I'm asking for a friend, here's her message: I'm trying to figure out brand names and active ingredients of H1 receptor blockers, H2 receptor blockers and mast cell stabilizers. Can you help? Here's my tentative list - very grateful for corrections and additions of brand names: H1 blockers: Diphenhydramine Loratadine Fexofenadine Cetirizine Levocetirizine H2 blockers: Cimetidine Ranitidine Famotidine Nizatadine Mast cell stabilizers: Ketotifen Doxepin Hydroxyzine Pentosan Where do desloratadine and alimemazine fit in? Is the list otherwise correct? Can you help me with brand names? Many thanks!