Antihistamine

Last updated

Antihistamine
Drug class
Histamine.svg
Histamine structure
Class identifiers
Pronunciation /ˌæntiˈhɪstəmn/
ATC code R06
Mechanism of action   Receptor antagonist
  Inverse agonist
Biological target Histamine receptors
  HRH1
  HRH2
  HRH3
  HRH4
External links
MeSH D006633
Legal status
In Wikidata

Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. [1] Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides relief from nasal congestion, sneezing, or hives caused by pollen, dust mites, or animal allergy with few side effects. [1] Antihistamines are usually for short-term treatment. [1] Chronic allergies increase the risk of health problems which antihistamines might not treat, including asthma, sinusitis, and lower respiratory tract infection. [1] Consultation of a medical professional is recommended for those who intend to take antihistamines for longer-term use. [1]

Contents

Although the general public typically uses the word "antihistamine" to describe drugs for treating allergies, physicians and scientists use the term to describe a class of drug that opposes the activity of histamine receptors in the body. [2] In this sense of the word, antihistamines are subclassified according to the histamine receptor that they act upon. The two largest classes of antihistamines are H1-antihistamines and H2-antihistamines.

H1-antihistamines work by binding to histamine H1 receptors in mast cells, smooth muscle, and endothelium in the body as well as in the tuberomammillary nucleus in the brain. Antihistamines that target the histamine H1-receptor are used to treat allergic reactions in the nose (e.g., itching, runny nose, and sneezing). In addition, they may be used to treat insomnia, motion sickness, or vertigo caused by problems with the inner ear. H2-antihistamines bind to histamine H2 receptors in the upper gastrointestinal tract, primarily in the stomach. Antihistamines that target the histamine H2-receptor are used to treat gastric acid conditions (e.g., peptic ulcers and acid reflux). Other antihistamines also target H3 receptors and H4 receptors.

Histamine receptors exhibit constitutive activity, so antihistamines can function as either a neutral receptor antagonist or an inverse agonist at histamine receptors. [2] [3] [4] [5] Only a few currently marketed H1-antihistamines are known to function as inverse agonists. [2] [5]

Medical uses

Histamine makes blood vessels more permeable (vascular permeability), causing fluid to escape from capillaries into tissues, which leads to the classic symptoms of an allergic reaction — a runny nose and watery eyes. Histamine also promotes angiogenesis. [6]

Antihistamines suppress the histamine-induced wheal response (swelling) and flare response (vasodilation) by blocking the binding of histamine to its receptors or reducing histamine receptor activity on nerves, vascular smooth muscle, glandular cells, endothelium, and mast cells. Antihistamines can also help correct Eustachian Tube dysfunction, thereby helping correct problems such as muffled hearing, fullness in the ear and even tinnitus. [7]

Itching, sneezing, and inflammatory responses are suppressed by antihistamines that act on H1-receptors. [2] [8] In 2014, antihistamines such as desloratadine were found to be effective to complement standardized treatment of acne due to their anti-inflammatory properties and their ability to suppress sebum production. [9] [10]

Types

H1-antihistamines

H1-antihistamines refer to compounds that inhibit the activity of the H1 receptor. [4] [5] Since the H1 receptor exhibits constitutive activity, H1-antihistamines can be either neutral receptor antagonists or inverse agonists. [4] [5] Normally, histamine binds to the H1 receptor and heightens the receptor's activity; the receptor antagonists work by binding to the receptor and blocking the activation of the receptor by histamine; by comparison, the inverse agonists bind to the receptor and both block the binding of histamine, and reduce its constitutive activity, an effect which is opposite to histamine's. [4] Most antihistamines are inverse agonists at the H1 receptor, but it was previously thought that they were antagonists. [11]

Clinically, H1-antihistamines are used to treat allergic reactions and mast cell-related disorders. Sedation is a common side effect of H1-antihistamines that readily cross the blood–brain barrier; some of these drugs, such as diphenhydramine and doxylamine, may therefore be used to treat insomnia. H1-antihistamines can also reduce inflammation, since the expression of NF-κB, the transcription factor the regulates inflammatory processes, is promoted by both the receptor's constitutive activity and agonist (i.e., histamine) binding at the H1 receptor. [2]

