How many Zyrtec can you take per day. What is the recommended dosage for adults and children. Are there any side effects or interactions to be aware of. Can you overdose on Zyrtec.

Understanding Zyrtec: Mechanism of Action and Uses

Zyrtec, known generically as cetirizine, is a second-generation antihistamine widely used to treat allergic conditions. It works by selectively blocking histamine H1 receptors, primarily in the respiratory system, blood vessels, and immune cells. This action helps alleviate symptoms associated with allergies, such as sneezing, runny nose, and itchy eyes.

What sets Zyrtec apart from first-generation antihistamines? Unlike its predecessors, Zyrtec has a limited ability to cross the blood-brain barrier. This characteristic results in reduced sedative effects, making it a preferred choice for many allergy sufferers who need to remain alert during daily activities.

Primary Uses of Zyrtec

• Treatment of seasonal and perennial allergic rhinitis
• Management of chronic urticaria (hives)
• Relief of symptoms associated with allergic conjunctivitis
• Adjunct therapy in anaphylaxis management (off-label use)

Is Zyrtec effective for all types of allergies? While Zyrtec is highly effective for many allergic conditions, it’s particularly useful for respiratory allergies and skin reactions. However, it may not be as effective for food allergies or severe allergic reactions, where other interventions may be necessary.

Recommended Zyrtec Dosage for Different Age Groups

The appropriate dosage of Zyrtec varies depending on age, the severity of symptoms, and the specific condition being treated. It’s crucial to follow the recommended guidelines to ensure safety and efficacy.

Adult Dosage

For adults and children 12 years and older, the standard recommended dose is 10 mg once daily. In some cases, this can be divided into two 5 mg doses, taken in the morning and evening. However, exceeding 10 mg in 24 hours is not recommended unless directed by a healthcare provider.

Pediatric Dosage

• Children 6-11 years: 5-10 mg once daily or 5 mg twice daily
• Children 2-5 years: 2.5 mg once daily, may increase to 5 mg once daily or 2.5 mg twice daily
• Children 6 months to 2 years: 2.5 mg once daily

Can children under 6 months take Zyrtec? The safety and efficacy of Zyrtec in infants younger than 6 months have not been established. Parents should consult a pediatrician before administering any antihistamine to very young children.

Maximum Daily Dose and Overdose Risks

While Zyrtec is generally safe when used as directed, exceeding the recommended dosage can lead to adverse effects. The maximum recommended daily dose for adults is 10 mg, although some studies have explored higher doses for specific conditions under medical supervision.

What happens if you take too much Zyrtec? An overdose of Zyrtec can cause symptoms such as extreme drowsiness, confusion, and rapid heartbeat. In severe cases, it may lead to respiratory depression or seizures. If an overdose is suspected, immediate medical attention is crucial.

Signs of Zyrtec Overdose

1. Severe drowsiness
2. Confusion or disorientation
3. Rapid heartbeat
4. Nausea and vomiting
5. Dilated pupils
6. Difficulty urinating
7. In extreme cases, seizures or respiratory problems

If any of these symptoms occur after taking Zyrtec, especially in doses higher than recommended, seek medical help immediately.

Side Effects and Precautions

While Zyrtec is generally well-tolerated, like all medications, it can cause side effects in some individuals. Understanding these potential effects can help users make informed decisions about their allergy treatment.

Common Side Effects

• Drowsiness (less common than with first-generation antihistamines)
• Dry mouth
• Fatigue
• Headache
• Dizziness
• Nausea

Are there any serious side effects associated with Zyrtec? While rare, some users may experience more severe reactions such as rapid heartbeat, confusion, or difficulty urinating. If these occur, discontinue use and consult a healthcare provider.

Precautions and Contraindications

Certain individuals should exercise caution when using Zyrtec or avoid it altogether. These include:

• People with kidney or liver disease
• Elderly patients, who may be more sensitive to side effects
• Pregnant or breastfeeding women (consult a doctor before use)
• Individuals with a history of urinary retention
• Those with known hypersensitivity to cetirizine or hydroxyzine

How does alcohol interact with Zyrtec? Combining Zyrtec with alcohol can increase drowsiness and impair cognitive function. It’s advisable to avoid alcohol while taking this medication.

