Government reports symptoms and conditions

hi, im not sure what to do. my 3 1/2 year old daughter was today given the prescription for singulair. i voiced my concerns to the doctor after my friend telling me its no good due to the side effects.she said that there are risks and side effects with any drug you take but for some reason i don't feel right about this. don't doctors know better than this. anyway Would like to know if all the people who take singulair suffer some sort of side affects or is it minimal? or going by this side it looks like its probably best not to give it to her at all.