My 2-and-a-half year old son has been taking this horrible drug for 6 weeks now. Since then he has been unhappy, negative, aggressive, and defiant, and this has been a change from his normal "terrible two" behavior. He has had trouble falling asleep and has awakened with horrible nightmares. I would never recommend this medicine to anyone, especially after reading other people's testimonies.

my son is moody and withdrawn...I used to have to struggle to get him to come inside, not I have to push him to do anything....is very lethargic and moody...not at all the happy kid he was before taking this medicine.

I was diagnosed with mild asthma one year ago. My doctor started me on an inhaler, but after 6 months of being on that I developed oral thrush. So four months ago he switched me to singulair; I take it every other night. My breathing is fantastic! however, I've put on 5 lbs and notice I'm either irritable or "down" much of the time. I'm going to cut back the dosage to just twice a week to see if my asthma is still controlled AND to see if my mood improves. Otherwise I'm going to stop taking it!

Before taking this drug,my 11yr.old daughter was a very happy child.She became very defiant,cried and was depressed while on Singular.She couldn't handle it and neither could I.Her personality changed completely. As for her Asthma it improved. She was on Singular twice and both times it affected her mood drastically.I will not put her back on this drug.She does better with Benadryl or Claritin.

I have recently been diagnosed with multiple allergies w/asthmatic symtoms.I have been taking Symbicort,Zyrtec and Nasonex.But was still experiencing symptons when excerising.So my doctor added Singulair,the first week it was just vivid dreams and a little weakness.By week three I now have a chronic sore throat, stomach problems,dizziness and more chest tightness. When I called they said my symptons where not typical and said it was a drug well tolerated by many people.I have now stopped taking it, the side affects are not worth it and I did not see a drastic improvement in my symptons

The frustration we have with this medication is that is works beautifully to control our 9 year old son's asthma and allergy symptoms, but changes his entire personality. He develops insomnia on day 2, gets aggressive, anxious, irritated, and very restless during the day. He is normally a happy, easy going, fun boy who gets along with children and adults. This is the second time we have tried this med and once again we are taking him off. The pediatrician did not believe me last year, but this year took my concerns to heart and suggested a short trial period. We tried - we're done. Too bad - it's effective, but not worth the side effects for my son.

My son was on this drug from 2004-2007. During that time he had terrible nightmares and was very sad. He even resorted to self infliciting pain. It was heartbreaking to watch as a mother (he was only 4-7 years old). His teachers noticed terrible mood swings, and he was aggressive. Since he has been off it it is like my child is back! I have also brought him to get his blood tested recently to test his immune system and low and behold -he has a severely depleted immune system which can be a result of the nature of Singulair. I do not think this drug should be marketed to children. Buyer Beware!!!