PARATHIAZINE, a member of phenothiazines, is a histamine receptor antagonist used for the treatment of allergic diseases. Also, it can be used as an antiemetic agent.

Pyrabrom (also known as mepyramine 8-bromotheophyllinate) is a pharmaceutical preparation that causes antidiuresis under conditions of water load. However, under conditions of salt load Pyrabrom increases the speed of urinary excretion.

Tripelennamine (sold as Pyribenzamine by Novartis) is a drug that is used as an antipruritic and first-generation antihistamine. Histamine acting on H1-receptors produces vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Tripelennamine can be used in the treatment of asthma, hay fever, rhinitis, and urticaria, but is now less common as newer antihistamines have replaced it.

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.

Chlorothen citrate (trade name Tagathen) is an antihistamine and a first generation H1 receptor antagonist, that have been used for the treatment of asthma, bronchitis, and bronchoconstriction.‘-5. Chlorothen is synthesized by condensation of 5-chloro-2-thienylchloride and N,N-dimethyl-N-(2-pyridinyl)ethylenediamine in the presence of sodium or potassium amide

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.

Cannabinol is a cannabinoid isolated from the plant Cannabis that is a metabolite of tetrahydrocannabinol (THC), with potential immunosuppressive and anti-inflammatory activities. Cannabinol acts as a partial agonist at the CB1 receptors, but it preferentially binds to the cannabinoid G-protein coupled receptor CB2, which is mainly expressed on a variety of immune cells, such as T-cells, B-cells, macrophages and dendritic cells. Stimulation of CB2 receptors by cannabinol may both trigger apoptosis in these cells and inhibit the production of a variety of cytokines. In the United States, federal and state laws regarding the legality of cannabis products are confusing and at times contradictory. CBN is not listed in the list of scheduled controlled substances in the USA.

Golotimod (SCV-07) is compound that has been investigated as a medicine for the treatment of tuberculosis, and various other viral and bacterial infections. Golotimod acts broadly on the Toll-like receptor (TLR) pathway. It stimulates the T-helper 1 (Th1) type immune response and blocks signal transducers and activator of transcription 3 (STAT3) mediated signaling. Treatment of tuberculosis with golotimod improves clearance of mycobacteria, cavity healing, and immune parameters and also reduced symptoms (such as fever, weakness, sweating, dry cough, productive cough, dyspnea, chest pain, tachycardia) without adverse effects. Phase II clinical trials have been completed to assess its safety and tolerability.

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.