Hi. Welcome To Healthcaremagic The most common side effects with SINGULAIR include: upper respiratory infection fever headache sore throat cough stomach pain diarrhea earache or ear infection flu runny nose sinus infection Other side effects with SINGULAIR include: increased bleeding tendency allergic reactions [including swelling of the face, lips, tongue, and/or throat (which may cause trouble breathing or swallowing), hives and itching] dizziness, drowsiness, pins and needles/numbness, seizures (convulsions or fits) palpitations nose bleed, stuffy nose diarrhea, heartburn, indigestion, inflammation of the pancreas, nausea, stomach or intestinal upset, vomiting hepatitis bruising, rash joint pain, muscle aches and muscle cramps tiredness, swelling Cough and colds are common in children.Motus can be given for few months. You can also use cetrizine, allegra, etc. Regards, Dr. Jagdish