Claritin d extented use safe?

Patient: Have always fought with allergies, stuffy nose, headaches, earaches, post nasal drip etc. I have been using Claritin D 24 hrs for years now and it’s the only thing I’ve been able to take that actually works and works well. The problem is, every time i try to stop taking them, within a week or two I get sick. So the cycle starts right back up and I have to get back on Claritin again. My question; is it safe for me to just keep taking the claritin as a preventative for extended periods of time? I don’t experience any negative side affects, and it works. I feel great when taking it. I’ve tried other meds including the claritin without the pseudophederine and this is the only thing that works. Also, I am a 40 yr old very in shape and active male if that makes any difference. Thank you.