I was taking Zyrtec for the past 8 years and I am also on Antidepressants ( Effexor) and on Singulair. I had to stop taking the zyrtec 72 hrs prior to being re-tested for my allergies. I had done this once before and knew that the withdrawals were pretty intense, with itching so bad it made me want to go to the hospital. This time I looked up Zyrtec withdrawals and was shocked at the information I discovered. I stopped cold turkey and I am miserable with the itchiness. I also discovered that I don't get so short of breath( I run ) during my exercise. never going back on that stuff again. I still have allergies and get shots every 3 weeks but haven't had any problems not taking the zyrtec in relation to my allergies.