 [ Symptoms ] i have been taking generic toprol xl 50 mg and i am excreting the medication still intact is something wrong [ Disease ] children is pepto bismol contains calcium carbonate an antacid it is safe to take with cephalexin with calcium carbonate there are no drug interactions to be concerned about if you are trying to treat diarrhea caused by an antibiotic i suggest you talk to your pharmacist or pediatrician children is pepto bismol does not treat diarrhea