A combination of these effects, and in some cases metabolic ones as well, lead to most first-generation antihistamines having analgesic-sparing (potentiating) effects on opioid analgesics and to some extent with non-opioid ones as well. The most common antihistamines utilized for this purpose include hydroxyzine, promethazine (enzyme induction especially helps with codeine and similar prodrug opioids), phenyltoloxamine, orphenadrine, and tripelennamine; some may also have intrinsic analgesic properties of their own, orphenadrine being an example.

Second-generation antihistamines cross the blood–brain barrier to a much lesser extent than the first-generation antihistamines. They minimize sedatory effects due to their focused effect on peripheral histamine receptors. However, upon high doses second-generation antihistamines will begin to act on the central nervous system and thus can induce drowsiness when ingested in higher quantity.

List of H1 antagonists/inverse agonists

H2-antihistamines

H2-antihistamines, like H1-antihistamines, exist as inverse agonists and neutral antagonists. They act on H2 histamine receptors found mainly in the parietal cells of the gastric mucosa, which are part of the endogenous signaling pathway for gastric acid secretion. Normally, histamine acts on H2 to stimulate acid secretion; drugs that inhibit H2 signaling thus reduce the secretion of gastric acid.

H2-antihistamines are among first-line therapy to treat gastrointestinal conditions including peptic ulcers and gastroesophageal reflux disease. Some formulations are available over the counter. Most side effects are due to cross-reactivity with unintended receptors. Cimetidine, for example, is notorious for antagonizing androgenic testosterone and DHT receptors at high doses.

Examples include:

H3-antihistamines

An H3-antihistamine is a classification of drugs used to inhibit the action of histamine at the H3 receptor. H3 receptors are primarily found in the brain and are inhibitory autoreceptors located on histaminergic nerve terminals, which modulate the release of histamine. Histamine release in the brain triggers secondary release of excitatory neurotransmitters such as glutamate and acetylcholine via stimulation of H1 receptors in the cerebral cortex. Consequently, unlike the H1-antihistamines which are sedating, H3-antihistamines have stimulant and cognition-modulating effects.

Examples of selective H3-antihistamines include:

H4-antihistamines

H4-antihistamines inhibit the activity of the H4 receptor. Examples:

Atypical antihistamines

Histidine decarboxylase inhibitors

Inhibit the action of histidine decarboxylase:

Mast cell stabilizers

Mast cell stabilizers are drugs which prevent mast cell degranulation.

History

The first H1 receptor antagonists were discovered in the 1930s and were marketed in the 1940s. [17] Piperoxan was discovered in 1933 and was the first compound with antihistamine effects to be identified. [17] Piperoxan and its analogues were too toxic to be used in humans. [17] Phenbenzamine (Antergan) was the first clinically useful antihistamine and was introduced for medical use in 1942. [17] Subsequently, many other antihistamines were developed and marketed. [17] Diphenhydramine (Benadryl) was synthesized in 1943, tripelennamine (Pyribenzamine) was patented in 1946, and promethazine (Phenergan) was synthesized in 1947 and launched in 1949. [17] [18] [19] By 1950, at least 20 antihistamines had been marketed. [20] Chlorphenamine (Piriton), a less sedating antihistamine, was synthesized in 1951, and hydroxyzine (Atarax, Vistaril), an antihistamine used specifically as a sedative and tranquilizer, was developed in 1956. [17] [21] The first non-sedating antihistamine was terfenadine (Seldane) and was developed in 1973. [17] [22] Subsequently, other non-sedating antihistamines like loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) were developed and introduced. [17]

