Suppression of wheal and flare in histamine test by the main H1 antihistamines commercialized in Brazil

H1-antihistamines suppress wheal-and-flare reaction and skin blood perfusion measured by Laser Dopppler flowmetry: randomized, double-blind, placebo-controlled, crossover design study The aim of our study was to compare the influence of pre-treatment with H1-antihistamines (levocetirizine, desloratadine, clemastine, quifenadine, and sequifenadine) and a placebo on the histamine-induced weal and flare reaction, increase of skin blood perfusion and sedation. Thirty healthy volunteers were enrolled in the study. The study design was a prospective, randomised, double-blind, placebo-controlled, crossover, balanced clinical trial. Volunteers in randomised and double-blind order were treated with oral levocetirizine 5 mg, desloratadine 5 mg, clemastine 1 mg, quifenadine 50 mg, sequifenadine 50 mg or a placebo. Two hours after intake of medication, the histamine skin prick test was performed and skin blood perfusion was registered with further evaluation of sedative effect. We conclude that levocetirizine induced a significant and pronounced decrease of weal and flare reaction and skin blood perfusion compared to the placebo and the other H1-antihistamines. The effect of quifenadine and sequifenadine on weal reaction area was similar to desloratadine and clemastine. Regarding the sedative effect, we can conclude that second generation antihistamines appear to be not non-sedative but the least impairing, and the first generation antihistamines appear to be the most impairing on central nervous system function. There is a necessity to consider the sedating potential of antihistamines, along with other factors such as efficacy, when prescribing antihistamines to patients.

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Investigation of the effect of loratadine and calcium ions on oxidoreductase activity of catalase enzyme

Current Enzyme Inhibition ◽

10.2174/1573408016999200817173859 ◽

2020 ◽

Vol 16 ◽

Author(s):

Edhem Hasković ◽

Safija Herenda ◽

Zehra Halilović ◽

Snežana Unčanin ◽

Denis Hasković ◽

...

Keyword(s):

Calcium Ions ◽

Enzyme Reaction ◽

Analytical Techniques ◽

Competitive Inhibitor ◽

Cellular Functions ◽

Oxidoreductase Activity ◽

H1 Antihistamines ◽

Activity Of Enzymes ◽

The Given

Background: The Spectrophotometric method is one of the most suitable analytical techniques for testing the activity of enzymes under the influence of various factors. Methods: The effect of H1-antihistamines of loratadine and calcium ions on enzyme catalase under in vitro conditions was investigated in this paper. Results and Discussion: It has been shown that loratadine isa partial inhibitor of catalase, but this effect is diminished in the presence of calcium ions. Calcium as well as other cations are important for many biological and cellular functions. The kidneys play a central role in the homeostasis of these ions. The activity of the catalase enzyme under the given conditions, the type of inhibition,and the kinetic parameters of the enzyme reaction were determined. Conclusion: We concluded that loratadine is a partially competitive inhibitor.

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Efficacy and Safety of H1-Antihistamines: An Update

Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry ◽

10.2174/1871523011202030230 ◽

2012 ◽

Vol 11 (3) ◽

pp. 230-237 ◽

Cited By ~ 26

Author(s):

Fusun Kalpaklioglu ◽

Ayse Baccioglu

Keyword(s):

Efficacy And Safety ◽

H1 Antihistamines

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Intractable Itch in Atopic Dermatitis: Causes and Treatments

Biomedicines ◽

10.3390/biomedicines9030229 ◽

2021 ◽

Vol 9 (3) ◽

pp. 229

Author(s):

Yoshie Umehara ◽

Chanisa Kiatsurayanon ◽

Juan Valentin Trujillo-Paez ◽

Panjit Chieosilapatham ◽

Ge Peng ◽

...

Keyword(s):

Quality Of Life ◽

Atopic Dermatitis ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Clinical Problem ◽

Transient Receptor Potential Channels ◽

Protease Activated Receptors ◽

H1 Antihistamines ◽

Potential Channels

Itch or pruritus is the hallmark of atopic dermatitis and is defined as an unpleasant sensation that evokes the desire to scratch. It is also believed that itch is a signal of danger from various environmental factors or physiological abnormalities. Because histamine is a well-known substance inducing itch, H1-antihistamines are the most frequently used drugs to treat pruritus. However, H1-antihistamines are not fully effective against intractable itch in patients with atopic dermatitis. Given that intractable itch is a clinical problem that markedly decreases quality of life, its treatment in atopic dermatitis is of high importance. Histamine-independent itch may be elicited by various pruritogens, including proteases, cytokines, neuropeptides, lipids, and opioids, and their cognate receptors, such as protease-activated receptors, cytokine receptors, Mas-related G protein-coupled receptors, opioid receptors, and transient receptor potential channels. In addition, cutaneous hyperinnervation is partly involved in itch sensitization in the periphery. It is believed that dry skin is a key feature of intractable itch in atopic dermatitis. Treatment of the underlying conditions that cause itch is necessary to improve the quality of life of patients with atopic dermatitis. This review describes current insights into the pathophysiology of itch and its treatment in atopic dermatitis.

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The effect of ranitidine, alone and in combination with clemastine, on allergen-induced cutaneous wheal-and-flare reactions in human skin

Journal of Allergy and Clinical Immunology ◽

10.1016/0091-6749(85)90761-4 ◽

1985 ◽

Vol 76 (6) ◽

pp. 864-869 ◽

Cited By ~ 9

Author(s):

R THOMAS ◽

P BROWNE ◽

J KIRBY

Keyword(s):

Human Skin ◽

Wheal And Flare

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Histamine Intolerance—The More We Know the Less We Know. A Review

Nutrients ◽

10.3390/nu13072228 ◽

2021 ◽

Vol 13 (7) ◽

pp. 2228

Author(s):

Martin Hrubisko ◽

Radoslav Danis ◽

Martin Huorka ◽

Martin Wawruch

Keyword(s):

Gold Standard ◽

Multidisciplinary Approach ◽

Adverse Reactions ◽

Immunological Response ◽

Food Intolerance ◽

Therapeutic Approaches ◽

Complex Time ◽

Histamine Intolerance ◽

The World ◽

H1 Antihistamines

The intake of food may be an initiator of adverse reactions. Food intolerance is an abnormal non-immunological response of the organism to the ingestion of food or its components in a dosage normally tolerated. Despite the fact that food intolerance is spread throughout the world, its diagnosing is still difficult. Histamine intolerance (HIT) is the term for that type of food intolerance which includes a set of undesirable reactions as a result of accumulated or ingested histamine. Manifestations may be caused by various pathophysiological mechanisms or a combination of them. The problem with a “diagnosis” of HIT is precisely the inconstancy and variety of the manifestations in the same individual following similar stimuli. The diagnosing of HIT therefore requires a complex time-demanding multidisciplinary approach, including the systematic elimination of disorders with a similar manifestation of symptoms. Among therapeutic approaches, the gold standard is a low-histamine diet. A good response to such a diet is considered to be confirmation of HIT. Alongside the dietary measures, DAO supplementation supporting the degradation of ingested histamine may be considered as subsidiary treatment for individuals with intestinal DAO deficiency. If antihistamines are indicated, the treatment should be conscious and time-limited, while 2nd or 3rd generation of H1 antihistamines should take precedence.

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