Anti-histamine drugs

M2 receptor antagonists may also be used for the treatment of Alzheimer s disease, furthermore in the therapy of supraventricular bradycardia and for quantifying M2 receptors in the CNS with PET imaging. In the search for antagonists which clearly differentiate M2 from other muscarinic receptors, we investigated the two enantiomers of the widely used Hj-anti-histaminic drug dimethindene. (S)-Dimethindene proved to be a potent M2-selective antagonist with lower affinities for the Mj, M3 and M4 receptors. In addition, the (S)-enantiomer... 

The concept of an endogenous mediator of increased permeability was supported by the classical studies of Lewis on histamine. The increase in vascular permeability is a biphasic process, the earlier transient stage, in some species at least, resulting from the release of histamine. After suitable mild inflammatory stimuli, the tissue oedema may often be inhibited by anti-histaminic drugs. In a limited sense, therefore, antihistaminic drugs may be regarded as having anti-inflammatory activity, but they are not discussed in detail in this review. 

It was soon found that excellent anti-histaminic drugs could be based on ethanolamine instead of ethylenediamine and a notable example from the United States was diphenhydramine (9.56) ( Benadryl ). Members of this class couple their anti-histaminic effect with sedative properties and are prescribed when a high degree of somnolence is advantageous. There is only one ionizing group (pA 9.0). 

For a discussion of the steric contribution to the action of Hi anti-histaminic drugs, see Casy and Ison (1970) and for a more general discussion, see Rocha e Silva 0978). 

For discussion of anti-histaminic drugs, see the volume edited by Rocha e Silva (1978). 

Acetylcholine has the same conformation in aqueous solution (as determined by n.m.r. in D2O) as in the solid state (as determined by X-ray crystallography) (see Section 12.6). How widely does this correlation extend Byrn, Graberand Midland (1976) have reviewed the literature on this and, as X-ray diffraction analysis is exceedingly slow, they have devised a simple test the infrared spectrum in the solid state is compared with that in chloroform. Although this test requires further examination, it is worth recording that they found very similar infrared spectra under both conditions for choline chloride and for the anti-histaminic drug, methapyrilene, whereas they found very different spectra for histamine and for the anti-histaminic drug, diphenhydramine. 

Figure 8.7 Examples of anti-inflammatory and anti-histaminic drugs containing a-aryl carboxylic acid units.

More typical examples are the amino ethers (3) used as anti-histamine or anti-Parkinson drugs according to the substituents. These are obviously derived from the alcohols (4) which are made from an aryl Grignard reagent and a benzaldehyde. Either starting material may bear the substituent X the choice can be made according to availability and so that side reactions are avoided,... 

Contrary to other elicitors of non-immune anaphylactic reactions (radiocontrast media, neuromuscular blocking agents, non-steroidal anti-inflammatory drugs (NSAIDs)) where there are at least hypothetical concepts regarding the pathomecha-nism of these reactions via increased mediator release (e.g. histamine release, shift in arachidonic acid metabolism from prostaglandins towards leukotrienes, etc.) [26], there is almost no literature regarding the pathomechanism of these reactions after LA application. 

Tricyclic anti-depressive drugs 520 Trimeprazine base e29 Trimethylamine, ornithine, amines, histamine, hypoxanthine 257 Trinitrocompounds 877 TSM 815 Tumour cell 102 Turnover number 919 Tween 20 808, 814 Two-photon effect 100... 

During the Second World War, Union Chimique Beige started producing basic pharmaceuticals such as calcium, phosphor, vitamins, insulin, and sulfamides. However, it was only in the late fifties that it launched, with limited market impact, its first real pharmaceutical products - Postafene (an anti-histamine), Atarax (a tranquilizer) and Tuclase (a cough and cold drug) - and concluded a first license agreement with Pfizer for the distribution of Atarax in the U.S. 

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