Antazoline is an antagonist of histamine H1 receptors. It selectively bind to but does not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine. Antazoline in combination with naphazoline (VASOCON-A®) is indicated to relieve the symptoms of allergic conjunctivitis.

Thimerosal is organomercury antiseptic and antifungal agent, used as a preservative in vaccines, immuloglobulins, nasal sprays, contact lens solutions. In USA, European Union countries thiomersal is no longer used in childhood vaccines due to public fears, although the FDA review of 1999 foud no evidence of harm from the use of thimerosal as a vaccine preservative, other than local hypersensitivity reactions. Thimerosal was used as a component of topical antiseptic solution and antiseptic ointment for treating cuts, nasal sprays, eye solutions, vaginal spermicides, diaper rash treatments, but re-evaluation of the drug in 1980-s demonstrated ineffectiveness and toxicity in topical pharmaceutical products, and topical thimerosal was withdrawn from the market. The mechanism of action of thimerosal has not been fully elucidated. It is believed that thimerosal inhibits sulfhydryl-containing active site of various enzymes and binds to sulfhydryl compounds, such as glutathione, cysteine, and SH groups of protein. In addition, thimerosal activates the InsP3 calcium channel on endoplasmic reticular membrane, thereby triggering the release of calcium from intracellular stores resulting in a calcium-induced calcium-influx of extracellular calcium. Consequently, thimerosal may induce or inhibit cellular functions dependent on calcium signaling.

Methapyrilene is an antihistamine and anticholinergic of the pyridine chemical class which was developed in the early 1950s. It was sold under the trade names Co-Pyronil and Histadyl EC. It has relatively strong sedative effects, to the extent that its primary use was as a medication for insomnia rather than for its antihistamine action. Together with scopolamine, it was the main ingredient in Sominex, Nytol, and Sleep-Eze. It also provided the sedative component of Excedrin PM. Manufacturers voluntarily withdrew methapyrilineb drug products from the market in May and June 1979, when methapyrilene was demonstrated to cause liver cancer in rats when given chronically.

Methapyrilene is an antihistamine and anticholinergic of the pyridine chemical class which was developed in the early 1950s. It was sold under the trade names Co-Pyronil and Histadyl EC. It has relatively strong sedative effects, to the extent that its primary use was as a medication for insomnia rather than for its antihistamine action. Together with scopolamine, it was the main ingredient in Sominex, Nytol, and Sleep-Eze. It also provided the sedative component of Excedrin PM. Manufacturers voluntarily withdrew methapyrilineb drug products from the market in May and June 1979, when methapyrilene was demonstrated to cause liver cancer in rats when given chronically.

There is not much available information about thenyldiamine, is known, that it is used as antihistamine and for the treatment of asthma and bronchitis.

Cloperastine (INN) or cloperastin is an antitussive and antihistamine that is marketed as a cough suppressant in Japan, Hong Kong, and in some European countries. It was first introduced in 1972 in Japan, and then in Italy in 1981. The precise mechanism of action of cloperastine is not fully clear, but several different biological activities have been identified for the drug, of which include: ligand of the gamma1 receptor (Ki = 20 nM) (likely an agonist), GIRK channel blocker (described as "potent"), antihistamine (Ki = 3.8 nM for the H1 receptor), and anticholinergic. Cloperastine possesses dual activity. It also acts as a mild bronchorelaxant and has antihistaminic activity, without acting on the central nervous system or the respiratory center.

Cloperastine (INN) or cloperastin is an antitussive and antihistamine that is marketed as a cough suppressant in Japan, Hong Kong, and in some European countries. It was first introduced in 1972 in Japan, and then in Italy in 1981. The precise mechanism of action of cloperastine is not fully clear, but several different biological activities have been identified for the drug, of which include: ligand of the gamma1 receptor (Ki = 20 nM) (likely an agonist), GIRK channel blocker (described as "potent"), antihistamine (Ki = 3.8 nM for the H1 receptor), and anticholinergic. Cloperastine possesses dual activity. It also acts as a mild bronchorelaxant and has antihistaminic activity, without acting on the central nervous system or the respiratory center.

Thiazinamium is an anti-cholinergic phenothiazine deriva¬tive, which also has antihistaminic properties. Intramuscular injection of Thiazinamium induces considerable bronchodilatation, but inconsistent results have been obtained after oral administration. The bioavailability of oral Thiazinamium is only 2-3% of that occurring after intramuscular injection. Intrarectal Thiazinamium is slightly better absorbed (3-9%). The elimination half-life of the parenteral drug is short, being about 20 minutes in most patients. Thiazinamium has been available for the treatment of asthma since the early 1960s but currently withdrawn in most countries. Compared with inhaled ipratropium bromide, intramuscular Thiazinamium and intramuscular atropine were associated with 'extremely frequent side-effects’. Notable tachycardia occurred shortly after intramuscular injection of Thiazinamium in two trials. Dry mouth was reported as ‘frequent’ with oral Thiazinamium, and micturition problems of moderate severity affected 13% of patients.

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.

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.