Zyrtec and exacerbation

I am a 37 year old female ~185lbs already under treatment for clinical depression with two medications. I used to take Alavert (loratidine) for seasonal allergies but found it had "stopped working" well for me. Since Zyrtec (certirizine) went over-the-counter, I decided to try it.

I took it sporadically at 10mg daily for a period of 2-3 weeks, and then, during a particularly bad allergic exacerbation, began to take it consistently at 10mg daily. My depression, which was previous well-controlled on medication, worsened to the point of severity. Extreme despair, emotional detachment, and loss of interest in pleasurable activities--well, in ANY activity beyond sleep.

I am a pharmacist, and on a whim, I decided to do some research into interactions with my other medications, and found several anecdotal reports of depression onset and worsening in Zyrtec users. This particular side effect of Zyrtec was unknown to me, nor have I received any educational materials or reports in my trade literature listing depression as a possible adverse effect.

I have discontinued the medication in both myself and my three year old daughter (5mg daily). I can already see a difference in her disposition, and I am starting to crawl out of my pit of gloom. I'm using Alavert again, as I never had one issue with it, and I'm supplementing with Benadryl (diphenhydramine) at night as needed for exacerbations.