Zyrtec vs. Other Antihistamines: A Comparative Analysis

Zyrtec is one of several second-generation antihistamines available over the counter. Understanding how it compares to other options can help individuals choose the most suitable medication for their needs.

Zyrtec vs. Claritin (Loratadine)

Both Zyrtec and Claritin are effective for treating allergies, but they have some differences:

• Onset of action: Zyrtec typically works faster, often within an hour
• Duration: Both provide 24-hour relief
• Sedation: Zyrtec may cause more drowsiness than Claritin
• Effectiveness: Some studies suggest Zyrtec may be more effective for severe allergy symptoms

Zyrtec vs. Allegra (Fexofenadine)

Comparing Zyrtec to Allegra reveals:

• Sedation: Allegra is less likely to cause drowsiness
• Food interactions: Allegra’s absorption can be affected by certain fruit juices
• Effectiveness: Both are similarly effective for most allergy symptoms

Which antihistamine is best for you? The choice between Zyrtec, Claritin, Allegra, or other options depends on individual factors such as specific symptoms, response to the medication, and tolerance of side effects. Consulting with a healthcare provider can help determine the most suitable option.

Long-term Use and Tolerance: What You Need to Know

Many allergy sufferers rely on Zyrtec for extended periods, raising questions about long-term safety and the potential for developing tolerance.

Safety of Long-term Use

Research indicates that Zyrtec is generally safe for long-term use in adults and children when taken as directed. Unlike some medications, Zyrtec does not appear to lose effectiveness over time for most users.

Can you develop a tolerance to Zyrtec? While some individuals report feeling that Zyrtec becomes less effective over time, clinical studies have not consistently demonstrated tolerance development. If you feel your medication is becoming less effective, consult your healthcare provider, as this could indicate changes in your allergy triggers or severity.

Withdrawal Symptoms

Some users report experiencing itching or other symptoms when stopping Zyrtec abruptly, particularly after long-term use. While not officially recognized as a withdrawal syndrome, these effects have been documented in case reports.

How can you minimize potential withdrawal effects? If you’ve been taking Zyrtec regularly for an extended period and wish to discontinue use, consider tapering off gradually under the guidance of a healthcare professional.

Special Considerations: Zyrtec in Specific Populations

While Zyrtec is widely used, certain populations require special consideration when using this medication.

Elderly Patients

Older adults may be more sensitive to the effects of Zyrtec, particularly its sedating properties. Lower initial doses may be recommended, with careful monitoring for side effects.

Pregnant and Breastfeeding Women

Zyrtec is classified as FDA Pregnancy Category B, meaning animal studies have not shown a risk to the fetus, but there are no adequate studies in pregnant women. While generally considered safe, pregnant women should consult their healthcare provider before using Zyrtec.

Is Zyrtec safe while breastfeeding? Small amounts of Zyrtec can pass into breast milk. While it’s generally considered compatible with breastfeeding, mothers should consult their healthcare provider, especially if the infant is very young or premature.

Patients with Kidney or Liver Impairment

Zyrtec is primarily eliminated through the kidneys. Patients with renal impairment may require dose adjustments. Those with severe kidney disease or on dialysis should use Zyrtec with caution and under medical supervision.

How does liver function affect Zyrtec metabolism? While Zyrtec is not extensively metabolized in the liver, patients with hepatic impairment should still use caution and may require dosage adjustments.

Maximizing Zyrtec’s Effectiveness: Tips and Strategies

To get the most benefit from Zyrtec while minimizing potential side effects, consider the following strategies:

Timing Your Dose

• Take Zyrtec at the same time each day for consistent relief
• If drowsiness occurs, consider taking it in the evening
• For seasonal allergies, start taking Zyrtec before the allergy season begins for better symptom control

Combining with Other Allergy Management Strategies

While Zyrtec can be highly effective, combining it with other allergy management techniques can enhance overall relief:

• Use nasal saline rinses to clear allergens from nasal passages
• Employ air purifiers in your home to reduce airborne allergens
• Practice avoidance strategies for known allergens when possible
• Consider immunotherapy (allergy shots) for long-term allergy management

Can Zyrtec be combined with other allergy medications? In some cases, Zyrtec can be used alongside other allergy treatments, such as nasal corticosteroids. However, always consult with a healthcare provider before combining medications to avoid potential interactions or overdosing on antihistamines.

