Does Using Montek-LC For Prolonged Periods Have Any Side Effects?

Hi, may I answer your health queries right now ? Please type your query here...I am 73 years old male and was advised my doctor to take montek lc one at night to tackle my allergic rhinitis and asthma chronic problem.I am taking it since December 2009,more than a year now without problem.Can there be any other side effect due to long term use?Please advise.