Asthma diagnosis symptoms and conditions

when my son (now five) first started treatment for allergies at almost 3, he went on zyrtec and singulair. he was moody, grumy, and needy. i just assumed he was 3. after about 10 months the allergist switched him to pcm chewables with his singulair and he turned evil. for example, he wasn't quite 4 and attacked me one night because he didn't want a bath. it took several minutes to pry his hands of of my neck. it scared me to death. since he was already on singulair i assumed it was the pcm and finally found a pharmacist who said that it "might" can have those side effects. the allergist wouldn't accept that it could do that and wouldn't change his prescription. finally went to new allergist who changed him back to zyrtec but wanted to stay on singulair due to new asthma diagnosis. his behavior got better, but still very moody - many ppl said "spoil" because of huge meltdowns over nothing. he is now 5 and has been on allergy shots for a year. about 6 months ago the doctor said could take him off zyrtec but keep on singulair. i thought yay! mood will get better. it didn't. he was still getting notes from kindergarten teacher for talking too much, fighting, moodiness, meltdowns, etc. we took him off singulair to see how asthma would do since allergies doing better. he started getting greenlights! we still have some meltdowns and moodiness. but, it is slowly getting better. i wonder how long it takes to clear out of their system?
in the last six months we have periodilly put him back on zyrtec and singulair when allergies acting up. his teacher tends to send home notes that week asking if he is on medicine. it never occurred to me that it could be the singulair! what scares me is that 3 weeks ago he said he wanted to get a knife and cut his head off so he could "go to Jesus". i talked to him and finally decided he was just talking, don't think he truly meant it. but now, i look back and realize he was on singulair at the time!
the scary thing is that my one-year old is also on it for asthma. i got put on it recently for chronic sinus problems and my husband has been on it for years! i think I will not be giving it to any one until we talk to the doctor!

as a side note i have a friend with a 22 mo old that drs have tried to put on singulair off and on since she was 12 mo or so. every time it makes her unable to sleep. mother agreed to try it again recently because child's asthma was so bad and they ended up at the ER because the baby couldn't quit crying!

my daughter has been on Singulair for 4 days now. She is 2 years old and has bad food allergies that cause very bad eczema. She also has been diagnosed with the start of asthma. After going to an allergist, we were told that she should try Singulair and Allegra for a couple of months to treat her seasonal allergies which have been causing coughing at night and skin break-outs, etc. A day or so after she took the medicine ( Singulair chewable tablets- I haven't started the Allegra yet, it seemed like too much for her to be on ) she has been having very loose stools, and quite a few throughout the day. Also she has hive- like bumps on her back. I stopped giving it to her the day before yesterday because the medicine was the only new thing she had been introduced too. The stools seemed to slow down and the hives seemed to be going away, but she was coughing bad last night, so I gave it to her again thinking maybe all she had was a stomach bug. But this morning we made countless potty stops and her back is bumpy again. Does anyone else have this problem?