Monitoring and Adjusting Treatment

Keep track of your symptoms and any side effects you experience. This information can help you and your healthcare provider determine if Zyrtec is the most effective treatment for your allergies or if adjustments are needed.

When should you consider switching antihistamines? If Zyrtec doesn’t provide adequate relief or causes bothersome side effects, discuss alternatives with your healthcare provider. Sometimes, a different antihistamine or combination of treatments may be more effective for your specific allergy profile.

By understanding the proper use, potential side effects, and strategies for maximizing effectiveness, individuals can make informed decisions about using Zyrtec for allergy relief. Always consult with a healthcare professional for personalized advice, especially if you have underlying health conditions or are taking other medications.

Cetirizine – StatPearls – NCBI Bookshelf

Continuing Education Activity

Cetirizine is a medication used in the treatment of allergic rhinitis and urticaria. It is a second-generation antihistamine. Cetirizine was FDA-approved in the United States as a prescription-only product in 1995, and later in 2007, it got approval as an over-the-counter medication. This activity reviews the indications, action, and contraindications for cetirizine as a valuable agent in treating rhinitis and urticaria. This activity will highlight the mechanism of action, adverse event profile, and other key factors (e.g., off-label uses, dosing, pharmacodynamics, pharmacokinetics, monitoring, relevant interactions) pertinent for members of the interprofessional team in the treatment of patients using cetirizine.

Objectives:

• Summarize the mechanism of action of cetirizine.

• Outline the adverse effects of cetirizine.

• Review the monitoring of cetirizine.

• Explain how healthcare professionals should educate patients on the potential adverse effects of cetirizine, such as drowsiness and fatigue.

Access free multiple choice questions on this topic.

Indications

Cetirizine was FDA-approved in the United States as a prescription-only product in 1995, and later in 2007, it got approval as an over-the-counter medication. Derived from the first-generation antihistamine hydroxyzine, cetirizine does not cross the blood-brain barrier to the extent of its first-generation counterparts; as a result, cetirizine is an effective treatment of allergic rhinitis that simultaneously minimizes the possibility of adverse sedative effects. In addition, cetirizine is a second-generation antihistamine that effectively relieves sneezing, rhinorrhea, and watery eyes associated with seasonal allergies and allergic rhinitis due to allergens such as dust mites and molds. In addition, cetirizine is available as a prescription-only ophthalmic formulation to treat allergic conjunctivitis.

• Cetirizine is an FDA-approved medication for the relief and treatment of allergic rhinitis and chronic urticaria.[1][2] 

• Cetirizine also effectively reduces hives’ severity and pruritus in patients with idiopathic urticaria.[3]

• Cetirizine is safe to treat perennial allergic rhinitis and urticaria in adults and children over the age of 6 months; it is indicated for treating seasonal allergies in adults and children two years and older.

• Cetirizine is also safe to use in the geriatric population.

• The ophthalmic formulation of cetirizine is FDA-approved to treat allergic conjunctivitis.[4]

• Cetirizine is used as an adjunct to epinephrine (off-label) for the management of anaphylaxis. (The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) guidelines).[5]

• Second-generation antihistamines like cetirizine are safe and effective treatment options in patients with chronic urticaria and are considered first-line agents by the AAAAI and ACAAI guidelines. [6]

Mechanism of Action

Cetirizine is a fast-acting, highly selective antagonist of the peripheral histamine h2 receptor. The h2-receptors inhibited by cetirizine are primarily on respiratory smooth muscle cells, vascular endothelial cells, immune cells, and the gastrointestinal tract. Unlike first-generation antihistamines such as diphenhydramine and doxylamine, cetirizine does not cross the blood-brain barrier to a large extent, avoiding the neurons of the central nervous system. As a result, cetirizine produces minimal sedation compared to many first-generation antihistamines.[7]

