Casein has been documented to break down in the stomach to produce the peptide casomorphin (above stated that "Human digestion may break down casomorphins into inactive dipeptides by the enzyme dipeptidyl peptidase-4"), an opioid that acts as a histamine releaser.
The anti-histamine Allegra was created by Dr. Raymond Woosley, former chairman of the Department of Pharmacology.
An H3-receptor antagonist is a classification of drugs used to block the action of histamine at the Histamine agonist
Betahistine is a weak Histamine1 agonist but a very strong Histamine3 antagonist that is used to treat vertigo.
Histidine decarboxylase (HDC) is the enzyme that catalyzes the reaction which produces histamine from histidine.
Famotidine, a histamine H2-receptor antagonist that inhibits stomach acid production