The introduction of the first-generation antihistamines marked the beginning of medical treatment of nasal allergies. [23] Research into these drugs led to the discovery that they were H1 receptor antagonists and also to the development of H2 receptor antagonists, where H1-antihistamines affected the nose and the H2-antihistamines affected the stomach. [24] This history has led to contemporary research into drugs which are H3 receptor antagonists and which affect the H4 receptor antagonists. [24] Most people who use an H1 receptor antagonist to treat allergies use a second-generation drug. [1]

Society and culture

The United States government removed two second generation antihistamines, terfenadine and astemizole, from the market based on evidence that they could cause heart problems. [1]

Research

Not much published research exists which compares the efficacy and safety of the various antihistamines available. [1] The research which does exist is mostly short-term studies or studies which look at too few people to make general assumptions. [1] Another gap in the research is in information reporting the health effects for individuals with long-term allergies who take antihistamines for a long period of time. [1] Newer antihistamines have been demonstrated to be effective in treating hives. [1] However, there is no research comparing the relative efficacy of these drugs. [1]

Special populations

In 2020, the UK National Health Service wrote that "[m]ost people can safely take antihistamines" but that "[s]ome antihistamines may not be suitable" for young children, the pregnant or breastfeeding, for those taking other medicines, or people with conditions "such as heart disease, liver disease, kidney disease or epilepsy". [25]

Most studies of antihistamines reported on people who are younger, so the effects on people over age 65 are not as well understood. [1] Older people are more likely to experience drowsiness from antihistamine use than younger people. [1] Continuous and/or cumulative use of anticholinergic medications, including first-generation antihistamines, is associated with higher risk for cognitive decline and dementia in older people. [26] [27]

Also, most of the research has been on caucasians and other ethnic groups are not as represented in the research. [1] The evidence does not report how antihistamines affect women differently than men. [1] Different studies have reported on antihistamine use in children, with various studies finding evidence that certain antihistamines could be used by children 2 years of age, and other drugs being safer for younger or older children. [1]

Potential uses studied

Research regarding the effects of commonly used medications upon certain cancer therapies has suggested that when consumed in conjunction with immune checkpoint inhibitors some may influence the response of subjects to that particular treatment whose T-cell functions were failing in anti-tumor activity. Upon study of records in mouse studies associated with 40 common medications ranging from antibiotics, antihistamines, aspirin, and hydrocortisone, that for subjects with melanoma and lung cancers, fexofenadine, one of three medications, along with loratadine, and cetirizine, that target histamine receptor H1 (HRH1), demonstrated significantly higher survival rates and had experienced restored T-cell anti-tumor activity, ultimately inhibiting tumor growth in the subject animals. [28] Such results encourage further study in order to see whether results in humans is similar in combating resistance to immunotherapy.

See also

Related Research Articles

<span class="mw-page-title-main">Tricyclic antidepressant</span> Class of medications

Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants. TCAs were discovered in the early 1950s and were marketed later in the decade. They are named after their chemical structure, which contains three rings of atoms. Tetracyclic antidepressants (TeCAs), which contain four rings of atoms, are a closely related group of antidepressant compounds.

<span class="mw-page-title-main">Tetracyclic antidepressant</span> Class of pharmaceutical drugs

Tetracyclic antidepressants (TeCAs) are a class of antidepressants that were first introduced in the 1970s. They are named after their tetracyclic chemical structure, containing four rings of atoms, and are closely related to the tricyclic antidepressants (TCAs), which contain three rings of atoms.

H<sub>2</sub> receptor antagonist Class of medications

H2 antagonists, sometimes referred to as H2RAs and also called H2 blockers, are a class of medications that block the action of histamine at the histamine H2 receptors of the parietal cells in the stomach. This decreases the production of stomach acid. H2 antagonists can be used in the treatment of dyspepsia, peptic ulcers and gastroesophageal reflux disease. They have been surpassed by proton pump inhibitors (PPIs). The PPI omeprazole was found to be more effective at both healing and alleviating symptoms of ulcers and reflux oesophagitis than the H2 blockers ranitidine and cimetidine.

