Table of ContentsView AllTable of ContentsCommon Side EffectsLess Common Side EffectsRare Side EffectsOverdose SymptomsWho Should Not Take ItDosage and DirectionsAlternatives
Table of ContentsView All
View All
Table of Contents
Common Side Effects
Less Common Side Effects
Rare Side Effects
Overdose Symptoms
Who Should Not Take It
Dosage and Directions
Alternatives
Common side effects of Zyrtec (cetirizine) can include drowsiness, fatigue, dry mouth, sore throat, and dizziness. Less common side effects include headaches, and nausea.Diarrhea and coughing have also been observed in children.
Cetirizine, the active ingredient of Zyrtec, is a second-generationantihistaminethat blocks the action ofhistamine(a product of the immune system that triggers allergy symptoms). Zyrtec relieves the symptoms of seasonal allergies, including itchy eyes, nose, or throat, sneezing,runny nose,postnasal drip, andhives.
While Zyrtec side effects are typically mild, some rare serious side effects are possible, including irregular heartbeat and impaired urination.
In adults, common side effects when taking Zyrtec include:
Inchildren, common side effects also include:
The common side effects associated with Zyrtec tend to be mild and typically clear up quickly once the drug is stopped.
Interestingly, researchers have found that children tolerate cetirizine-related drowsiness better than adults.
How Long Does Zyrtec Stay in Your Body?With an elimination half-life of eight to nine hours, Zyrtec remains in your system for about two days.
How Long Does Zyrtec Stay in Your Body?
With an elimination half-life of eight to nine hours, Zyrtec remains in your system for about two days.
In adults, some less commonly experienced side effects associated with Zyrtec include:
Rare side effects from Zyrtec can include:
Anaphylaxisis possible when taking Zyrtec.
When to Call 911Rarely, Zyrtec can cause a potentially life-threatening, whole-body allergy known asanaphylaxis. Call 911 or go to your nearest emergency room if you experience any of the following symptoms after taking Zyrtec:Wheezingor shortness of breathSudden rash or hives(red, raised, blotchy skin)ItchingRapid or slowed heartbeatsDizziness, lightheadedness, or faintingSwelling of the face, tongue, lips, or throatNausea and vomitingA feeling of impending doom
When to Call 911
Rarely, Zyrtec can cause a potentially life-threatening, whole-body allergy known asanaphylaxis. Call 911 or go to your nearest emergency room if you experience any of the following symptoms after taking Zyrtec:Wheezingor shortness of breathSudden rash or hives(red, raised, blotchy skin)ItchingRapid or slowed heartbeatsDizziness, lightheadedness, or faintingSwelling of the face, tongue, lips, or throatNausea and vomitingA feeling of impending doom
Rarely, Zyrtec can cause a potentially life-threatening, whole-body allergy known asanaphylaxis. Call 911 or go to your nearest emergency room if you experience any of the following symptoms after taking Zyrtec:
Zyrtec Overdose Symptoms
Symptoms of a Zyrtec overdose may include:
Seek emergency medical attention or callPoison Controlat 1-800-222-1222 if you experience these symptoms while taking Zyrtec.
Who Should Not Take Zyrtec
Zyrtec is generally considered safe, but some people should not take the drugs due to the potential harm. Do not take Zyrtec if you:
Speak with your healthcare provider before using Zyrtec if you are pregnant, trying to become pregnant, or breastfeeding.
Zyrtec should not be taken with alcohol or marijuana. Doing so can increase the risk of drowsiness and can make driving or handling heavy equipment hazardous.
Zyrtec is available over-the-counter (OTC) as a tablet, chewable tablet, and syrup. Each dose is measured in milligrams (mg). There are recommended dosages for specific age groups.
Recommended dose for adults and children ages 6 to 64:
Recommended dose for children ages 2 to 5 and adults 65 and over:
Zyrtec is one of the safest antihistamines to use in adults 65 and over. However, the recommended dose of Zyrtec for those in this age group is lower than for younger adults. This is becauseallsecond-generation antihistamines are more likely to cause side effects (like sleepiness, anxiety, and tremors) in older people.
