Ebastine is an antihistamine which blocks H1-receptors through its carboxylic acid metabolite. Ebastine is indicated for the treatment of allergic rhinitis and chronic idiopathic urticaria.

Laropiprant is a drug, which was used in combination with nicotinic acid (also known as niacin) and was known under tradename: tredaptive. Tredaptive was indicated as adjunctive therapy to diet for use in patients with primary hypercholesterolaemia (heterozygous familial and non-familial) or mixed dyslipidaemia. The marketing authorisation for Tredaptive has been withdrawn at the request of the marketing-authorisation holder due to increases in side effects with no cardiovascular benefit. Laropiprant is a selective antagonist of the prostaglandin D(2) (PGD(2)) receptor subtype 1 (DP1). It also has the affinity to interact with thromboxane A2 receptor (TP), although it is approximately 190-fold less potent when compared to DP1. Activation of TP has been shown to induce platelet aggregation in vitro, whereas activation of human platelet DP1 inhibits platelet aggregation. These in vitro data indicate that laropiprant may alter platelet function either by enhancement of platelet reactivity through DP1 antagonism or by inhibition of platelet aggregation through TP antagonism. Also were clinical trials phase II for the laropiprant alone, there were shown, that drug did not demonstrate efficacy in asthmatic patients or patients with allergic rhinitis.

Rupatadine is characterised as a non-sedating H1 anti-histamine and platelet-activating factor (PAF) receptor antagonist. Rupatadine is indicated for the treatment of allergic rhinitis and urticaria. Rupatadine is a safe and well tolerated drug in patients over 2 years old, with no central nervous system or cardiovascular effects and it can be taken with or without foods.

Levopropylhexedrine acts similar to amphetamine, at therapeutic doses has anorexigenic effect.

Bilastine is a new second generation H1-antihistamine recently approved for the symptomatic treatment of allergic rhinitis (AR) and chronic urticaria (CU). Bilastine is an H1 receptor inverse agonist. Bilastine also exerts anti-inflammatory activity by inhibiting the release of histamine, IL-4 and tumor necrosis factor (TNF)-α from human mast cells and granulocytes. Common side effects are headache and drowsiness.

Pranlukast is an antagonist of cysteinyl leukotriene receptor-1 antagonist. It is marketed in Japan by Ono Pharmaceuticals under trademark ONON for the treatment of bronchial asthma and allergic rhinitis as capsules and dry syrup for pediatric use.

Tranilast is an antiallergic drug developed by Kissei Pharmaceuticals. It was approved in 1982 for use in Japan and South Korea for bronchial asthma. Indications for keloid and hypertrophic scar were added in 1993. It has been used for the treatment of allergic disorders such as asthma, allergic rhinitis and atopic dermatitis. Tranilast is used for the treatment of bronchial asthma, keloid and hypertrophic scar, and allergic disorders such as asthma, allergic rhinitis and atopic dermatitis.

Mequitazine (PRIMALAN®) is a phenothiazine derivative and a histamine H1-receptor antagonist. It competes with histamine for the normal H1-receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies.

Leukotriene D4 (LTD4, 5(S)-hydroxy-6(R)-S-cysteinylglycyl-7,9,11,14-(E, E, Z, Z)-eicosatetraenoic acid) is a pro-inflammatory mediator produced by eosinophils and mast cells, that is known to mediate its effects through specific cell-surface receptors belonging to the G-protein-coupled receptor family, namely the high-affinity CysLT (cysteinyl leukotriene) receptor. LTD4 is associated with the pathogenesis of several inflammatory disorders, such as asthma and inflammatory bowel disease. LTD4 is triggering many processes central to asthma – mucus secretion, bronchoconstriction and increased vascular permeability. Potent LTD4 antagonists protect (by about 50%) against exercise- and allergen-induced bronchoconstriction, suggesting that leukotrienes contribute to bronchoconstrictor responses. Leukotriene D4 has been used in trials studying the diagnostic of Asthma and Allergic Rhinitis.

Bepotastine is a non-sedating, selective antagonist of the histamine 1 (H1) receptor. It belongs to the second-generation piperidine chemical class. It is a mast cell stabilizer and suppresses the migration of eosinophils into inflamed tissues. Bepotastine was approved in Japan for use in the treatment of allergic rhinitis and uriticaria/puritus in July 2000 and January 2002, respectively, and is marketed by Tanabe Seiyaku Co., Ltd. under the brand name Talion. It is available in oral and opthalmic dosage forms in Japan. The opthalmic solution is FDA approved since Sept 8, 2009 and is under the brand name Bepreve.