We tried a ton of things and combinations for our son's asthma and environmental allergies and eczema. We had a failed attempt at S.ingulair at one point, and then, as he got older, his sensitivities to medications lessened, and he now tolerates it well. We also tried various inhalers, and none of them were effective, and all of them caused behavioral issues.
In terms of antihistamines, he was on all of the major OTC meds, and finally ended up on X.yzal. The combination of the two meds has made a world of difference for him.
The real key though, was finally putting the pieces together and finding soap and lotion that don't contain his allergens.
so, I dont have great advice about the monitoring, except to say that in our experience, we were able to determine his behavioral reactions well based on our and his daycare providers observations. I spent a lot of time late at night listening to his lungs for wheezing, too.
