Singulair Side Effects: I am 33 years old and have been taking Singulair for 4 years. I http://www.medications.com/effect/view/28575 I am 33 years old and have been taking Singulair for 4 years. I have severe seasonal allergies and Singulair was the only RX that would work without knocking me out. I was prescribed to take one a day/everyday. These past two years I have suffered from dep Please respond to my reply. I ca help you. Fri, 28 Mar 2008 15:19:38 -0400 http://www.medications.com/effect/view/28575?item=6045 Please respond to my reply. I ca help you. http://www.medications.com/effect/view/28575?item=6045