I started taking this medication in 1996 for allergies and itchiness. I have tried many times to stop taking it and after 3 days develop severe itching and burning particularly on my hands, feet and scalp. I thought it was my allergies acting up and started taking it again. I have since learned that this is a form of withdrawal from this medication. I am very upset that I ever started taking it, as I don't know how I am going to quit. It is really too painful to try and stop. I am not the only one who has experience this reaction. Now that is over the counter it scares me. Beware!! Published: May 07, 2008 ::

My teenage son suffers from both seasonal and non-seasonal allergies. After years of using Claritin, his doctor suggested Zyrtec because the Claritin was not as effective any more. Within three weeks of beginning this drug, my son went from a happy, curious teenage athlete, who made good grades to being depressed, with no interest in anything, even his favorite sport. Getting him out of bed to go to school became an unprecedented battle daily. He became easily aggitated, but his overall outlook on everything was total hopelessness. He had great difficulty going to sleep at night, but when he did fall asleep, was difficult to awaken, and was tired and rundown the rest of the day. If given the chance, he would sleep 12 or more hours straight, but then would still be exhausted with little energy. I am throwing out the Zyrtec, and reporting these symptoms to his doctor. I recommend everyone else report similar side effects to their doctors as well. Thank yOU to all who posted and shared their difficulties with this drug, as well as WebMD for giving us a forum. Without all of you, I would have kept my wonderful son on this awful medication, watching him become more and more depressed, and losing interest in life. I shudder to think of the possibilities that may have ensued! My advice: DO NOT TAKE THIS MEDICATION!! Published: April 14, 2008 ::

My 3 year old daughter took this medicine and her whole personality changed. She became very agressive and angry which was a drastic change from her normal friendly dispostion. At first I thought it was just a new phase of being a 3 year old. But I noticed taking her off of it for a few days that she would return to her normal happy self. When I think of the number of times I punished her for being contrary when the cause was a reaction to the medication - shame on mommy! I urge all parents to be aware that this medicine can alter your child's mood/personality. Published: September 28, 2007 ::

This medicine had serious adverse longterm side affects on me. They included first and foremost a lack of an ability to concentrate. They also included tense, sore muscles - especially in the neck - fequent headaches, chronic fatigue, mild depression, general irritability, and minor weight gain. After taking it for months I didn't take it on a Friday. By Monday I felt 10 years younger. Within a week I felt 15 years younger. The symptoms developed slowly over several months, so I didn't realize them till the weekend I experimented with not taking it. If you've been taking this medicine for a while and have experienced any of these symptoms you might want to try getting of it for a week and seeing how you feel. As for me, I'll never take it again. Published: September 26, 2007 ::

I took Zytrec for 7 years. It worked great! No hives and no hay fever. After about 4 or 5 years I started having some very vivid and terrifying dreams and nightmares; most of these involved killing people (about 2 or 3 times a night). I was kind of stuck because none of the other medicines had done anything for my hives (Claritin and Allegra). I finally had to stop taking Zyrtec because in one dream where I was in a fight, I actually swung my arm and punched my wife in the nose. Afterwards I went online to search for these type of side effects to the drugs and read that some people were saying that Zyrtec contributed to or created nightmares and even made your allergies worse! They said that the drug made you very dependent on it. Finally after two years on the drug, I went to the doctor and changed to Claritin. Now I only take 1 Claritin once a week versus 1 Zyrtec every day and there are no nightmares! Zyrtec worked great at doing what it was supposed to do, but the side effects were not worth the cause. I also concur that Zyrtec makes your allergies worse. I took it mainly for my hives. After 26 hours of taking my medicine, I would get hives. Like clockwork. How is it now that I am able to go a week with no bad outbreaks and no nightmares? Coincidence? Be careful with Zytrec, I'm worried because it is now an over-the-counter drug. Published: April 25, 2008 ::

I changed to Zyrtec because it was cheaper than Allegra and my insurance does not cover non-sedating antihistimines. While on Zyrtec for 25 days I gained 10 pounds (made no adjustment to my diet so I don't know where that weight came from), was very drowsy, was easily agitated, and saw the top number in my blood pressure go from 108 to 138! And, I still ended up with sinus headaches from my allergic triggers (Spring!). After being off Zyrtec for a week, I'm happier, not sleepy, loosing the weight (still not on a diet!), and returning to Allegra. Published: March 31, 2008 ::