To give my 4 yr old antihistamines for age 6 and over?

[Hullabaloo9]

My son has terrible hay-fever. It affects his breathing badly and he coughs till he is sick (I am trying to get him assessed by the dr but that is proving ridiculously difficult/impossible at the moment).

He usually has Piriton morning and night but his bottle has run out and the only other antihistamine I have is a bottle of Piriteze which is for age 6 and up.

He is 5 in June and very tall for his age at 123cm.

Can I give him the Piriteze tonight?

Give him a lower dose or dilute I'm sure it'll be fine.

I think it is based on body weight, I'd give it diluted if he is suffering.

Agree with pp, I’d give a slightly lower dose.

Brilliant, thank you. If its body weight im sure it will be fine. He's easily 6 yr old size.

You know it's a different drug to piriton, yes?
Piriton is chlorphenamine maleate and piritese is cetirizine hydrochloride.
But both are used for hayfever, and the piritese is ok fir 2+ - according to NHS