Zyrtec oral for under 5 years old kid

>>Tell me your experience.

Paul, I think it's because a similar question has been asked that this site comes up high in the list of those that may supply an appropriate answer. Yes this is an IT site, but realise that IT is involved in many disciplines. Someone who came here looking for advice on how to improve his medical database might be a competent doctor in 'real life'.  Some one who comes here asking a medical question might have exactly the answer you will need next week for an unexpected event at your home.
I don't think your comment helped answer the question. You would be better to answer as best you know how stating that you have no medical experience, or better not to comment at all so other experts with experience in this field can give a proper answer. Now this question has two unhelpful comments ( ypurs and mine) and won't be opened by many who could perhaps help.

Do you want to know about the branded drug or cetirizine generically? - Specifically in paediatric medicine?  General use or specifically for management of allergy or vertigo or as a sedative agent?

I am doing a research for the subject medicine at what level? For your own interest or are you being employed to do this? Is this an under 5 year old  relative you're talking about?

@MASQ

Your guess is correct.

It is just my personal interest as the drug concerned is a non-prescribed drug and I want to know more about it for any side effect for kid (my daughter) as I might not have the time to dig the info deep enough for a more thorough understanding.

I know that doctor advice might be better but it is likely some members have medical background whom might give me some insights.

Why is it being used in your case?

Wheeze and fever

Thanks for your advice.