Key takeaways
Famotidine (Pepcid AC) and esomeprazole (Nexium) are both used to treat conditions caused by too much stomach acid, but they belong to different medication classes. Famotidine is a histamine-2 (H2) antagonist, while esomeprazole is a proton pump inhibitor (PPI). Famotidine works by lowering the amount of stomach acid released by certain cells in your stomach lining, and it starts working within an hour. In contrast, esomeprazole blocks the final step of stomach acid production and can take a few days to show full effects. Famotidine is available both over-the-counter and by prescription, and it can be taken as a tablet or liquid. Esomeprazole is also available over-the-counter and by prescription and comes in capsules, tablets, and a liquid suspension. Famotidine is typically taken twice a day, while esomeprazole is usually taken once a day. Famotidine is generally well-tolerated but can cause headaches and dizziness, whereas esomeprazole can lead to headaches, belly pain, and potential long-term issues like weakened bones. Both medications can interact with other drugs, so it's important to discuss all your medications with a healthcare professional.
