A conformational approach to histamine H2-receptor antagonists.

Four selective H2-antagonists were studied: burimamide, thiaburimamide, metiamide and cimetidine and their conformations were investigated using the PCILO method. The results show similar preferred conformations but also show that the most active drugs can more easily assume conformations different from the preferred ones. The selective H2-agonist dimaprit was also examined in order to find conformational features determining activity at the H2-histamine receptor.