At The Moment I Use Cetirizine 10mgs Daily At Night

At the moment I use Cetirizine 10mgs daily at night to reduce congestion at night. As if I don't take it I get extra flem / mucous , wheeze etc both nasal postural drip and in the chest. Then having to use Ventolin inhaler. I never been a asthmatic until recently when I had 3months of chest infection. Took 3 lots of antibiotics and prenisone twice to clear. Still not quiet over it. My question is Cetirizin is there a time frame you use it up or can I use it. Have used it in the last 3 weeks regularily so can I use for another couple of weeks