Efletirizine is histamine H1 receptor antagonist. Restricted to topical use. It was under investigation in Phase III (in Europe) clinical studies for the treatment of allergic rhinitis and chronic idiopathic urticarial. Research was discontinued in 2005 due to limited clinical efficacy and safety data. Efletirizine also reduced ocular itching.

Nemazoline (A-57219) is a nasal decongestant. It has alpha 1-agonist/alpha 2-antagonist activity and was more effective and long-acting than oxymetazoline on canine nasal mucosa, in-vitro and in-vivo. Upon intranasal administration to dogs, the compound was devoid of systemic effects up to a concentration 1000 times that needed for local decongestant effect (1.65 micrograms, atomized from a 1 microgram mL-1 solution) suggesting limited mucosal absorption. After nasal administration to rats for 15 days at a concentration 1000 times greater than that required for nasal decongestion, no mucosal tissue toxicity or systemic effects were seen.

Phenamazoline is an antazoline derivative. It is a sympathomimetic agent. It was developed as vasoconstrictor but its carbon analog is a vasodilator.

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

Etintidine is a potent competitive antagonist of histamine H2-receptors. It has a low level of antiandrogenic activity. Etintidine was being investigated in the treatment of peptic ulcer, however, its development has been discontinued.

Cycliramine is a substituted piperidine derivative discovered by Schering Corp. The drug is claimed to have antihistamine, antispasmodic, antiacetylcholine and analgesic activity.

There is no information about biological and medical application of dorastine . It’s known, that compound possesses antihistamine properties and can be obtained from 4-chloroaniline.

Methaphenilene, an antihistaminic agent, was studied as a peroxisome proliferator. Information about the current use of this compound is not available.

Tixocortol is a synthetic steroid with topical anti-inflammatory properties. In form of Tixocortol pivalate, also known as Pivalone, it is used to treat the inflammatory and allergic manifestations of the rhino-pharynx: allergic rhinitis, acute and chronic congestive rhinitis, vasomotor rhinitis. In addition, it has been shown to be a useful agent for assessing corticosteroid contact dermatitis, particularly for hydrocortisone-type derivatives. Labeled adverse effects are: itchy nose, dryness of the nasal mucosa, edema of the face mucosa, cataract, glaucoma, Cushing syndrome, skin thinning.

Emedastine is an antihistaminic agent, which was approved by FDA for the treatment of allergic conjunctivitis (Emadine brand name). The drug acts selectively on H1 receptors with lower affinity to H2 and H3 subtypes. Emedastine has a relatively unfavorable CNS effect profile. A small percentage of patients reported somnolence as an adverse effect after administration.