Ketotifen is unique in its ability to upregulate the beta adrenergic system and reduce TNF, possibly pizotifen, which is used in the US, can do this but I have not found any information on this.
There is no evidence that H2 blockers, such as Tagamet or Pepcid, have this ability. Likewise, the common H1 blockers, such as diphenhydramine or chlor- and brompheniramine, do not share in this ability.