For children under 2:
Zyrtec is taken with or without food. Measure the syrup using the dosing syringe provided andnota kitchen spoon. Chewable tablets should be chewed and not swallowed whole.
Can Taking Zyrtec Daily Be Harmful?Zyrtec is safe to take daily and is generally regarded as safe for long-term use.There is a very small risk of liver toxicity with long-term use. While this is considered rare, anyone who uses Zyrtec on an ongoing basis should have theirliver enzymestested just in case.
Can Taking Zyrtec Daily Be Harmful?
Zyrtec is safe to take daily and is generally regarded as safe for long-term use.There is a very small risk of liver toxicity with long-term use. While this is considered rare, anyone who uses Zyrtec on an ongoing basis should have theirliver enzymestested just in case.
Alternatives to Zyrtec
If you cannot use Zyrtec, you can try another second-generation antihistamine likeAllegra (fexofenadine)orClaritin (loratadine). However, these OTC drugs have similar mechanisms of action to Zyrtec—and similar potential side effects. So, they may not be an option if you cannot tolerate the side effects of Zyrtec.
Somenon-drug alternativesmay prove beneficial during seasonal allergies, including:
Steaming Inhalation With Essential OilsAdding essential oils like eucalyptus, tea tree, and lavender to boiling water may help with seasonal allergy symptoms. Limited research has demonstrated that some essential oils can ease sinus inflammation.
Steaming Inhalation With Essential Oils
Adding essential oils like eucalyptus, tea tree, and lavender to boiling water may help with seasonal allergy symptoms. Limited research has demonstrated that some essential oils can ease sinus inflammation.
Summary
Zyrtec is a second-generation antihistamine used to relieve symptoms of seasonal allergies such as sneezing, runny nose, and itchy eyes. It is available OTC for use in adults and children.
Side effects can include drowsiness, dry mouth, sore throat, dizziness, and stomach pain. Serious side effects can include rapid or irregular heartbeat, mood changes such as anxiety, and problems urinating.
Zyrtec is an effective option for treating seasonal allergies and other allergic conditions. However, if your allergy symptoms are severe and Zyrtec fails to provide relief, ask your healthcare providers for a referral to anallergist(allergy specialist).
13 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Food and Drug Administration.Zyrtec (cetirizine hydrochloride) tablets and syrup for oral use.Parisi GF, Leonardi S, Ciprandi G, et al.Cetirizine use in childhood: an update of a friendly 30-year drug.Clin Mol Allergy. 2020;18:2. Published 2020 Feb 26. doi:10.1186/s12948-020-00118-5Corsico AG, Leonardi S, Licari A, et al.Focus on the cetirizine use in clinical practice: a reappraisal 30 years later.Multidiscip Respir Med.2019;14:40. doi:10.1186/s40248-019-0203-6Nakamura T, Hiraoka K, Harada R, Matsuzawa T, Ishikawa Y, Funaki Y,et al.Brain histamine H1 receptor occupancy after oral administration of desloratadine and loratadine.Pharmacol Res Perspect. 2019 Jul 12;7(4):e00499. doi:10.1002/prp2.499.Cetirizine. In:LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; January 16, 2017.American Academy of Allergy, Asthma, & Immunology.Anaphylaxis - Symptoms & Diagnosis.Thomas SHL.Antihistamine poisoning.Medicine. 