Singulair Side Effects: Researchers have been doing studies for many years regarding tryi http://www.medications.com/effect/view/38627 Researchers have been doing studies for many years regarding trying to determine the role of genetic factors in patients response to Singulair (Montelukast). This study from Spain identified the following gene variations hypothesize to be related to leuk Singulair most reported side effects and reactions by year Year Tue, 03 Feb 2009 18:23:08 -0500 http://www.medications.com/effect/view/38627?item=16714 Singulair most reported side effects and reactions by year Year Description Frequency 2004 ALLERGIC GRANULOMATOUS ANGIITIS 66 ABDOMINAL PAIN 7 ALANINE AMINOTRANSFERASE INCREASED 6 ASTHMA 6 CONVULSION 6 2005 ALLERGIC GRANULOMATOUS ANGIITIS http://www.medications.com/effect/view/38627?item=16714 flindy, You comment was made through keen observation. I tend Tue, 03 Feb 2009 23:00:07 -0500 http://www.medications.com/effect/view/38627?item=16725 flindy, You comment was made through keen observation. I tend to agree with you that vasculitis is possibly connected to Singulair adverse side effects. My opinion is that Singulair and nitric oxide is the key issue. Excessive production of nitri http://www.medications.com/effect/view/38627?item=16725