<span class="mw-page-title-main">Histamine</span> Organic compound involved in immune responses

Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered in 1910, it has been considered a local hormone (autocoid) because it lacks the classic endocrine glands to secrete it; however, in recent years, histamine has been recognized as a central neurotransmitter. Histamine is involved in the inflammatory response and has a central role as a mediator of itching. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues. It consists of an imidazole ring attached to an ethylamine chain; under physiological conditions, the amino group of the side-chain is protonated.

H1 antagonists, also called H1 blockers, are a class of medications that block the action of histamine at the H1 receptor, helping to relieve allergic reactions. Agents where the main therapeutic effect is mediated by negative modulation of histamine receptors are termed antihistamines; other agents may have antihistaminergic action but are not true antihistamines.

<span class="mw-page-title-main">Diphenhydramine</span> Antihistamine medication

Diphenhydramine (DPH) is an antihistamine and sedative mainly used to treat allergies, insomnia, and symptoms of the common cold. It is also less commonly used for tremors in parkinsonism, and nausea. It is taken by mouth, injected into a vein, injected into a muscle, or applied to the skin. Maximal effect is typically around two hours after a dose, and effects can last for up to seven hours.

<span class="mw-page-title-main">Mirtazapine</span> Antidepressant medication

Mirtazapine, sold under the brand name Remeron among others, is an atypical tetracyclic antidepressant, and as such is used primarily to treat depression. Its effects may take up to four weeks, but can also manifest as early as one to two weeks. It is often used in cases of depression complicated by anxiety or insomnia. The effectiveness of mirtazapine is comparable to other commonly prescribed antidepressants. It is taken by mouth.

<span class="mw-page-title-main">Receptor antagonist</span> Type of receptor ligand or drug that blocks a biological response

A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins. They are sometimes called blockers; examples include alpha blockers, beta blockers, and calcium channel blockers. In pharmacology, antagonists have affinity but no efficacy for their cognate receptors, and binding will disrupt the interaction and inhibit the function of an agonist or inverse agonist at receptors. Antagonists mediate their effects by binding to the active site or to the allosteric site on a receptor, or they may interact at unique binding sites not normally involved in the biological regulation of the receptor's activity. Antagonist activity may be reversible or irreversible depending on the longevity of the antagonist–receptor complex, which, in turn, depends on the nature of antagonist–receptor binding. The majority of drug antagonists achieve their potency by competing with endogenous ligands or substrates at structurally defined binding sites on receptors.

<span class="mw-page-title-main">Chlorphenamine</span> Antihistamine used to treat allergies

Chlorphenamine, also known as chlorpheniramine, is an antihistamine used to treat the symptoms of allergic conditions such as allergic rhinitis. It is taken orally. The medication takes effect within two hours and lasts for about 4–6 hours. It is a first-generation antihistamine and works by blocking the H1 receptor.

<span class="mw-page-title-main">Hydroxyzine</span> Antihistamine drug

Hydroxyzine, sold under the brand names Atarax and Vistaril among others, is an antihistamine medication. It is used in the treatment of itchiness, insomnia, anxiety, and nausea, including that due to motion sickness. It is used either by mouth or injection into a muscle.

The histamine receptors are a class of G protein–coupled receptors which bind histamine as their primary endogenous ligand.

<span class="mw-page-title-main">Desloratadine</span> Allergy medication

Desloratadine (trade names Clarinex and Aerius) is a tricyclic H1 inverse agonist that is used to treat allergies. It is an active metabolite of loratadine.

<span class="mw-page-title-main">Amoxapine</span> Tricyclic antidepressant medication

Amoxapine, sold under the brand name Asendin among others, is a tricyclic antidepressant (TCA). It is the N-demethylated metabolite of loxapine. Amoxapine first received marketing approval in the United States in 1980, approximately 10 to 20 years after most of the other TCAs were introduced in the United States.

