Drug Ratings for ZYRTECAverage Rating: 2.1 (1508 Ratings)
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Results are sorted by length of time drug was taken from longest to shortest Key to Ratings: 1=LOW (I would not recommend taking this medicine.) Page: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
| RATING | REASON | SIDE EFFECTS FOR ZYRTEC | COMMENTS | SEX | AGE | DURATION/ DOSAGE | DATE ADDED |
  | F M | | | | |||
| 1 | Seasonal allergies | Very bizarre, disturbing dreams which left me exhausted in the morning. | I thought I was going crazy until I read all the other feedback here about people having weird dreams while taking Zyrtec. I've been on Allegra for years, and thought I'd try switching over to Zyrtec for a change of pace - and to see if it worked better. What a mistake! I haven't slept well in the 3+ months I've been on Zyrtec. At first I was attributing the dreams to stress, but when they continued I pinpointed the start of the dreams to about the time I started Zyrtec. So, I've stopped taking it and gone back to Allegra. The weird dreams have stopped and I am getting great sleep. In the past I have also had odd reactions to Claritin and Seldane (anyone remember that stuff?) I would not recommend Zyrtec. | F | 48 | 90 days | 8/7/2009 | 1 | skin rush &spring allergys | Hair loss, weight gain,restless sleep, fatigue and excessive sweating | it did work for my allergy 100% ,today is 3d day after i went off Zyrtec and slept through the night with no interruptions for 1st time since i started take and no more nightsweats and scalp burning ...and allergy is back... It helps with the allergies but the side effects are not worth it. | F | 44 | 70 days 10 mg 1X D | 5/26/2010 History | 4 | Allergies | Tiredness, stomach problems | I've been taking 5mg of Zyrtec for the last couple of months on an "as needed" basis. Before taking Zyrtec I was taking Prevacid for my stomach and thought I was going to be able to go off of the Prevacid soon, as I was doing really well. After starting the Zyrtec my stomach started getting worse and I even had to up the dosage on my Prevacid. Then I developed stomach spasms and had to start taking Levsin. In the past I'd take one or two dosages and things would be back to normal. I have been trying to get my stomach settled down for a week and it's finally more calm. Just tonight when I was thinking about taking a Zyrtec I realized that might be the problem. I found this web site and now I'm sure my stomach issues are from the Zyrtec. I'm going to refrain from taking it and see if my stomach is better. It's most certainly the Zyrtec or Flexeril (5mg) I took from time to time. | F | 47 | 60 days | 6/27/2007 | 3 | Seasonal Allergies | Helped with seasonal allergies but terrible behavior problems as a result. Like so many parents on this site, we never put 2 and 2 together. His teacher pulled me aside today for the 2nd time in 2 weeks to discuss increasing behavior problems and even aggressive behavior. We all think our kids are the best but this one really is a kind natured kid, NEVER before have I been told he is hitting other kids. The teacher felt like he just can’t help himself and was concerned. This site has totally freaked me out. I feel terrible, all the discipline and frustration and it’s a side affect. Increased appetite is something we saw a long time ago. I’m VERY disappointed with the doctors for not having us be on the lookout for this. | Pick your poison, allergy symptoms or behavioral problems. STAY AWAY from this drug, seek alternatives and monitor changes of any kind. | M | 4 | 60 days | 5/10/2007 | 3 | adult onset spring allergies | lethargy, weight gain, rash on my neck, low libido | It has worked better than Claritin for my adult onset spring allergies; I originally tried "natural" remedies, which did nothing to help the sneezing, dripping and achy eyes. However since starting Zyrtec about 2 months ago, I have been needing 9-10 hours of sleep, and still have a hard time getting out of bed. And I have been gaining weight for no apparent reason, about 5 pounds in the last 2 months since I began Zyrtec this year. And a reduction in sex drive the last couple of months. And a mild itchy rash on my neck the last few weeks. As my allergies are seasonal, and they usually subside around now, I stopped Zyrtec 3 days ago and have been having trouble sleeping. Last night I lay awake most of the night. I am very happy to have found this web site and now know that these