EFFECTS OF CHANGING THE TYPE OF H-2-BLOCKER IN THE TREATMENT OF H-2-BLOCKER-RESISTANT ULCERS - COMPARISON OF ROXATIDINE ACETATE HYDROCHLORIDE AND OTHER H-2-BLOCKERS

The efficacy of switching from one type of H-2-receptor antagonist (H- 2-blocker) to another, in the treatment of H-2-blocker-resistant ulcer s was investigated using H-2-blockers with five-membered rings (five-m embered-ring agents) - such as cimetidine, ranitidine and famotidine - and an H-2-blocker with a six-membered ring, roxatidine. By switching from a five-membered-ring agent to roxatidine in the treatment of fiv e-membered-ring resistant ulcers (study I), gastric ulcers were healed in nine of 19 patients (47%) and duodenal ulcers were healed in eight of nine patients (89%). By switching from roxatidine to one of the fi ve-membered-ring agents in the treatment of roxatidine-resistant ulcer s (study II), gastric ulcer was healed in six of 15 patients (40%), an d duodenal ulcer was healed in 4 of 10 patients (40%). Particularly in the case of duodenal ulcers, the switch to treatment with roxatidine, which has a different chemical structure from the five-membered-ring agents, may be useful in the treatment of five-membered-ring-resistant ulcers.