The changing role of H2-receptor antagonists in acid-related diseases.

BACKGROUND

H2-receptor antagonists have been the mainstay of treatment for acid-peptic disease for many years. These compounds have proved to be more effective than antacids and without relevant side effects. However, their primacy has recently been challenged. First, the discovery of Helicobacter pylori and its effects on peptic ulcer disease has indicated the need for antimicrobial therapy. Second, the development of proton-pump inhibitors with potent and long-lasting antisecretory effects has largely changed the approach to acid inhibition therapy. DIFFERENCES BETWEEN H2-RECEPTOR ANTAGONISTS AND PROTON-PUMP INHIBITORS: There are important differences in the mechanism of action whereby H2-receptor antagonists and proton-pump inhibitors reduce gastric acid secretion. These differences lead to differences in the degree and duration of acid inhibition: repeated doses of proton-pump inhibitors are needed in order to reach the maximum antisecretory effect, whereas the acid-inhibitory effect of H2-receptor antagonists is achieved within hours, although it tends to fade during prolonged treatment.

CONCLUSIONS

For erosive and ulcerative reflux esophagitis, H2-receptor antagonists have been largely replaced by proton-pump inhibitors, while for peptic ulcer disease, therapy for H.pylori eradication is now recommended. In the future, H2-receptor antagonists may be used mainly for mild to moderate gastroesophageal reflux disease and these drugs may be available as over-the-counter medication in several countries.