Hi Lynne, Thank you for your question. There is no documented drug interaction between enalapril and famotidine, so they should be okay to take together. You mentioned that the famotidine is a new medication and was switched from omeprazole. It's important for you to know that these medications work differently. Though they both work to reduce the amount of acid in the stomach, they work in two different ways. Nexium is similar to omeprazole - they are both known as PPIs. Famotidine, however, is known as an H2 antagonist. If your symptoms are not resolved with famotidine treatment, you should discuss with your doctor whether the dose can be increased or another medication can be tried. I hope this helps! Best of luck, Casey