Antihistamine syrup produced by Stafford-Miller. Promises "fast relief from skin allergies and hayfever", and it actually works quite well.
Tastes wonderful; very sweet and minty.
Its active ingredient is chlorapheniramine maleate, with 2mg for every 5 ml spoonful. It also contains (largest ingredient downwards): sugar, glycerol, alcohol, 'Tingle Flavour' (apparently), peppermint oil, water, preservatives and esters of para-hydroxybenzoic acid.
As with all antihistamines, taking Piriton with MAOI antidepressants is a Bad Idea of the toxic and fatal variety.