to MedicineNet.com.
The FDA classifies famotidine as a category B drug, which means it has not been found to cause fetal damage in animal studies. Pregnant women should take the drug only if the benefits of taking it outweigh the risks. Famotidine shows up in breast milk in levels lower than the doses prescribed to newborns. It is therefore not considered dangerous for breastfeeding mothers to take famotidine, according to Drugs.com.