# Histamine Receptor Antagonists
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**Histamine-2 receptor antagonists** (sometimes called **H2 blockers**) are a class of [[medicine]] that work as [[peptic ulcer disease|antiulcer]] agents.
They decrease [[stomach acid|gastric acid]] production, which allows for the healing an prevention of [[peptic ulcer disease|peptic ulcers]] as well as improve the effects of [[GERD]].
## Contraindications
Use cautiously for renal impairment.
## Adverse Reactions
The most common side effect is confusion.
## Examples
- **Famotidine** (brand name: **Pepcid**)
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