Key takeaways
Cimetidine (Tagamet HB) and esomeprazole (Nexium) are both used to treat conditions caused by too much stomach acid, but they belong to different drug classes. Cimetidine is a histamine H2 receptor antagonist (H2RA) that works by blocking histamine in the stomach, which reduces acid production. Esomeprazole, on the other hand, is a proton pump inhibitor (PPI) that blocks the final step of acid production in the stomach. Cimetidine can be taken up to four times a day and is available both over-the-counter (OTC) and by prescription. Esomeprazole is typically taken once a day and is also available OTC and by prescription. Cimetidine may start working faster but might not be as effective with long-term use, whereas esomeprazole takes a few days to fully kick in but provides longer-lasting relief. Cimetidine has more drug interactions compared to esomeprazole, which can affect how other medications are absorbed or broken down in your body. Esomeprazole, however, has significant interactions with clopidogrel (Plavix) and can affect bone health with long-term use. Both medications have generic forms available.