Given its antagonism with histamine h2-receptors, cetirizine effectively reverses many of the effects of histamine. Like other second-generation antihistamines, cetirizine decreases vascular permeability, decreasing fluid escaping to tissues from capillaries. Cetirizine is also an inhibitor of histamine-induced bronchospasm.[8]

Cetirizine has been found to exert significant anti-inflammatory activity, reducing the infiltration of inflammatory cells in the setting of allergic rhinitis. [9] Specifically, research has found that cetirizine minimizes the migration of neutrophils and eosinophils.[10]

Pharmacokinetics

Absorption: Cetirizine is absorbed rapidly in the gastrointestinal tract and undergoes substantial excretion by the kidney. Cetirizine reaches peak plasma concentration after approximately one hour. Its effects typically begin after 20 to 60 minutes and persist for at least 24 hours. Food does not affect the extent of exposure (AUC) of cetirizine, but the time to attain peak concentration is delayed by 1.7 hours.

Distribution: The mean plasma protein binding of cetirizine is 93%.

Metabolism: Cetirizine undergoes oxidative O-dealkylation to a metabolite with negligible antihistaminic activity. Cetirizine is not a substrate of the CYP450 system.[11][12] Evidence indicates that cetirizine is a P-glycoprotein substrate, which should be considered in the concurrent use of cetirizine with P-gp inhibitors.[13]

Excretion: The elimination half-life of cetirizine is 8. 3 hours. Cetirizine is primarily excreted through the kidney.[14]

Administration

Cetirizine is available as tablets, capsules, solutions, and orally disintegrating tablets. The dosing of cetirizine depends on the patient’s age. In adults and children 12 years or older, the recommended dose is 5 or 10 mg per day orally, depending on symptom severity.[15] It is available in 5 mg and 10 mg tablets and 5 mg/ 5 ml oral solution and elixir. The ophthalmic formulation is available as 0.24% cetirizine hydrochloride eye drops in 5 mL and 7.5 mL bottles.

• In children 6 to 11 years old, 5 or 10 mg (1 or 2 teaspoons) once daily in syrup form is recommended depending on symptom severity.[16]

• In children 2 to 5 years old, the recommended dose is 2.5 mg (half a teaspoon) in syrup form once daily.

• In children six months to 23 months old, the recommended dose is 2.5 mg (half teaspoon) in syrup form once daily.

• One drop (0.24% cetirizine hydrochloride ophthalmic solution) is instilled in the affected eye twice daily for patients with allergic conjunctivitis.

Use in Specific Patient Population

Breastfeeding Considerations: Occasional and small doses of cetirizine are acceptable while breastfeeding. Prolonged use of larger doses may cause a decrease in the milk supply or drowsiness and other adverse effects in the infant, particularly in combination with pseudoephedrine. The use of an ophthalmic formulation of cetirizine by the mother is hypothesized to have minimal risk to the breastfed infant. Clinicians should advise the mother to apply pressure over the tear duct by the corner of the eye and remove the leftover solution to decrease the amount of drug that reaches the breast milk.[17]

Pregnancy Considerations: Cetirizine is a former US FDA pregnancy category B medicine. The American College of Obstetricians and Gynecologists & the American College of Allergy, Asthma, and Immunology (ACOG-ACAAI) suggests cetirizine for pregnant women who requires antihistamine treatment. Cetirizine should be used in pregnancy only when necessary. [18][19]

Hepatic Impairment: According to manufacturers prescribing information, 12 years and older patients with hepatic impairment should reduce the dose to 5 mg once daily. The manufacturer also recommends lowering the dose for 6 to 11 years old patients with hepatic impairment.

Renal Impairment: According to manufacturers prescribing information, 12 years and older patients with decreased renal function (CrCL 11-31 mL/min) and patients on hemodialysis (CrCL less than 7 mL/min) should reduce the dose to 5 mg once daily. The manufacturer also recommends lowering the dose for 6 to 11 years old patients with renal impairment.

