Objective symptoms and conditions

Hi everyone
My little boy who is nearly two was put on Singulair as a preventative.
I did check on forums when we started using Singulair and I was concerned that there has been descriptions of negative affects. Always trying to be objective I rationalised that the people in this forum are a small part of the greater Singulair population and as a result there was a low risk of negative affects on my little boy.
I have to say I think I was wrong. As soon as he was using Singulair, he had restless nights of sleep. Every night he would cry off and on until 2am and I guess he was so tired he slept. During the day he was very short tempered and became upset very easily. We put this down to tiredness. After 10 days of the lack of sleep for parents and little one, we told our doctor.
He advised to take him off Singulair for 5 days and make observations and then put him back on. Last night, his first night off Singulair was bliss. Not a sound. He had a great sleep. As I type he is now having another great sleep.
Let us see what happens after 3 more days and after putting him back on Singulair.
It would seem that if we are correct and that Singulair is a cause of an issue for my child, am I a quasi beta testing laboratory for a drug?
We are from Australia.
Thank you for reading.

I am finally writing after reading these posts since the end of April. That is when I took my 11 year old son off singulair, in an act of desperation. He has been on singulair on and off for about five years for seasonal allergies. He started again in mid-March so it could get into his system, before the allergies started. Immediately thereafter his behavior changed. He was arguing on a daily basis. He would hit, kick or trip me when he was angry. He was starting to destroy things in anger. He seemed to be fueled by anger. It was affecting the whole family. He was starting fights with his younger brother, my husband's heart was palpitating and I was crying every day. I heard about Singulair side effects and looked it up. I saw that it caused behavioral changes and out of desperation, took him off, not knowing what to expect. We had three days of total peace, then on the fourth day another outburst. Then my son told me he had taken a singulair the night before. That was it. I threw every pill in the garbage. He no longers acts like that. It's been almost two months so I am convinced it was the Singulair. By the way, he always complained of headaches, stomach aches and would scream in his sleep. Who knew - it was the singulair all along.