My 4 year old has post nasal drip, causing her to constantly clear her throat. will clartin or zrytec help? which works better? thanks

Post nasal drip: Humidification (humidifier/vaporizer) plus saline nasal spray will help flush allergens out. Different antihistamines work better for different people. Claritin less likely to cause drowsiness but not approved for under 6 y/o; zyrtec ok 4 her age; use proper dose. Another choice is benadryl(but drowsiness much more likely). If not better, see peds.

Consider reflux: Gastric reflux commonly causes a sense of post nasal drip so that throat clear is common. Consider antacid trial. If antihistamines don't work consider nasal steroid sprays.