Pibaxizine is diphenylmethyl piperazine derivatives. It is a histamine H1 receptor antagonist. Animal experiments have shown that it has spasmolytic properties for smooth muscle, particularly in the bronchi, as well as anticholinergic and anti-serotonin activities. It can be concluded that Pibaxizine has a strong protective effect against bronchospasm caused by inhalation of a histamine aerosol. Protection against methacholine-induced bronchospasm was less marked. Pibaxizine had been in phase II clinical trial for the treatment of chronic obstructive pulmonary disease. However, this development was discontinued.

Icotidine (also known as SKF 93319) was developed as histamine H1- and H2-receptor antagonist and possessed antinociception properties. Due to its antagonist activity, was suggested that compound could have therapeutic in some inflammatory skin diseases such as the urticarias and mastocytosis.

Mifentidine, a histamine H2 receptor antagonist, was studied to treat the duodenal ulcer. This drug was in phase II clinical trials when apparently further researches had been discontinued.

Tecastemizole (aka Norastemizole) is an H1 receptor antagonist that showed great promise as potential next-generation antihistamine allergy medication. Sepracor developed Norastemizole through phase III clinical trials; however, the FDA rejected the application for approval on the grounds of an unacceptable profile of adverse side-effects including phospholipidosis and cardiomyopathies in animals exposed to the drug.

Tiacrilast (also known as Ro 22-3747) is a quinazolinyl-propenoic acid derivative patented by Hoffmann-La Roche, Inc. as an antihypertensive useful for anaphylaxis management. Tiacrilast acts as a potent mast cell degranulation inhibitor in vitro and inhibits of antigen-induced histamine release from passively sensitized rat peritoneal cells in vitro. In preclinical models, Tiacrilast shows marked activity in rat passive cutaneous anaphylaxis assay, rat anaphylactic bronchospasm assay. In vitro studies have confirmed that the mechanism of action of Tiacrilast in the in vivo models is through allergic mediator release inhibition. Clinical evaluations of Tiacrilast in patients with ragweed sensitive allergic asthma, Tiacrilast demonstrates significant inhibitory activity relative to placebo in reducing acute airway responses to inhaled pollen extracts

Zinc dibutyldithiocarbamate (Zn DBDTC) is a vulcanization accelerator for natural rubber and latex and a stabilizer for rubber-based adhesive systems, isobutylene-isoprene copolymers and polypropylene. It is used in a number of rubber and rubber-based materials for food packaging and food handling, e.g. conveyor belts. Zinc dibutyldithiocarbamate (Zn DBDTC) is contact allergens that cross-react in some individuals. Zinc dibutyldithiocarbamate, like many low-molecular-weight contact allergens, can only trigger an immune response when bound to a protein in the form of an immunogenic protein–hapten complex. Haptenation of epidermally relevant skin proteins by Zinc dibutyldithiocarbamate has not been reported despite the numerous studies on the disposition and systemic toxicity of Zinc dibutyldithiocarbamate. The chelating properties of the dithiocarbamate ligand have been proposed to be responsible for the modification of some metalloproteins and metalloenzymes

Bisphenol A diglycidyl ether (BADGE) is a ligand for peroxisome proliferator-activated receptor gamma (PPARgamma); in addition, this compound can antagonize the ability of agonist ligands such as rosiglitazone to activate the transcriptional and adipogenic action of this receptor. The elevation of BADGE concentration in epoxy resins-coated aluminium tubes poses a risk of developing contact dermatitis to patients sensitized to epoxy resins.