H2 Blockers

We talked about H2 receptors previously. They are found in the stomach and when stimulated, acid is released, which is important for digestion. We have a problem though if an excess amount is being produced, especially if an ulcer is present. So H2 blockers stop this secretion but it still takes 6-8 weeks for an ulcer to heal regardless. It’s a good drug class to help prevent ulcers from recurring. A patient with idiopathic ulcers may be on this drug. Also patients who have to be on drugs long term and may develop drug induced ulcers may also be on an H2 blocker. Our biggest problem is nocturnal acid with antacids but this is long acting enough so it works long enough.

Examples (Anything that ends in -tadine is a H2 blocker so it’s easy to recognize.)

• Cimetidine (Tagamet) – p.o., inj
• Ranitidine (Zantac) – p.o., inj.
• Famotidine (Pepcid) – p.o.

• Blocks H-2 receptor in stomach
• Blocks secretion of acid
• Promotes healing of ulcers (6 to 8 weeks)
• Utilized to prevent recurrence of ulcers (life long therapy)
• Prevents nocturnal acid