Everyone knows that kids can react to drugs differently; it's why you test the Benadryl before the flight to see if your kid's one of goes-to-sleep kind or the bounces-off-the-wall kind.
As we found out last night at 01:55, there are apparently two kinds of antihistamines: the kind that helps the kid sleep through the night, and the kind that helps the kid sleep for five hours and fifty five minutes, then suddenly flicks on on a flourescent light in her brain.
I'm not a doctor, but I can see two differences here: active ingredient and brand:
Robitussin Pediatric Cough & Cold has chlorpheniramine maleate, while the CVS Children's Cold & Allergy Elixir [nice retro w/ the 'elixir,' but it was the only thing on the shelf at one point] has brompheniramine maleate. The writeups sound indistinguishable from each other.
So it must be brand: store brands apparently offend her delicate sensibilities.
Related: I assume everyone already knows and uses The Medicine Cabinet at AskDrSears.com to check dosages and active ingredients for all the major infant and pediatric medicines, right? You might say we're quite attached to it.