yeah it should be since its a human drug. should be a 4mg tablet may also be known as chlorphenaimine ( piriton is the trade name). just stick to the same dose your vet prescribed.
yes it's exactly the same. My dog ets Piriton too but I stick to getting them from the vets as I get 30 for under �2 whereas if you went to the chemist you'd only get around 7 for more than �2.
But like you I asked the vet to find out if they were the same in case I should one day run out and the vets are closed or not near by