Which medication is known as a H2 histamine receptor antagonist?

Zantac is recognized as a H2 histamine receptor antagonist, making it the correct choice. This class of medication works by blocking histamine at the H2 receptors in the stomach lining, effectively reducing the production of stomach acid. This mechanism is beneficial for treating conditions like gastroesophageal reflux disease (GERD) and peptic ulcers, as it helps alleviate symptoms by decreasing acidity levels in the stomach.

In contrast, the other medications listed serve different purposes: Zoloft is an antidepressant that belongs to the selective serotonin reuptake inhibitor (SSRI) class, primarily used to treat depression and anxiety disorders. Zocor is a statin used to lower cholesterol levels, contributing to cardiovascular health. Zyprexa is an antipsychotic medication used to treat conditions such as schizophrenia and bipolar disorder. Each of these medications works through distinct pathways and is indicated for different medical concerns, which is crucial for understanding their respective roles in patient care.