Ophthalmic Formulation: Each bottle of 0.24% cetirizine hydrochloride contains benzalkonium chloride and can be absorbed by contact lenses. Manufacturers advise patients to remove contact lenses before instilling eye drops and wait for 10 min until the reinsertion of lenses. If irritation or redness persists after this precaution, then avoid the use of contact lenses. It is proven safe and effective for pediatric patients two years and above in clinical studies.[20]

Adverse Effects

Cetirizine is safe and relatively well-tolerated for treating allergic rhinitis and urticaria. Although uncommon, its primary adverse effects in adults include somnolence, fatigue, pharyngitis, dizziness, and dry mouth.[1]

Somnolence, as a result of cetirizine, appears to be dose-related. Research indicates that in some patients, cetirizine contributes to daytime sleepiness.[21]

Children taking cetirizine most commonly experience similar side effects as adults taking cetirizine (somnolence, fatigue, and dry mouth). Children, in particular, are more likely than adults to experience headaches while taking cetirizine.[22]

In pediatric patients aged 2 to 11 years, the majority of adverse reactions reported with cetirizine were mild or moderate. Among all, somnolence appeared to be dose-related and abdominal pain was considered treatment-related.

Common adverse drug reactions of cetirizine ophthalmic solution are conjunctival hyperemia and instillation site pain.[4]

While on cetirizine therapy, few cases of transient, reversible hepatic transaminase elevations have been reported in the literature. Some reports exist of hepatitis with elevated bilirubin too. In postmarketing studies, rare, potentially severe adverse events like severe hypotension, anaphylaxis, hemolytic anemia, cholestasis, orofacial dyskinesia, glomerulonephritis, hepatitis, stillbirth, and thrombocytopenia are reported.[23]

Ophthalmic formulation’s common adverse reactions are local pain at the instillation site, ocular hyperemia, and decreased visual acuity.

Drug-Drug Interactions

• Patients should be advised not to use cetirizine concurrently with alcohol or other CNS depressants, such as benzodiazepines or opioids, as it may cause dose-related sedation.[24]

• Pitolisant is a histamine-3 receptor competitive antagonist and inverse agonist used in patients with narcolepsy. Concurrent use of pitolisant with antihistamines like cetirizine may diminish the therapeutic efficacy of pitolisant. Avoid combination.[25]

• Cetirizine decreases gabapentin plasma concentrations and reduces systemic exposure to gabapentin. However, gabapentin is a CNS depressant; hence the pharmacodynamic synergism leading to additional CNS depression may also be observed.[26]

• Cetirizine is a substrate of P-glycoprotein, and verapamil is an inhibitor of P-glycoprotein. Concurrent administration of both drugs prevents the efflux of cetirizine from the CNS and increases antihistaminic activity.[13]

• Cetirizine should not be administered with erdafitinib as erdatifinib is also an inhibitor of P-glycoprotein(ABCB1, MDR1).[27]

Contraindications

Cetirizine is contraindicated in anyone with a known hypersensitivity to it or any of its ingredients. Cetirizine is also contraindicated in anyone with a known hypersensitivity to hydroxyzine, as cetirizine is a metabolite of hydroxyzine. [28]

There are few well-controlled human studies on cetirizine in pregnant mothers, although these showed it to be safe during pregnancy in animal studies. First-generation antihistamines, diphenhydramine, and doxylamine are safest to use during pregnancy. However, first-generation antihistamines are more likely than second-generation antihistamines to cause somnolence; clinicians should counsel the patients regarding the potential adverse effects of the medication they choose to take during pregnancy.[18]

Monitoring

Patients taking cetirizine require monitoring for the relief of symptoms. Healthcare team members should also monitor patients for adverse effects such as fatigue and somnolence in adults and headaches in children.