changes are because of Zyrtec. However, I would take it again next year, maybe try taking less, and taking it at night, or maybe try Claritin again because the constant sneezing and dripping and sore | F | 58 | 60 days | 4/2/2008 | 3 | Seasonal Allergies | weight gain/increased appetite, irritability, mild depression | Zyrtec didn't really work that well for me by itself so my doctor gave me a nasal spray to use with it. That helped, but it still didn't get rid of my symptoms completely. The side effects aren't worth it to me so I'm going off it. | F | 26 | 60 days | 8/1/2006 | 3 | Seasonal Allergies | I took Zyrtec for 2 months and I started experiencing knee pain. I stopped it and the pain was coming down. After a week I had to take it again and the pain increased. Now, I am completely off of it and have no pain at all. | F | 30 | 60 days | 7/10/2009 | 3 | allergies | Switched because OTC Claritan was ineffective at the suggested dosage. Zyrtec seemed effective, but I notice extremely dry mouth--right around the inner area of my lips and a salty taste on and around my lips. | M | 50 | 60 days | 7/3/2008 | 2 | Allergies | My son's behavior changed so dramatically that I was looking into him seeing a child pyschologist. I noticed that his violent and depressive mood swings coincided with his taking the medication. As soon as I took him off of it he was fine! I was so relieved to see that others had the same concern. | M | 7 | 60 days | 10/16/2006 | 2 | Allergies | Like other posters mention, I freaked out. I would yell at my husband and feel no remorse over my actions until the Zyrtec wore off. It was scary. The allergies were at bay, except for the hives. I've learned how to manage my allergies by having my food allergies diagnosed which lessens my seasonal allergy symptoms. Considering the hives were not addressed and I was a psychotic soon to be divorced wife, I'm happy to report that now we're all happy again. And btw Weight Gain, check. | M | 43 | 60 days 1X D | 3/2/2011 | 2 | Toddler Allergies | Took my toddler off of the Children's Zyrtec after a few months because when I used it, it made him tired and cranky. I had to switch to Claritin, which is not as good but less side effects. Doc said that sometimes the sensitivity to Zyrtec seems to be hereditary. I tried adult dosages and even half doses and it still made me too tired. | F | 2 | 60 days 1X D | 6/28/2011 | 2 | hives | Dry mouth, sleepy, lithargic | Zyrtec was prescribed for hives, but on a scale from 1 to 10, it was a 2. | F | 56 | 60 days | 8/16/2004 | 1 | Allergies | Took with Avelox - major hypnotic effect. After Avelox kept taking - kept being very very dizzy - esp. when lying down. Stopped Zyrtec 6 days ago. Good news not dizzy at all anymore! But ITCHY. At first got very itchy palms and skin with red rash. Also eyes very itchy. Taking Benadryl at night now (can't take during day as it makes me too sleepy). Itch better but still there. Hope it goes away. I would not rec this drug to anyone. Side effects too serious. Esp. do not combine with Avelox! | F | 53 | 60 days | 4/19/2007 | 1 | Allergies | While taking Zyrtec, I noticed an inability to focus and organize my thoughts as well as a substantial decrease in attention span. My memory was not as sharp, almost porous, as though I was physically present but without awareness. I became forgetful. I started to procrastinate and found it quite difficult,not to start, but to complete projects, either work or personal. I was quite irritable and easily frustrated - not a fun person to be around. I only took Zyrtec for 2 month. When my seasonal allergy symptoms began to subside, I stopped taking Zyrtec and within a few days, I noticed all of the above symptoms begin to subside. | Although Zyrtec did work in relieving my allergy symptoms, I would never take it again due to the life altering side effects. There are other medications and ways to relieve my allergies than to take this medication. The risk is simply not worth the reward. | M | 44 | 60 days | 11/11/2008 | 1 | Allergies | While it controls my itchy throat and eyes; I am completely exhausted and suffering from weight gain and very achy joints, especially knee and wrist. | F | 50 | 60 days 10 MG 1X D | 3/30/2013 | 1 | for allergies | Used this drug for about 60 days and my general health continued to decline. Although my allergy symptoms are reduced, the side effects are horrible | This is the drug from Hell. The side effects included: Extreem