H1 Antagonist - Pharmacology

Pharmacology

In type I hypersensitivity allergic reactions, an allergen (a type of antigen) interacts with and cross-links surface IgE antibodies on mast cells and basophils. Once the mast cell-antibody-antigen complex is formed, a complex series of events that eventually leads to cell degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil occurs. Once released, histamine can react with local or widespread tissues through histamine receptors.

Histamine, acting on H1-receptors, produces pruritus, vasodilation, hypotension, flushing, headache, tachycardia, bronchoconstriction, increase in vascular permeability, potentiation of pain, and more.

While H1-antihistamines help against these effects, they work only if taken before contact with the allergen. In severe allergies, such as anaphylaxis or angioedema, these effects may be so severe as to be life-threatening. Additional administration of epinephrine, often in the form of an autoinjector (Epi-pen), is required by people with such hypersensitivities.

Read more about this topic:  H1 Antagonist

Other articles related to "pharmacology":

Cosmetic Pharmacology
... Opponents of cosmetic pharmacology believe that such drug usage is unethical and that the concept of cosmetic pharmacology is a manifestation of naive consumerism ...
Pharmacoepidemiology
... To accomplish this study, pharmacoepidemiology borrows from both pharmacology and epidemiology ... is the bridge between both pharmacology and epidemiology ... Pharmacology is the study of the effect of drugs and clinical pharmacology is the study of effect of drugs on clinical humans ...
British Journal Of Clinical Pharmacology
... The British Journal of Clinical Pharmacology is a peer-reviewed medical journal published on behalf of the British Pharmacological Society by Wiley-Blackwell ... Society by Wiley-Blackwell is the British Journal of Pharmacology ... of 3.578, ranking it 53rd out of 260 journals in the category Pharmacology Pharmacy ...
Pharmacology - Education
... The study of pharmacology is offered in many universities worldwide in programs that differ from pharmacy programs ... Students of pharmacology are trained as biomedical researchers, studying the effects of substances in order to better understand the mechanisms which might lead to new drug ... In addition, students of pharmacology must have detailed working knowledge of those areas in which biological or chemical therapeutics play a role ...