What Are The Side Effects Of L Montus 10 Mg?

SIR, I am 17years old gal.. I sufferd frm allergic cough for d past 1 month.. now it has reducd a lot...bt 2-3% of it has not gone yet also..my doctr has prescribed me to take L MONTUS 10MG...for 2 months.. cn u let me know is der any side effects of idz medicine? as i am constantly gettin headache..n also d feelin of nausea..!! plz guide me..!