"Antihistamines act to prevent the release of histamine, prostaglandins and leukotrines and have been shown to prevent the migration of inflammatory mediators. The actions of chlorphenmine include inhibition of histamine on smooth muscle, cappillary permeability and hence reduction of oedma and wheal in hypersneitivity reactions such as allergy and anaphylaxis."

...this is off the Piriton product datasheet. The official, printed, online, MHRA-agreed information sheet with the LICENCED uses of these medications. What is this, how many typoes can we cram into one paragraph? O_o