fatique,sore joints and mucles,rise in blood preasure,dizzeness,and overall lethargic feeling. Would never recommend this drug and I can not believe it is an over the counter drug. Over all rating (mean & nasty) | M | 75 | 60 days | 8/7/2008 | 1 | allergic rhinitis | complete 180 in behavior in my normally sweet, good natured 6 year old son! Irritability, inability to concentrate, disobedience, inability to control emotions and what he says. ADHD like symptoms. | My husband and I noticed our son acting wild and a bit disobedient over the summer, but attributed it to running amok at day camp all summer. Our son started 1st grade last week and after being e-mailed by the teacher on a daily basis and getting called for a conference already due to his inability to concentrate, hitting other children and his general irritability and bad behavior, I started doing a little research. Thankfully, I found this site! At first, we thought he might have developed ADHD, but then I started thinking about when his behavior changes started. They coincided with when he started taking Zyrtec! I stopped it today, after confirming with our pediatrician that Zyrtec is the likely culprit. Beware! | M | 6 | 60 days | 9/4/2008 | 1 | Allergies | Severe mood swings, anxiety, sleeping more but never feeling rested,apathy, depression, no desire to do anything, excessive gas (bloating/flatulence), increased appetite, weight gain. | I just began having allergies last year. I was taking Sudafed or Advil Sinus(as needed) but still having sinus/allergy problems. Doctor suggested I try Zyrtec - taken on a daily basis. It worked GREAT for my allergies. Unfortunately, it began to be terrible for my outlook on life. I didn't know what was happening to me. I have stopped taking this medication. Within two days of not taking this stuff, the depression, apathy, gas and increased appetite I was experiencing disappeared. I have energy again. It feels like I have crawled out of a dark pit. I didn't even realize how bad the depression was. It's been five days without this medicine now. I've had mild nausea, dizziness and insomnia but all are fading with each day. The weird thing was the itching that began on day three. I have never had hives or itching before. This is not a symptom of my allergies returning for me...this is a withdrawal. I will NEVER TAKE THIS MEDICINE AGAIN! I'll deal with my allergies some other way. | F | 48 | 60 days | 6/23/2009 | 1 | Allergies | I am unsure if it is Zyrtec but I know for a fact that when my daughter took Zyrtec she began exhibiting violent outbursts, temper tantrums, mood swings, hitting, kicking, screaming at school, towards her friends, and sometimes me. | F | 29 | 60 days | 6/3/2009 | 1 | Migraines Due To Allergies | Extreme Hunger! Weight Gain! Drowsiness! Loss of Consentration! Constipation! | I have been taking Zyrtec for about two months now and I have noticed in these two months I have gained 12lbs! I am completely exhausted. I have a very hard time waking up. I just noticed in the last couple of weeks the constipation. It seems like I can't concentrate on anything. I hope after this stuff gets out of my system that I am back to normal. I will have to go back to Singulair or find something else. | F | 40 | 60 days | 5/20/2009 | 3 | allergies | feeling irritable. Not much energy. noticed a weight gain after just over a month. Watching what I am eating and walking several times a week for several miles has not helped. My feet and hands are swelling at times as if retaining water. Allergy problems have been better but I didnt have any of these side effects with Allegra D. | After finding this site and that many others have had similar problems and horrible withdraw issues I am off it! | F | 40 | 55 days | 5/1/2007 | 4 | Allergies and Asthma | None that I have noticed, although I do take it just before I go to bed, so I'm really unable to tell if it may cause any drowsiness. | I have moderate allergies year round, but I am severely allergic to cats. I have recently moved into a house with three cats. For awhile I was taking other allergy pills that were working okay,but I had to take them more frequently, and I was still suffering a lot of symptoms. When I began to take Zyrtec 24 hour, Nearly every one of my symptoms were reduced greatly. Before, living with cats was nearly unbearable, with the itching, sneezing, watery eyes, inability to breathe, etc. Now, I can even play with the cats and I feel fine. Just a little bit of itching still occurs, and my nose isn't always perfectly clear. One day I went just over my 24 hour limit to see what would happen, and my allergic reactions came back with a vengence, so this medicine might have to be a full time thing for me, but it's better than my other options. | F | 18 | 50 days 10 mg 1X D | 11/1/2010 | 5 | Apparent allergies | I had no side effects at all from this drug. Sure if I sat still and did nothing I would get drowsy. I would take this medicine at approx. 