Pimethixene is an antihistamine exerting sedative and antitussive properties. Pimethixene displayed high affinity to serotonin 5-HT2A and 2B, histamine H1 and muscarinic acetylcholine M2 receptors. Oral pimethixene used to calm dry cough and irritation coughs in children.

Bufenadrine is a derivative of diphenhydramine. The compound was originally developed as an anti-motion sickness drug. Prolonged toxicity studies in rats, however, showed liver toxicity, and no further clinical evaluation was undertaken. Investigation of the metabolism showed that (-)-bufenadrine was enantiomer, exclusively responsible for toxic activities of the racemic compound.

Bamipine (trade name Soventol) is a sedating antihistamine with pronounced sedative effects. Bamipine is a pharmaceutical drug acting as an H1 antihistamine with anticholinergic properties. It is used as an antipruritic ointment. Bamipine hydrochloride has been given by mouth. Bamipine, bamipine lactate, and bamipine salicylate have all been applied topically.

Batebulast (NCO-650) is an anti-allergic drug. It significantly inhibited both the initial and secondary increases in cAMP stimulated by antigen, anti-IgE and concanavalin A (Con A) in rat peritoneal mast cells. It strongly inhibited the incorporation of the 3H-methyl moiety into phospholipid by antigen, anti-IgE and Con A during histamine release. Batebulast significantly inhibited the compound 48/80-induced bronchoconstriction in dogs. Batebulast had no effect on the bronchoconstriction induced by inhalation of acetylcholine, suggesting that NCO-650 appears to have no anti-cholinergic effect and thus no effect on the vagal reflex that occurred during the asthmatic responses. NCO-650 may be useful for the treatment of bronchial asthma as an orally active drug. Batebulast has been in phase II clinical trials for the treatment of asthma in Japan. However, this research has been discontinued.

Pibutidine hydrochloride (IT-066), a novel histamine H2 receptor antagonist has powerful and long lasting antisecretory and antiulcer effects and is a useful antisecretory drug for treatment of peptic ulcer diseases.

Arpromidine is a potent histamine H2-receptor agonist and weak NPY Y1 antagonist. In the isolated aperfused heart, arpromidine was more potent in increasing cardiac contractile force and coronary flow but less effective on heart rate and less arrhythmogenic. Arpromidine may be considered a new lead for the development of "cardiohistaminergics". In the arpromidine series the order of potency found in guinea-pig atria was in good agreement with the results from isolated perfused guinea-pig hearts. In particular, the two-fold halogenated arpromidine analogues proved to be more potent positive inotropic agents than impromidine with lower stimulating effects on heart rate and reduced arrhythmogenic properties.

Piprinhydrinate is compositon of Diphenylpyraline and 8-chloroteophylline. 8-Chlorotheophylline is a stimulant drug of the xanthine chemical class, with physiological effects similar to caffeine. Diphenylpyraline is an antihistamine that prevents, but does not reverse, responses mediated by histamine alone. Diphenylpyraline antagonizes most of the pharmacological effects of histamine, including urticaria and pruritus. Also, diphenylpyraline may exhibit anticholinergic actions (as do most of the antihistamines) and may thus provide a drying effect on the nasal mucosa. 8-Chlorotheophylline main use is in combination with Diphenylpyraline or diphenhydramine in the antiemetic Piprinhydrinate and dimenhydrinate. Diphenylpyraline (or diphenhydramine) reduces nausea but causes drowsiness, and the stimulant properties of 8-Chlorotheophylline help ward off that side-effect.

Histapyrrodine was investigated as a neuro-sedative drug for the treatment of anxiety and states of aggression.

Zepastine is antihistamine antiallergic drug developed in the late 1960-s.

Homochlorcyclizine (INN) is an antihistamine which has been marketed in Japan since 1965. It is used in the treatment of Itching sensation resulting from skin diseases (eczema or dermatitis, pruritus, drug eruption, toxic erythema and infant strophulus), urticaria and allergic rhinitis. Homochlorcyclizine hydrochloride possesses several pharmacological properties: 1) inhibits bradykinin-induced contractions of isolated guinea pig ileum; 2)partially blocks SRS-A (slow-reacting substance of anaphylaxis )- induced contractions in isolated guinea pig il eum. 3) Homochlorcyclizine hydrochloride completely inhibits histamine-induced contractions at a concentration of 0.1μg/mL, while it completely inhibits serotonin or acetylcholine- induced contractions at a concentration of 1μg/mL.