Cimetidine was the culmination of a project at Smith, Kline and French (SK&F; now GlaxoSmithKline) by James W. Black, C. Robin Ganellin, and others to develop a histamine receptor antagonist to suppress stomach acid secretion.
Galactorrhea is also a side effect associated with the use of the second-generation H2 receptor antagonist Cimetidine (trade name: Tagamet).