There are sooo many drugs that are given for other reasons (allergies, pain meds, anti-nausea, etc) that are cough
suppressants as well. i/e hydrocodone
(one brand name is lortab) is also a cough
suppressant, phenergan (anti nausea) is also a cough suppressant...Of course the examples I gave are rx and not recommended for children. benadryl would be fine, just give the recommended dosage for their age/weight. It would probably be 1/2 tsp for the 2 year old, & 3/4 tsp for the 3 year old.