<span class="mw-page-title-main">Doxepin</span> Medication to treat depressive disorder, anxiety disorders, chronic hives, and trouble sleeping

Doxepin is a medication belonging to the tricyclic antidepressant (TCA) class of drugs used to treat major depressive disorder, anxiety disorders, chronic hives, and insomnia. For hives it is a less preferred alternative to antihistamines. It has a mild to moderate benefit for sleeping problems. It is used as a cream for itchiness due to atopic dermatitis or lichen simplex chronicus.

Histamine H<sub>3</sub> receptor Mammalian protein found in Homo sapiens

Histamine H3 receptors are expressed in the central nervous system and to a lesser extent the peripheral nervous system, where they act as autoreceptors in presynaptic histaminergic neurons and control histamine turnover by feedback inhibition of histamine synthesis and release. The H3 receptor has also been shown to presynaptically inhibit the release of a number of other neurotransmitters (i.e. it acts as an inhibitory heteroreceptor) including, but probably not limited to dopamine, GABA, acetylcholine, noradrenaline, histamine and serotonin.

<span class="mw-page-title-main">Chlorprothixene</span> Typical antipsychotic medication

Chlorprothixene, sold under the brand name Truxal among others, is a typical antipsychotic of the thioxanthene group.

Histamine H<sub>1</sub> receptor Histamine receptor

The H1 receptor is a histamine receptor belonging to the family of rhodopsin-like G-protein-coupled receptors. This receptor is activated by the biogenic amine histamine. It is expressed in smooth muscles, on vascular endothelial cells, in the heart, and in the central nervous system. The H1 receptor is linked to an intracellular G-protein (Gq) that activates phospholipase C and the inositol triphosphate (IP3) signalling pathway. Antihistamines, which act on this receptor, are used as anti-allergy drugs. The crystal structure of the receptor has been determined (shown on the right/below) and used to discover new histamine H1 receptor ligands in structure-based virtual screening studies.

<span class="mw-page-title-main">Chloropyramine</span> Chemical compound

Chloropyramine is a classical first-generation antihistamine drug approved in Eastern European countries for the treatment of allergic conjunctivitis, allergic rhinitis, bronchial asthma, and other atopic (allergic) conditions. Related indications for clinical use include angioedema, allergic reactions to insect bites, food and drug allergies, and anaphylactic shock.

<span class="mw-page-title-main">Mianserin</span> Antidepressant

Mianserin, sold under the brand name Tolvon among others, is an atypical antidepressant that is used primarily in the treatment of depression in Europe and elsewhere in the world. It is a tetracyclic antidepressant (TeCA). Mianserin is closely related to mirtazapine, both chemically and in terms of its actions and effects, although there are significant differences between the two drugs.