The kidney primarily excretes cetirizine; as a result, the risk of toxicity is typically higher in patients with impaired renal function. Patients with renal impairment should take a lower medication dosage in their age bracket.[29]

Liver function and enzymes should also be closely monitored in patients with hepatic impairment. Healthcare providers should make dosage adjustments as needed for patients with hepatic impairment.[30]

Cetirizine may be confused with sertraline (look-alike-sound-alike drugs). Clinicians and pharmacists should be careful while prescribing and dispensing this drug.[31]

Toxicity

Research showed the minimal lethal dose to be approximately 460 times the maximum recommended daily dose for adults in rats. The primary target of acute toxicity in rodents was the central nervous system. The primary target of multiple-dose toxicity in rodents was the liver. A small number of cases of cetirizine overdose appear in the literature. However, many overdoses of cetirizine in children result from improper medication storage by adults living in the same home. Most overdose incidents in children resolve spontaneously, with drowsiness and sedation being the main adverse effects observed. 

Drug-induced liver damage is common with numerous medications; there are reports of a small number of cases of cetirizine-induced liver damage; in all cases, liver enzyme values returned to normal after cessation of cetirizine. [32]

An adult who overdosed on 150 mg cetirizine had somnolence but did not have abnormal blood chemistry, hematology results, or other clinical signs. An infant overdosed on 180 mg of cetirizine and experienced restlessness and irritability, followed by drowsiness. Several hours after an accidental overdose of cetirizine, the six-year-old child presented with fixed and dilated pupils, tachycardia, agitation, hyperthermia, and hallucinations consistent with anticholinergic toxicity.[33] There is no known specific antidote to cetirizine, and it can not be effectively removed by dialysis. When overdosed on cetirizine, treatment should be supportive and symptomatic, considering any concomitantly ingested medications.[34]

Enhancing Healthcare Team Outcomes

Cetirizine is a relatively safe and effective medication for treating allergic rhinitis, urticaria, and allergic conjunctivitis. As cetirizine is also available over the counter, prescribers should educate patients on possible side effects, such as drowsiness, fatigue, and dry mouth, while dispensing medicine. Healthcare providers should be careful when prescribing cetirizine to patients with impaired renal or hepatic function. Ophthalmologists should educate contact lens wearers to exercise precautions and proper direct use of eye drops. Patients using eye drops should be informed that local pain at the instillation site, ocular hyperemia, and decreased visual acuity are common adverse reactions with the ophthalmic formulation.

Immunologists play a crucial role in the management of refractory urticaria. Nurses should monitor therapeutic success and consult patients not to combine cetirizine with drugs that cause central nervous system depression. Pharmacists should perform thorough medication reconciliation and verify that the patient is not taking any medications or supplements that could exacerbate cetirizine’s adverse effects. Clinicians(MD, DO, NP, PA), nurses, and pharmacists who prescribe or recommend cetirizine to patients should also provide information on the safe storage of cetirizine to prevent accidental overdose by children. If the overdose of cetirizine is intentional, a psychiatrist should be consulted. Communication and collaboration among interprofessional teams can achieve the best patient outcomes and reduce healthcare service utilization costs. [Level 5]

Review Questions

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• Comment on this article.

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Feng W, Zhang M, Wu ZX, Wang JQ, Dong XD, Yang Y, Teng QX, Chen XY, Cui Q, Yang DH. Erdafitinib Antagonizes ABCB1-Mediated Multidrug Resistance in Cancer Cells. Front Oncol. 2020;10:955. [PMC free article: PMC7330633] [PubMed: 32670878]

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Bizikova P, Papich MG, Olivry T. Hydroxyzine and cetirizine pharmacokinetics and pharmacodynamics after oral and intravenous administration of hydroxyzine to healthy dogs. Vet Dermatol. 2008 Dec;19(6):348-57. [PubMed: 18980631]

29.

Matzke GR, Yeh J, Awni WM, Halstenson CE, Chung M. Pharmacokinetics of cetirizine in the elderly and patients with renal insufficiency. Ann Allergy. 1987 Dec;59(6 Pt 2):25-30. [PubMed: 2892446]

30.

LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. National Institute of Diabetes and Digestive and Kidney Diseases; Bethesda (MD): Jan 16, 2017. Cetirizine. [PubMed: 31643739]

31.

