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.

Vipadenant (V2006) is a small molecule, adenosine A2A receptor antagonist that was being investigated in Parkinson's disease. Due to safety concerns development ceased in 2010 and the rights were regained from Biogen Idec in 2011 with no further investment made. In October 2014, RedoxTherapies licensed Vipadenant as it has the potential to disrupt an immunosuppressive mechanism of tumour protection, generating improved efficacy for immunotherapies of certain cancers when used in combination with other drugs.

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.

Azimexon, a synthetic derivative of the 2-cyanaziridines, possesses the immunorestorative properties that were shown for patients with acquired immunodeficiency syndrome. Besides, azimexon had a role in managing cancer-associated dysregulation of the immune response. It was studied in clinical trials phase I to determine the drug's tolerable dose, toxicity, and effects on immune and nonimmune host defense parameters.

EC-18 (now known as mosedipimod), a synthetic copy of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) that was developed by Enzychem Lifescience for oral administration for the treatment of immune and inflammatory related diseases, including psoriasis, rheumatoid arthritis, asthma, atopic dermatitis, and sepsis. The US Food and Drug Administration (FDA) has granted Orphan Drug Designation to EC-18 for the treatment of Acute Radiation Syndrome (ARS) and for the for the neutropenia treatment. Besides, the EC-18 is participating in phase II clinical trials to investigate the efficacy and safety of the agent for chemoradiation-induced oral mucositis and chemotherapy-induced neutropenia. This drug has a multimodal mechanism of action. It stimulates calcium influx into T lymphocytes and increases the production of various cytokines. In addition, EC-18 enhances the cytolytic activity of natural killer (NK) cells and suppresses the expression of the transmembrane protein tumor cell toll-like receptor 4 (TLR-4) on cancer cells, thus suppresses tumor cell proliferation.