cimetidine

drug

Also known as: Tagamet

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Last updated

June 24, 2026

Quick Summary

Cimetidine is a medication that functions as an H₂ receptor antagonist. This means it blocks histamine from stimulating the secretion of gastric acid in the stomach.1

Developed by Sir James Black, who received a Nobel Prize for his work on drugs like cimetidine, it is used to treat conditions such as gastroesophageal reflux and peptic ulcers, often in combination with antibiotics. Cimetidine is a histamine analog with the chemical formula C₁₀H₁₆N₆S.123

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H2 receptor antagonist
Sir James Black
cimetidine

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- antihistamine
  H2 receptor antagonists
  …first of these agents was cimetidine (Tagamet). These drugs were shown to be extremely effective in antagonizing the action of histamine in stimulating acid secretion and in blocking other stimulants of acid secretion, including the hormone gastrin and food. The H₂-receptor antagonist drugs, such as cimetidine and ranitidine, rapidly established…
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  …first of these agents was cimetidine (Tagamet). These drugs were shown to be extremely effective in antagonizing the action of histamine in stimulating acid secretion and in blocking other stimulants of acid secretion, including the hormone gastrin and food. The H₂-receptor antagonist drugs, such as cimetidine and ranitidine, rapidly established…
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- Sir James Black
  …two important drugs, propranolol and cimetidine.
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  …two important drugs, propranolol and cimetidine.
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- therapeutics
  Indications for use
  Cimetidine, a drug used to treat peptic ulcers, causes few side effects by itself, but it does inhibit drug-metabolizing microsomal enzymes in the liver, increasing concentrations of many drugs that depend on these enzymes to be metabolized. This inhibition can be serious if the other…
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  Cimetidine, a drug used to treat peptic ulcers, causes few side effects by itself, but it does inhibit drug-metabolizing microsomal enzymes in the liver, increasing concentrations of many drugs that depend on these enzymes to be metabolized. This inhibition can be serious if the other…
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H2 receptor antagonist
These drugs, which include cimetidine (Tagamet) and ranitidine (Zantac), are used for short-term treatment of gastroesophageal reflux and, in combination with antibiotics, for peptic ulcer.
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These drugs, which include cimetidine (Tagamet) and ranitidine (Zantac), are used for short-term treatment of gastroesophageal reflux and, in combination with antibiotics, for peptic ulcer.
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digestive system disease
Ulcerative diseases
Histamine-receptor antagonists, such as cimetidine, ranitidine, and famotidine, block the action of histamine on the acid-secreting parietal cells of the stomach. Proton pump inhibitors, such as omeprazole, lansoprazole, and rabeprozale, inhibit the ATPase enzyme inside the parietal cell and prevent acid secretion. Most peptic ulcers not caused by H.…
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Histamine-receptor antagonists, such as cimetidine, ranitidine, and famotidine, block the action of histamine on the acid-secreting parietal cells of the stomach. Proton pump inhibitors, such as omeprazole, lansoprazole, and rabeprozale, inhibit the ATPase enzyme inside the parietal cell and prevent acid secretion. Most peptic ulcers not caused by H.…
Read More