An H3 receptor antagonist is a type of antihistaminic drug used to block the action of histamine at H3 receptors.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Consumer Reports (2013), Using Antihistamines to Treat Allergies, Hay Fever, & Hives - Comparing Effectiveness, Safety, and Price (PDF), Yonkers, New York: Consumer Reports, archived from the original (PDF) on 17 May 2017, retrieved 29 June 2017
  2. 1 2 3 4 5 Canonica GW, Blaiss M (2011). "Antihistaminic, anti-inflammatory, and antiallergic properties of the nonsedating second-generation antihistamine desloratadine: a review of the evidence". World Allergy Organ J. 4 (2): 47–53. doi:10.1097/WOX.0b013e3182093e19. PMC   3500039 . PMID   23268457. The H1-receptor is a transmembrane protein belonging to the G-protein coupled receptor family. Signal transduction from the extracellular to the intracellular environment occurs as the GCPR becomes activated after binding of a specific ligand or agonist. A subunit of the G-protein subsequently dissociates and affects intracellular messaging including downstream signaling accomplished through various intermediaries such as cyclic AMP, cyclic GMP, calcium, and nuclear factor kappa B (NF-κB), a ubiquitous transcription factor thought to play an important role in immune-cell chemotaxis, proinflammatory cytokine production, expression of cell adhesion molecules, and other allergic and inflammatory conditions.1,8,12,30–32 ... For example, the H1-receptor promotes NF-κB in both a constitutive and agonist-dependent manner and all clinically available H1-antihistamines inhibit constitutive H1-receptor-mediated NF-κB production ...
    Importantly, because antihistamines can theoretically behave as inverse agonists or neutral antagonists, they are more properly described as H1-antihistamines rather than H1-receptor antagonists.15
  3. Panula P, Chazot PL, Cowart M, et al. (2015). "International Union of Basic and Clinical Pharmacology. XCVIII. Histamine Receptors". Pharmacol. Rev. 67 (3): 601–55. doi:10.1124/pr.114.010249. PMC   4485016 . PMID   26084539.
  4. 1 2 3 4 Leurs R, Church MK, Taglialatela M (April 2002). "H1-antihistamines: inverse agonism, anti-inflammatory actions and cardiac effects". Clinical and Experimental Allergy. 32 (4): 489–98. doi:10.1046/j.0954-7894.2002.01314.x. PMID   11972592. S2CID   11849647.
  5. 1 2 3 4 "H1 receptor". IUPHAR/BPS Guide to Pharmacology. Retrieved 8 October 2015.
  6. Norrby K (1995). "Evidence of a dual role of endogenous histamine in angiogenesis". Int J Exp Pathol. 76 (2): 87–92. PMC   1997159 . PMID   7540412.
  7. "Best Antihistamine for Tinnitus?". Tinnitus and You. 28 September 2021. Retrieved 15 March 2022.
  8. Monroe EW, Daly AF, Shalhoub RF (February 1997). "Appraisal of the validity of histamine-induced wheal and flare to predict the clinical efficacy of antihistamines". The Journal of Allergy and Clinical Immunology. 99 (2): S798–806. doi: 10.1016/s0091-6749(97)70128-3 . PMID   9042073.
  9. Lee HE, Chang IK, Lee Y, Kim CD, Seo YJ, Lee JH, Im M (2014). "Effect of antihistamine as an adjuvant treatment of isotretinoin in acne: a randomized, controlled comparative study". J Eur Acad Dermatol Venereol. 28 (12): 1654–60. doi:10.1111/jdv.12403. PMID   25081735. S2CID   3406128.
  10. Layton AM (2016). "Top Ten List of Clinical Pearls in the Treatment of Acne Vulgaris". Dermatol Clin. 34 (2): 147–57. doi:10.1016/j.det.2015.11.008. PMID   27015774.
  11. Church, Diana S; Church, Martin K (15 March 2011). "Pharmacology of Antihistamines". The World Allergy Organization Journal. 4 (Suppl 3): S22–S27. doi:10.1097/1939-4551-4-S3-S22. ISSN   1939-4551. PMC   3666185 . PMID   23282332.
  12. Thomas L. Lemke; David A. Williams, eds. (24 January 2012). Foye's Principles of Medicinal Chemistry. Lippincott Williams & Wilkins. pp. 1053–. ISBN   978-1-60913-345-0. OCLC   1127763671.