1-2 pm each day. (after already being awake for 5-7 hours. So I think it was just mid day drowsiness. This stuff worked great compared to how i was suffering before taking it(cold like symptoms). One reviewer complained of suicidal thoughts, another said irratibility and bad/weird dreams? Sounds to me like you folks were taking Chantix or some other drug to help quit smoking since those are definitely side effects listed on Chantix/Zyban sheets. | I should add I began the attempt to quit smoking about the same time my "allergies" manifested themselves, so maybe the two were related. I havent had allergies since I was a little kid. I stopped taking the Zyrtec about two days ago and have not noticed any change in anyway so far as allergy symptoms coming back. Im thinking it was just a fluke as I was cleansing my body from 20+yrs of smoking. guess I will see in the coming week or so as the Zyrtec leaves my sytem. | M | 38 | 45 days 10mg 1X D | 5/31/2010 | 4 | Allergies | Well, I googled "Zyrtec side effects" because I've been really depressed and didn't understand why. I gained weight that I haven't been able to rationalize (about 10 lbs since Thanksgiving ). I've had extreme sadness and bouts of anger since Christmas. I've cried alot lately and I don't remember crying so much in the past. Today was the last straw when I yelled "I want a divorce" which I've NEVER said. I'm going off Zyrtec today and going back to Claritin and see what happens. | Zyrtec treated my allergies 100%. But these side effects are awful. | F | 41 | 45 days | 1/12/2009 | 1 | chroin autoimmune hives | irritability, irrational behavior, temper tantrums | My 5 year old daughter was prescribed zyrtec 3 years ago for the first time for her hives. I noticed extreme irrtibality when she started taking it and I took her off. I just kept giving her benadryl. She then started with hives this december and her doc recommended zyrtec again - end all and be all for hives - is what he said. I have noticed she does get irrtiable with her episodes of hives, so I thought that maybe my reaction to zyrtec was wrong. I started giving her zyrtec end of december until 2 days ago. She was having MAJOR temper tantrums, extremely irritability and would not even get dressed. It is tough for her to get dressed when she has her hives, but now she will not put anything on. Going to preschool is out of the question. I truly believe that it is the zyrtec that caused all the fights and heartache these past 2 months. She is becoming my daughter again. She still did not go to school today, had hard time getting dressed and she started getting irrtiable and then it | F | 32 | 45 days | 2/21/2008 | 1 | seasonal allergies | Behavior and mood changes (aggressive, moody, irritable). Skin irritations. | On a recommendation from our pediatrician, we gave this to our 2-year old son. We saw behavior changes, but thought it was simply the "terrible 2's". This should not be given to children!!! I'd be interested in hearing from other parents and what (if anything) you have found to give children for seasonal allergies. I am investigating more natural options from now on. | M | 2 | 45 days | 10/28/2008 | 1 | Seasonal Allergy | My 7 year old daughter become unable to focus, had trouble concentating in school, complained of headaches, became extremely unhappy, and experienced weight gain while on Zyrtec. And, thankfully within days of switching to Singular we are seeing "our daughter" back again. | The side effects are horrible! | F | 7 | 45 days | 10/8/2006 | 1 | Seasonal Allergy | My 7 year old daughter become unable to focus, had trouble concentating in school, complained of headaches, became extremely unhappy, and experienced weight gain while on Zyrtec. And, thankfully within days of switching to Singular we are seeing "our daughter" back again. | The side effects are horrible! | F | 7 | 45 days | 10/8/2006 | 1 | Seasonal allergies | Most severe: Extreme fatigue, extremely severe dizziness, inability to