I have hives caused by antibiotics. benadryll not tolerated during the day. i was told by walk in to take tagament and claritin (loratadine). why the tagament?

H2 blockade: Some believe that tagamet, (cimetidine) a "blocker" of another histamine receptor (histamine 2) may enhance the effect of histamine 1 "blocker" but there is no strong evidence to support it. On the other hand, i prefer antihistamine other than Loratadine for hives. Consider taking the antihistamine up to 4 x daily if needed.

Histamine blocker: Tagamet (cimetidine) is an h2-blocker. Although the histamine pathway this is mainly involved with is for acid blockade, to a certain extent it can also help with allergic reactions.