2016;44(3):141-142. doi:https://doi.org/10.1016/j.mpmed.2015.12.002American Academy of Ophthalmology.Common Drugs That Can Worsen Glaucoma.UpToDate.Patient education: Benign prostatic hyperplasia (BPH) (Beyond the Basics).Bozek A.Pharmacological management of allergic rhinitis in the elderly.Drugs Aging.2017;34(1):21–8. doi:10.1007/s40266-016-0425-7Urdaneta ER, Patel MK, Franklin KB, Tian X, Wu MM.Assessment of different cetirizine dosing strategies on seasonal allergic rhinitis symptoms: findings of two randomized trials.Allergy Rhinol (Providence). 2018 Jan-Dec;9:2152656718783630. doi:10.1177/2152656718783630Vathanophas V, Pattamakajonpong P, Assanasen P, Suwanwech T.The effect of steam inhalation on nasal obstruction in patients with allergic rhinitis.Asian Pac J Allergy Immunol. 2021;39(4):304-308. doi:10.12932/AP-090818-0393Horváth G, Ács K.Essential oils in the treatment of respiratory tract diseases highlighting their role in bacterial infections and their anti-inflammatory action: A review.Flavour Fragr J. 2015;30(5):331-341. doi:10.1002/ffj.3252
13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Food and Drug Administration.Zyrtec (cetirizine hydrochloride) tablets and syrup for oral use.Parisi GF, Leonardi S, Ciprandi G, et al.Cetirizine use in childhood: an update of a friendly 30-year drug.Clin Mol Allergy. 2020;18:2. Published 2020 Feb 26. doi:10.1186/s12948-020-00118-5Corsico AG, Leonardi S, Licari A, et al.Focus on the cetirizine use in clinical practice: a reappraisal 30 years later.Multidiscip Respir Med.2019;14:40. doi:10.1186/s40248-019-0203-6Nakamura T, Hiraoka K, Harada R, Matsuzawa T, Ishikawa Y, Funaki Y,et al.Brain histamine H1 receptor occupancy after oral administration of desloratadine and loratadine.Pharmacol Res Perspect. 2019 Jul 12;7(4):e00499. doi:10.1002/prp2.499.Cetirizine. In:LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; January 16, 2017.American Academy of Allergy, Asthma, & Immunology.Anaphylaxis - Symptoms & Diagnosis.Thomas SHL.Antihistamine poisoning.Medicine. 2016;44(3):141-142. doi:https://doi.org/10.1016/j.mpmed.2015.12.002American Academy of Ophthalmology.Common Drugs That Can Worsen Glaucoma.UpToDate.Patient education: Benign prostatic hyperplasia (BPH) (Beyond the Basics).Bozek A.Pharmacological management of allergic rhinitis in the elderly.Drugs Aging.2017;34(1):21–8. doi:10.1007/s40266-016-0425-7Urdaneta ER, Patel MK, Franklin KB, Tian X, Wu MM.Assessment of different cetirizine dosing strategies on seasonal allergic rhinitis symptoms: findings of two randomized trials.Allergy Rhinol (Providence). 2018 Jan-Dec;9:2152656718783630. doi:10.1177/2152656718783630Vathanophas V, Pattamakajonpong P, Assanasen P, Suwanwech T.The effect of steam inhalation on nasal obstruction in patients with allergic rhinitis.Asian Pac J Allergy Immunol. 2021;39(4):304-308. doi:10.12932/AP-090818-0393Horváth G, Ács K.Essential oils in the treatment of respiratory tract diseases highlighting their role in bacterial infections and their anti-inflammatory action: A review.Flavour Fragr J. 2015;30(5):331-341. doi:10.1002/ffj.3252
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Food and Drug Administration.Zyrtec (cetirizine hydrochloride) tablets and syrup for oral use.Parisi GF, Leonardi S, Ciprandi G, et al.Cetirizine use in childhood: an update of a friendly 30-year drug.Clin Mol Allergy. 2020;18:2. Published 2020 Feb 26. doi:10.1186/s12948-020-00118-5Corsico AG, Leonardi S, Licari A, et al.Focus on the cetirizine use in clinical practice: a reappraisal 30 years later.Multidiscip Respir Med.2019;14:40. doi:10.1186/s40248-019-0203-6Nakamura T, Hiraoka K, Harada R, Matsuzawa T, Ishikawa Y, Funaki Y,et al.Brain histamine H1 receptor occupancy after oral administration of desloratadine and loratadine.Pharmacol Res Perspect. 