His doctor said children's zyrtec is cleared for 6months and older. But ask your pediatrician. He's been taking zyrtec for about a year now and it helps so much. If I so much as miss one dose (even just giving it an hour later) he's all puffy and stuffy.
You can give her children’s Claritin or children’s Zyrtec. Call your pediatrician office and ask them for a dose chart. I give my 12 month old Zyrtec, he’s 20 lbs and gets 2ml