remain asleep, vivid/disturbing dreams. Less severe: Mood swings (sad to angry and back), mild depression, inability to concentrate for long periods. | The fatigue and extreme dizziness were the most debilitating side effects. Upon rising from bed, I was so dizzy that I actually fell several times before making the connection to Zyrtec and stopping it. I slept poorly and no amount of sleep would reduce the severe fatigue. Dizziness was worst upon rising, but was persistent to a lesser degree throughout the day. Mood and concentration may have been a side effect of the drug and/or the poor sleep and fatigue. Sadly, it does seem to work better on my allergies than anything else I've taken, but the negative side effects FAR, FAR outweigh its benefits. Symptoms resolved themselves within 2-3 days of stopping the medication. I'll just have to buy tissues and suffer. My nose may run, but at least the room won't be spinning all the time. | M | 45 | 45 days 10 mg 1X D | 5/18/2010 | 5 | allergy | no major side effect but i often drink beer when taking it and if i have beer or wine i get some of the strangest dreams they're always fun but wow there weird. | stuff works great | M | 27 | 40 days 30mg 1X D | 9/28/2011 | 4 | Allergies | Deep depression and muscle and joint pain. Could not walk without pain. Sleep disorder as well. Could not fall asleep and then waking up all through the night. | It helps with the allergies but the side effects are not worth it. | F | 53 | 40 days | 2/23/2009 | 3 | Hay fever | Sleep apnea! I had never experienced sleep apnea before. My wife reported that my breathing stopped periodically while I was sleeping. I woke up many times in the night, not knowing why. For me, poor sleep yields weight gain. | It's a shame. It did a great job of controlling my allergies. If they made a 12-hour version of the drug, it would be perfect! | M | 33 | 40 days | 5/13/2009 | 3 | seasonal allergies | Irregular heartbeat | I hate that this med causes this problem for me, because it worked fabulous on my post nasal issues. I just can't handle the skipping heartbeats. | F | 50 | 40 days 5 mg 1X D | 4/1/2010 | 3 | allergies (sneezing fits) | Worked well, but after several weeks I became so tired, it was a crisis if I had to do laundry. Stopped & after a couple of days started to get energy back. And pee better. | There is another effective allergy med. like this one: allegra. Both work well for me, and both have insidious side effects. It is peculiar both are sold over-the-counter, since inevitably both will lead to fruitless doctor visits and more burdens on the health care system. | M | 70 | 40 days 5 or 10 mg 1X D | 1/23/2013 | 2 | Allergies | Every time I got in my car to drive, I felt an overwhelming sleepiness come over me. I could not understand why I was experiencing this change in my behavior.When I decided to discontinue taking Zyrtec, my sleepiness while driving stopped. | F | 55 | 40 days 1X D | 1/27/2011 | 1 | allergies (cats, dust, ragweed) | exhaustion, feeling wiped-out, nightmares, irritability, unexplained anger, weight gain, difficult swallowing, thick congestion | I have never felt so exhausted. I took 5 or 10mg at night and on weekends I easily slept until 5pm. On weekdays I could barely get out of bed, let alone hold my head up at work. I just couldn't get enough sleep. I found myself so irritable, even enraged, didn't feel like myself at all. Yet, nothing "bad" had happened in my life. My allergist thought I was crazy during the 30 day check-in when I explained the exhaustion and crazy dreams, etc. I am going back to Alavert where I have no side effects. | F | 32 | 35 days 5 or 10mg 1X D | 10/19/2010 | 1 | my son's allergies | My 13 year old son started taking this medicine a little over a month ago and he has had mood swings and violent temper tantrums. I am not even sure if it helped his allergies. I am stopping this medicine immediately!! He is gifted and generous kid when not on this nedicine. Now he is a angry, negative brat. Hopefully, taking him off this medicine he will mellow out again and not be so mean and hurtful to all of us. I am so glad that I found this site!!! I wonder why Zrytec won't mention these side effects????!!! | I have already let my son's Doctor know about this terrible reaction to this!! I will never reccomd this medicine. I am also going to contact Zyrtec regarding this side effect. No one needs to be this miserable and unhappy and angry! | M | 13 | 32 days | 10/5/2005 | 1 | serve allergies | hard to wake up in morning, mood swings, irrational thoughts, crying, anti social | It didn't occur to me that my severe mood swings had anything to do with zyrtec until I realized how out of control I was behaving and I started searching for side effects. Now I have a reason for my weird dreams in the morning and the agitation I'm feeling. There hasn't been enough coffee in the morning to help me function. I was beginng to fear I couldn't do my job and my husband was beginning to believe I was a lunatic. | F | 59 | 31 days | 9/30/2007 | 1 | year-round allergies | Pounding heart, high blood pressure spikes, racing heart, extreme fatigue, chest pain | Helped allergies but side-effects sent me to ER thinking I was having a heart attack. Doctors said I had too much job stress. GP said I needed something for anxiety. My heart was pounding even when at rest. During the night I would wake up with a rapid fluttering. Thought I had heart trouble. I realized the problems started with the Zyrtec because I keep a blood pressure diary and it all coincides. Asked the pharmacist if Zyrtec could cause any of the symptoms I was having and had an AHA moment. All symptoms stopped after off of it for 4 days. When I get cold, I have an intense itch that I never had before. Hope that goes away. It is only where skin is exposed to cold - like face and hands. Will never use this drug again. | F | 59 | 31 days | 11/7/2009 | 5 | clear nasal congestion | dry mouth | excellent drug...worked much better than claritin for me..A+++ | M | 16 | 30 days | 11/7/2002 | 4 | Seasonal Allergies | A touch of anxiety upon initial usage | 10mg daily, Works great, it does take a bit of adjustment, however the pros outweigh the cons. Also prescribed Elestat (which suprisingly makes me feel a lot more strange than the Zyrtec) and Nasonex (this stuff works great). If you have seasonal allergies I would definately recommend this combo, only problem I notice is a touch of eye redness/itching (but rarely during the day). This is definately not for kids, and for sure exaggerates any existing conditions. If you are taking a bunch of other meds and already have psychological problems/tendancies you should lay off the pharms. | M | 25 | 30 days | 10/17/2007 | 4 | spring allergies | weight gain | Very effective at controlling my allergies. I'm perhaps a little drowsy, but I counter that by taking it at night and drinking coffee in the day. In another month, allergy season will end, and hopefully I'll be able to lose the weight. | M | 33 | 30 days | 4/30/2009 | 3 | pet and seasonal allergies | I've been taking it for a month it worked for a few weeks and then stopped, then I started to notice a change in myself. I've become very irratable and depressed. I'm tired and fatigued and sleep all the time. Also lately I've had a very dry nose and mouth and have had an increased appetite and have been gaining weight. I feel sick like I've got a cold and my asthma has been very bad. Guess what I looked all zytec side effects on the internet and I have about 80% of them. I am going to stop taking it immediately. | People thinking about taking this drug should research it on the internet. If you see how many side effects it has, you'll think twice about taking it. | F | 39 | 30 days | 10/17/2004 | 3 | Seasonal Allergies | My 6yr old daughter had problems last spring with vaginal irritation and discomfort when urinating. We took her to the pediatrician 3 x's and a Gyn and they came up with nothing. This spring, same problem - went online and found this site stating some females had similar problems w/Claritan. I called Pfizer this morning and they told me that skin irritation is side effect of med(which they included her problem as part of that side effect). Incidentally, 4 yr old son had strange rash on face after starting Zyrtec, maybe is related to med as well? | My daughter has terrible allergies, don't know what to do to relieve suffering - she missed several days of school last year due to vaginal irritation - not to mention Dr's asking her if anyone "touched" her. Terrible experience for parent! | F | 6 | 30 days | 4/25/2007 | 3 | sinus headaches | Graphic and disturbing dreams; some sluggishness | I started taking Zyrtec at night because I was waking up with sinus headaches every morning. It worked well for that, so I have rated it 3. It completely knocks me out, especially if I have had any alcohol at all, even a single glass of wine at dinner, and it takes