Oh my gosh, I am just shocked after reading these posts. I am ta...

I have always believe that doctors regard Singulair in the same category as an anti-histamine. The fact that Singulair inhibits histamine is not a direct process. Merck has misled them and confused them.

Adverse Reactions
(As reported in adults)
>10%: Central nervous system: Headache (18%)

1% to 10%:

Central nervous system: Dizziness (2%), fatigue (2%), fever (2%)

Dermatologic: Rash (2%)

Gastrointestinal: Dyspepsia (2%), dental pain (2%), gastroenteritis (2%), abdominal pain (3%)

Neuromuscular & skeletal: Weakness (2%)

Respiratory: Cough (3%), nasal congestion (2%), upper respiratory infection (2%)

Miscellaneous: Flu-like symptoms (4%), trauma (1%)

Postmarketing and/or case reports: Agitation, anaphylaxis, angioedema, arthralgia, bleeding tendency, bruising, cholestasis (rare), diarrhea, dream abnormalities, drowsiness, edema, eosinophilia, hallucinations, hepatic eosinophilic infiltration (rare), hepatitis, hypoesthesia, insomnia, irritability, muscle cramps, myalgia, nausea, palpitation, pancreatitis, paresthesia, pruritus, restlessness, seizure, urticaria, vasculitis, vomiting

I just want to respond to your statement "This medicine should be outlawed." While I do agree that research and public awareness of the possible side-effects should be done, there are some of us that take Singulair without negative side-effects. I have been taking it for eight years, since I was 16 and have never had any of these side-effects. There was a couple of months that I did not take it because of financial issues, and the only thing that I noticed was that my asthma and allergies were horribly worse. These were both relieved dramatically when I resumed taking it. Without it, I would spend my days in an allergy/anti-histamine fog not being able to breathe while still taking my inhaler 4+ times a day and several during the night. That is just the beauty and flawed nature of medicines: they work perfectly for some but for others the negative side effects outweigh the benefits. I am sorry for your son's and family's hard times with it.

Thanks for your insights. My son has many of the same symptoms that your son had, including hyperactivity. His teacher also felt he had ADD. Yet when I look back on when his misbehavior started, (irritability, constantly moving, unable to sleep, inability to focus) it was when he was put on Zyrtec and Singulair.
I'm calling my allergist immediately. I knew I wasn't crazy!!