  13. Yoneyama H, et al. (March 2008). "Efficient approaches to S-alkyl-N-alkylisothioureas: syntheses of histamine H3 antagonist clobenpropit and its analogues". The Journal of Organic Chemistry. 73 (6): 2096–104. doi:10.1021/jo702181x. PMID   18278935.
  14. Fox GB, Esbenshade TA, Pan JB, Radek RJ, Krueger KM, Yao BB, Browman KE, Buckley MJ, Ballard ME, Komater VA, Miner H, Zhang M, Faghih R, Rueter LE, Bitner RS, Drescher KU, Wetter J, Marsh K, Lemaire M, Porsolt RD, Bennani YL, Sullivan JP, Cowart MD, Decker MW, Hancock AA (April 2005). "Pharmacological properties of ABT-239 [4-(2-{2-[(2R)-2-Methylpyrrolidinyl]ethyl}-benzofuran-5-yl)benzonitrile]: II. Neurophysiological characterization and broad preclinical efficacy in cognition and schizophrenia of a potent and selective histamine H3 receptor antagonist". The Journal of Pharmacology and Experimental Therapeutics. 313 (1): 176–90. doi:10.1124/jpet.104.078402. PMID   15608077. S2CID   15430117.
  15. Ligneau X, Lin J, Vanni-Mercier G, Jouvet M, Muir JL, Ganellin CR, Stark H, Elz S, Schunack W, Schwartz J (November 1998). "Neurochemical and behavioral effects of ciproxifan, a potent histamine H3-receptor antagonist". The Journal of Pharmacology and Experimental Therapeutics. 287 (2): 658–66. PMID   9808693. Archived from the original on 2 May 2020. Retrieved 9 August 2014.
  16. Esbenshade TA, Fox GB, Krueger KM, Baranowski JL, Miller TR, Kang CH, Denny LI, Witte DG, Yao BB, Pan JB, Faghih R, Bennani YL, Williams M, Hancock AA (September 2004). "Pharmacological and behavioral properties of A-349821, a selective and potent human histamine H3 receptor antagonist". Biochemical Pharmacology. 68 (5): 933–45. doi:10.1016/j.bcp.2004.05.048. PMID   15294456.
  17. 1 2 3 4 5 6 7 8 9 Ralph Landau; Basil Achilladelis; Alexander Scriabine (1999). Pharmaceutical Innovation: Revolutionizing Human Health. Chemical Heritage Foundation. pp. 230–. ISBN   978-0-941901-21-5.
  18. David Healy (July 2009). The Creation of Psychopharmacology. Harvard University Press. pp. 77–. ISBN   978-0-674-03845-5.
  19. János Fischer; C. Robin Ganellin (24 August 2010). Analogue-based Drug Discovery II. John Wiley & Sons. pp. 36–. ISBN   978-3-527-63212-1.
  20. Moncrieff, Joanna (2013). "Chlorpromazine: The First Wonder Drug". The Bitterest Pills. Palgrave Macmillan UK. pp. 20–38. doi:10.1057/9781137277442_2. ISBN   978-1-137-27743-5.
  21. Atta-ur-Rahman (11 July 2018). Frontiers in Clinical Drug Research - Anti-Allergy Agents. Bentham Science Publishers. pp. 31–. ISBN   978-1-68108-337-7.
  22. Walter Sneader (31 October 2005). Drug Discovery: A History. John Wiley & Sons. pp. 406–. ISBN   978-0-470-01552-0.
  23. Ostrom, NK (2014). "The history and progression of treatments for allergic rhinitis". Allergy and Asthma Proceedings. 35 Suppl 1 (3): S3–10. doi:10.2500/aap.2014.35.3758. PMID   25582156.
  24. 1 2 Jones, AW (January 2016). "Perspectives in Drug Development and Clinical Pharmacology: The Discovery of Histamine H1 and H2 Antagonists". Clinical Pharmacology in Drug Development. 5 (1): 5–12. doi:10.1002/cpdd.236. PMID   27119574. S2CID   29402462.
  25. "Antihistamines". NHS . 28 February 2020. Archived from the original on 22 December 2017. Retrieved 28 April 2021.
  26. Gray SL, Anderson ML, Dublin S, Hanlon JT, Hubbard R, Walker R, et al. (March 2015). "Cumulative use of strong anticholinergics and incident dementia: a prospective cohort study". JAMA Internal Medicine. 175 (3): 401–407. doi:10.1001/jamainternmed.2014.7663. PMC   4358759 . PMID   25621434.
  27. Carrière, I; Fourrier-Reglat, A; Dartigues, J-F; Rouaud, O; Pasquier, F; Ritchie, K; Ancelin, M-L (July 2009). "Drugs with anticholinergic properties, cognitive decline, and dementia in an elderly general population: the 3-city study". Archives of Internal Medicine. 169 (14): 1317–1324. doi:10.1001/archinternmed.2009.229. PMC   2933398 . PMID   19636034.
  28. Manjarrez, Alejandra Manjarrez, Over-the-Counter Antihistamines Could Help Against Cancer , The Scientist, November 24, 2021