Field of Science

Agonists and Allergies

My mast cells are leaking histamine and I am miserable. Histamine is a small molecule that binds to receptors in a wide variety of tissues including, alas, the respiratory system. It happens to increase vascular permeability - in other words, it's causing fluids to leak through my capillilary walls and into my nose. Sigh.

I'm fighting back by taking a histamine antagonist, diphenhydramine to be precise. Antagonists bind to a receptor and block its response, in this case inhibiting the H1 histamine receptors in the respiratory tract (H2 receptors cluster in the gastrointestinal tract - and so H2 antagonist, like Zantac, are used to treat heartburn). Agonists are molecules that bind to a receptor and cause a response. Why would you want to take something that binds to a histamine receptor and provoke a response? Turns out there are a couple of drugs that are histamine agonists, including one for Meniere's disease and another that may have theraputic potential for diabetes.

What does the term amine have to do with camel dung? Read about it here.


  1. Eeeew, why are you using that old outdated drug?
    I used to take it but the side-effects were awful. I'd say it's time to upgrade to loratadine, it's much gentler on the CNS.

  2. Alas, loratadine did not seem to work as well for me -- I tried it first.


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