- histamine blocker - a medicine used to treat the gastric effects of histamine in cases of peptic ulcers and gastritis and gastroesophageal reflux; works by blocking the effects of histamine on the receptor site known as H2
--1 is a kind of medicine, medication, medicament, medicinal drug
--1 has particulars:cimetidine, Tagamet; famotidine, Pepcid; ranitidine, Zantac