Bamirastine (previously known as TAK 427), an antiallergic compound that inhibits ligand binding to recombinant human histamine H1 receptor. The drug was involved in phase II clinical trials for the treatment of allergic rhinitis and for patients with atopic dermatitis. However, these studies were discontinued.

Pipoxizine is the antihistamine agent and antiserotonin agent. It was used as antiarrhythmic and bronchodilator.

Embramine or mebrophenhydramine is an antiallergic agent. Embramine is a histamine H₁-receptor antagonist exerting anticholinergic activity. It may inhibit stimulated platelet functions by inhibiting phospholipase A2. It is prescribed for severe allergic conditions.

FENETHAZINE was a first-generation phenothiazine-derived antihistamine drug. Promethazine was derived from FENETHAZINE.

Libecillide is a specific monovalent penicilloyl hapten inhibitor of allergic reactions to penicillin. A depression of skin hypersensitivity to PPL and/or penicillin and penicillin derivatives sometimes persisting for weeks and months was obvious in numerous allergic patients submitted to combined libecillide-penicillin treatment. A depressing effect on antipenicillin antibody titers detected by passive hemaglutination was also manifest in some patients. The overall tolerance of libecillide in allergic patients has been very good. Nevertheless, the major obstacle to a wider general use of libecillide at the present time appears to be the occurrence of positive skin reactions to that compound in approximately 5 percent of patients allergic to penicillin.

Quinotolast (also known as FK021) is an orally active mast cell stabilizer which has a cytoprotective effect on the gastric mucosa. Quinotolast was patented in 1985 by Japanese pharmaceutical company Fujisawa Pharmaceutical Co., Ltd. as an antiallergic and antiulcer agent. In preclinical models, Quinotolast potently inhibited such type I allergic reactions as passive cutaneous anaphylaxis (PCA) and anaphylactic bronchoconstriction in rats by both intravenous and oral dosing. Quinotolast inhibited histamine release from rat peritoneal cells, but it had no antagonistic effect on histamine-, serotonin-, platelet activating factor- or bradykinin-induced cutaneous reactions in rats. Moreover, it was clearly demonstrated that quinotolast and DSCG had a cross tachyphylaxis to inhibit PCA in rats, suggesting that these drugs, at least in part, share the same mechanism of action. Quinotolast caused a significant increase in the mucociliary transport rate in quails. Quinotolast significantly depressed the cough reflex induced by citric acid in normal and bronchitic guinea pigs.

Furethidine, a pethidine analog was studied as an analgesic agent. This compound is not currently used in medicine and is listed in schedules of the single convention on narcotic drugs of 1961 as amended by the 1972 protocol.

Clorisamine is an antihistamine drug developed by Schering in the 1970s. The drug was evaluated in phase 1 clinical trial on healthy volunteers. The results show that in a therapeutic dose of 2 mg the drug did not have any effects which might lead to an impairment of driving ability.

Pyroxamine (also known as AHR 224) is benzhydryl ethers of 3-pyrrolidinol patented by A. H. Robins Co., Inc. as antihistamine with bronchodilation activity. In preclinical studies, Pyroxamine shows moderate inhibition of histamine-induced ulceration in guinea pigs