2019 Jul 12;7(4):e00499. doi:10.1002/prp2.499.Cetirizine. In:LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; January 16, 2017.American Academy of Allergy, Asthma, & Immunology.Anaphylaxis - Symptoms & Diagnosis.Thomas SHL.Antihistamine poisoning.Medicine. 2016;44(3):141-142. doi:https://doi.org/10.1016/j.mpmed.2015.12.002American Academy of Ophthalmology.Common Drugs That Can Worsen Glaucoma.UpToDate.Patient education: Benign prostatic hyperplasia (BPH) (Beyond the Basics).Bozek A.Pharmacological management of allergic rhinitis in the elderly.Drugs Aging.2017;34(1):21–8. doi:10.1007/s40266-016-0425-7Urdaneta ER, Patel MK, Franklin KB, Tian X, Wu MM.Assessment of different cetirizine dosing strategies on seasonal allergic rhinitis symptoms: findings of two randomized trials.Allergy Rhinol (Providence). 2018 Jan-Dec;9:2152656718783630. doi:10.1177/2152656718783630Vathanophas V, Pattamakajonpong P, Assanasen P, Suwanwech T.The effect of steam inhalation on nasal obstruction in patients with allergic rhinitis.Asian Pac J Allergy Immunol. 2021;39(4):304-308. doi:10.12932/AP-090818-0393Horváth G, Ács K.Essential oils in the treatment of respiratory tract diseases highlighting their role in bacterial infections and their anti-inflammatory action: A review.Flavour Fragr J. 2015;30(5):331-341. doi:10.1002/ffj.3252
Food and Drug Administration.Zyrtec (cetirizine hydrochloride) tablets and syrup for oral use.
Parisi GF, Leonardi S, Ciprandi G, et al.Cetirizine use in childhood: an update of a friendly 30-year drug.Clin Mol Allergy. 2020;18:2. Published 2020 Feb 26. doi:10.1186/s12948-020-00118-5
Corsico AG, Leonardi S, Licari A, et al.Focus on the cetirizine use in clinical practice: a reappraisal 30 years later.Multidiscip Respir Med.2019;14:40. doi:10.1186/s40248-019-0203-6
Nakamura T, Hiraoka K, Harada R, Matsuzawa T, Ishikawa Y, Funaki Y,et al.Brain histamine H1 receptor occupancy after oral administration of desloratadine and loratadine.Pharmacol Res Perspect. 2019 Jul 12;7(4):e00499. doi:10.1002/prp2.499.
Cetirizine. In:LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; January 16, 2017.
American Academy of Allergy, Asthma, & Immunology.Anaphylaxis - Symptoms & Diagnosis.
Thomas SHL.Antihistamine poisoning.Medicine. 2016;44(3):141-142. doi:https://doi.org/10.1016/j.mpmed.2015.12.002
American Academy of Ophthalmology.Common Drugs That Can Worsen Glaucoma.
UpToDate.Patient education: Benign prostatic hyperplasia (BPH) (Beyond the Basics).
Bozek A.Pharmacological management of allergic rhinitis in the elderly.Drugs Aging.2017;34(1):21–8. doi:10.1007/s40266-016-0425-7
Urdaneta ER, Patel MK, Franklin KB, Tian X, Wu MM.Assessment of different cetirizine dosing strategies on seasonal allergic rhinitis symptoms: findings of two randomized trials.Allergy Rhinol (Providence). 2018 Jan-Dec;9:2152656718783630. doi:10.1177/2152656718783630
Vathanophas V, Pattamakajonpong P, Assanasen P, Suwanwech T.The effect of steam inhalation on nasal obstruction in patients with allergic rhinitis.Asian Pac J Allergy Immunol. 2021;39(4):304-308. doi:10.12932/AP-090818-0393
Horváth G, Ács K.Essential oils in the treatment of respiratory tract diseases highlighting their role in bacterial infections and their anti-inflammatory action: A review.Flavour Fragr J. 2015;30(5):331-341. doi:10.1002/ffj.3252
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