me a while to get moving in the morning. I have constant, vivid, disturbing dreams almost every night. My husband told me I woke up after an hour last night saying, "Scared, scared" over and over. I have no memory of that. I am going to stop taking this, or at least cut the dosage in half. If you do take it, follow the label warnings - no alcohol. | F | 56 | 30 days 10mg 1X D | 2/20/2010 | 2 | allergy | elevated blood pressure, rapid heart beat(normally 70 BPM, went to90BPM)difficulty sleeping, easily angered with others. | Initially helped relieve a cough related allergy. Was very concerned with the high blood pressure( never had it before) and was preparing to see my MD. Even thought of going to hospital because I thought I could be on the verge of a heart attack. I mentioned symptoms to a friend who said it could be the zyrtec. Stopped taking it and three days later heart rate down to 80 BPM and blood pressure 140/100 down from 155/105. Im hoping for continued improvement back to my normal 120/80. Wow this stuff scared me! Never had any heart issues before this. Going to go back to Claritin which had barely any side affects. Fortunately no negstive withdrawal symptoms others have reported. | M | 59 | 30 days 10 mg 1X D | 3/28/2010 | 2 | seasonal allergies | trouble sleeping during the day during regular naptime, sore/dry throat, stomachace,loss of appetite, nosebleeds | My 2 1/2 year old was on Zyrtec liquid at night for 1 month and had these side effects. Once we went off Zyrtec, the issues stopped. Not happy. Not happy at all. | M | 2.5 | 30 days | 10/24/2006 | 2 | Seasonal Allergies | My 6-year-old daughter went from a happy, beautiful child to an emotional trainwreck. Allergies and puffy eyes went away, but in their place was a teary, depressed, befuddled and evil child who slammed doors, broke glass, and acted out verbally. | I am mortified that I put this poison in my daughter's body. After reading the other comments on this site, my heart goes out to all parents who tried to help their kids and, like me, turned them into monsters. My daughter has 10 days left in the school year, and she will attend with puffy eyes and a booger nose, and be her happy, normal self again. I'll spend the summer finding alternatives that let me keep my daughter sympton free AND happy. Any other parents, feel free to e:mail me! | F | 6 | 30 days | 5/21/2006 | 2 | Chronic sinusitis | Extreme irritability, drowsiness, itching in hands and arms, very hungry in mornings and no appetite later in day. | Went on this drug for sudden onset of allergies and sinusitis. Experienced some minor relief at first, but then symptoms got much worse and other problems, such as extreme irritability, started happening. Very strange that suddenly my appetite completely changed, starving in the morning, and then no hunger and almost nauseous in the evening. I took the medicine at night. | M | 52 | 30 days | 10/2/2007 | 2 | allergies | Increase in appetite and weight gain!!!! I couldnt undrstand why my clothes were getting snug even with my regular exercise. then i stop taking zytrec for a couple days and my appetite decrease tremendously. And I would have increase dream activity. | Although it did help with my allergies i am goin to discontinue use daily and only use when my symptoms are severe. | F | 37 | 30 days | 2/15/2008 | 2 | Allergies | My daughter was put onto Zyrtec for allergies and she has uncontrollable crying and anxiety. | F | 9 | 30 days | 2/20/2009 | 1 | Seasonal allergies, eczema | Severe mood changes, sleep disturbances | We started our 4 year old son on Zyrtec about 1 mo ago, due to a flare of his eczema and exacerbation of seasonal allergies. Initially, his eczema seemed to improve, and the only adverse effect of the med was some drowsiness in the AM. Then, after about 2 wks, his demeanor changed from happy to depressive and he whined and complained constantly. His behavior became increasingly hyperactive, aggressive and violent. We were puzzled, since he is normally a very happy, gentle, sweet and loving child. Our concerns grew stronger when his violent outbusts became more frequent, often leading to us having to physically restrain him in order to prevent his hitting and kicking us. His tantrums also increased in length, often lasting 30-40 min at a time, after which he would collapse on the floor sobbing and inconsolable. He exhibited defiant behavior, and his listening skills completely disintegrated. On a hunch, I decided to