Singulair Side Effects: im having cough and then wheezing for a couple of minutes. My doc http://www.medications.com/effect/view/41675 im having cough and then wheezing for a couple of minutes. My doctor thinks its common allergies, but I wasn't having my usual allergy attacks. She put me on Singular and It's been 3wks now and I've been feeling worse than ever. Cough and wheezing are possible side effects of Singulair. Go to Fri, 22 May 2009 10:55:23 -0400 http://www.medications.com/effect/view/41675?item=20021 Cough and wheezing are possible side effects of Singulair. Go to http://www.parentsforsafety.org/17601/10794.html for more information. http://www.medications.com/effect/view/41675?item=20021