Singulair and urinalysis

My 3 1/2 year old son has been on Singulair for 4 days now. Needless to say, I am grateful to have stumbled across this website when I googled "asthma medications, nosebleed" after he had the first spontaneous nosebleed of his life, yesterday. Since this had never occurred before, I wondered if his meds could have something to do with it. (He is also on Flovent and Ventolin as he has just suffered his second asthma episode in a month. He has been on both these meds before and I have not witnessed any notable adverse effects with these)
I have also noticed a slight shift in his attitude and willingness to do as he's asked since day 1 of Singulair. This is extremely unusual for my very sweet, cooperative, focused child. He also stated today that he did not love his older brother, whom he adores. He has actually hit me and kicked me on several occasions, which is so unlike my little momma's boy, it had me wondering about the Singulair even before I came across this website.

I am also wondering if anyone knows whether Flovent or Ventolin can cause extremely frequent urination? He is running to the bathroom every few minutes at times. (this was happening before starting on Singulair)
His urinalysis shows that he has no bladder infection and sugar is normal. Help!!!