Google Zyrtec and mood changes, since the only thing that had changed | M | 30 days | 5/8/2008 | 1 | seasonal allergy | upset stomach, loose bowels, diarrhea. | Within two days of discontinuing Zyrtec, my symptoms disappeared. The drug was effective in minimizing my allergic problems, but for me, the side effects are not worth it. | M | 63 | 30 days | 5/21/2008 | 1 | Seasonal Allergies | Dizziness, Eye pain, fogginess, headache, stomach pain, extreme weight gain | I have been taking Zyrtec for close to 4 weeks. It really does help alleviate the allergy symptoms, however, since I started having it I have had terrible eye pain and dizziness when I try to focus. I get so tired during the day I feel as if I will pass out if I don't lie down, I can't function normally. I have been eating well and excercising and gaining weight like crazy.... It just dawned on me today that the only thing that has changed in the past month is that I started Zyrtec. I am going to the doctor tomorrow to get my eyes checked and to discuss this with him, I just want to feel normal again. | F | 40 | 30 days | 7/6/2008 | 1 | allergie | Blood in the urine,fog brain, kidney pain,low blood pressure,tired, feeling really weird...NO MORE ZYRTEC !!!! | M | 37 | 30 days | 5/11/2009 | 1 | Seasonal allergies | My 4 yr old daughter has experienced many of the same side effects as everyone else. | She was on Zyrtec about 2 years ago for about a year and started having terrible temper tantrums and they escalated over time. You could not reason with her at all and it was like she didn't even hear you (exorcist-like). The smallest thing would set her off. We stopped giving it to her because we didn't really see any benefit. Her mood changed dramatically but we just attributed it to getting out of the terrible twos and threes. We just started giving it to her again about a month ago and the violent behavior came back about a week ago. We never made the connection to Zyrtec until now. The light bulb went off on Tuesday that it might be the problem because her diet hadn't changed and nothing else had really changed. I found this website and was blown away at the postings. I looked at the side effects listed on the pamphlet from the pharmacy and the only thing it says related to behavior is possible change in mental status. I can't believe this medicine is now sold over the co | F | 39 | 30 days | 4/3/2008 | 1 | hives | extreme weight gain, ate when I wasn't hungry, swelling of eyes and mouth, tiredness, just not feeling like myself, felt out of it. | F | 44 | 30 days | 8/28/2007 | 1 | SEASONAL ALLERGIES | HAIR LOSS! ASIDE FROM DIZZINESS, SLEEPLESSNESS, LETHARGY, MY HAIR STARTED FALLING OUT WITH THE ROOT INTACT WITHIN A WEEK OF TAKING THIS MEDICATION. I HAD BLOODWORK DONE AND MY THYROID IS FINE. THIS IS THE ONLY NEW MEDICATION THAT I HAVE TAKEN. I STOPPED TAKING ZYRTEC AFTER A MONTH AFTER I FOUND THIS SITE AND READ THAT OTHERS HAD THE SAME PROBLEM. MY DOCTOR COULDN'T EXPLAIN IT BECAUSE IT IS NOT LISTED AS ONE OF THE TOP 10 SIDE EFFECTS. I AM STILL WAITING FOR MY HAIR TO STOP FALLING OUT BUT I SEE NO SIGNS OF IT SLOWING DOWN. | F | 54 | 30 days | 7/8/2007 | 1 | Allergys/Asthma | Been on zyrtec for a little over a month, twice daily, I am 26 and have never had any problems with my thick gorgeous hair, now I am loosing it in record timing. The drug works great if you dont mind going bald...Ladies I'm talking to you! | F | 26 | 30 days | 5/27/2007 | 1 | Allergies/Eczema | My daughter (21 months) was prescribed Zyrtec about a month ago for allergies. She's a very happy, sweet, loving child with the normal toddler challenges, but never anything unusual, nor aggresive. Well, that had all changed in the past month. We just kept telling ourselves that it must be the terrible two's - but this was bad, she would cry at the slightest thing, she almost stopped eating, she'd wake up crying at night and it would take hours to console her. She became aggresive (slapping, biting) and she was never like that before -- it finally hit me last Friday when she'd bit another child at daycare really hard that this just can't be normal and I can't say why I thought it, but that night I wondered if it could be the Zyrtec - it was the only change in her normal diet - so I went to web and typed in "Zyrtec & Mood Swings" and found this site - what a relief. we stopped her Zyrtec and by late yesterday (2 days later) she was back to her sweet self again. I'd rath | F | 2 | 30 days | 10/8/2007 |