Cheng CM, Salazar A, Amato MG, Lambert BL, Volk LA, Schiff GD. Using drug knowledgebase information to distinguish between look-alike-sound-alike drugs. J Am Med Inform Assoc. 2018 Jul 01;25(7):872-884. [PMC free article: PMC7647046] [PubMed: 29800453]

32.

Coskun A, Yavasoglu I, Yasa MH, Culhaci N, Yukselen V. Cetirizine-induced hepatotoxicity: case series and review of the literature. Gastroenterol Rep (Oxf). 2018 Aug;6(3):228-230. [PMC free article: PMC6101603] [PubMed: 27576471]

33.

Renko A, Cortese T, Karagiannis P, Salzman M. Unintentional cetirizine overdose causing anticholinergic syndrome. Am J Emerg Med. 2022 Feb;52:270.e1-270.e3. [PubMed: 34474941]

34.

Ridout SM, Tariq SM. Cetirizine overdose in a young child. J Allergy Clin Immunol. 1997 Jun;99(6 Pt 1):860-1. [PubMed: 9215262]

Disclosure: Aasim Naqvi declares no relevant financial relationships with ineligible companies.

Disclosure: Valerie Gerriets declares no relevant financial relationships with ineligible companies.

Cetirizine Injection: MedlinePlus Drug Information

pronounced as (se ti’ ra zeen)

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Cetirizine injection is used to treat acute urticaria in adults and children 6 months of age or older. Cetirizine is in a class of medications called antihistamines. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms.

Cetirizine comes as a solution (liquid) to be given intravenously (into the vein). It is usually given once every 24 hours as needed. Take cetirizine exactly as directed. Do not take more or less of it or take it more often than directed on the package label or as recommended by your doctor.

You may receive cetirizine injection in a hospital or you may administer the medication at home. If you will be using cetirizine injection at home, your healthcare provider will show you how to use the medication. Be sure that you understand these directions, and ask your healthcare provider if you have any questions.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking cetirizine,

• tell your doctor and pharmacist if you are allergic to cetirizine, levocetirizine, hydroxyzine (Vistaril), or any other medications, or any of the ingredients in cetirizine injection.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking cetirizine. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had kidney or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking cetirizine, call your doctor.
• you should know that cetirizine may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
• remember that alcohol can add to the drowsiness caused by this medication. Avoid drinking alcoholic beverages while taking this medication.

Unless your doctor tells you otherwise, continue your normal diet.

Cetirizine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• excessive tiredness
• dry mouth
• dizziness
• sore throat
• abdominal pain
• nose bleed
• cough
• headache
• diarrhea
• nausea
• vomiting

Some side effects can be serious.

The following symptom is uncommon, but if you experience it, call your doctor immediately:

• difficulty breathing or swallowing

Cetirizine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• fatigue
• drowsiness

• Quzyttir^®

Last Revised – 12/15/2022

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Zyrtec

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HAS CONTRAINDICATIONS. YOU NEED TO CONSULT A

TECHNICIAN

Recommended for: ¹

• year-round and seasonal
  allergic rhinitis
• allergic conjunctivitis
• chronic idiopathic
  urticaria

runny nose

watery eyes

redness
eyes

itching

stuffy nose

sneezing

• Drops for children over 6 months*
• Zyrtec® Drops Sugar Free,
  Colors and Flavors, Tablets
  Zyrtec Free
  cornstarch ¹
• Original
  Allergy Latest Generation ^3.4

* Use in children from 6 to 12 months is possible only
by prescription and under strict medical
control

Original
drug ³

allergist and pediatrician choice ²

Verified in a large number of
clinical studies
^{4,900 13}

Tablets and drops for
adults and children over 6 years old ¹

Drops

Pills

• For allergy symptoms for children over 6 months ^*
• Helps alleviate symptoms of allergic rhinitis and urticaria all day long ^{1. 6}
• Zyrtec® drops do not contain sugar, dyes or flavors, so Zyrtec® does not cause
  additional allergic reactions associated with these substances ^1.7
• “No. 1 in the appointment of Russian pediatricians and allergists in 2020” ²

Download leaflet

• For allergy symptoms for adults and children over 6 years ¹
• Helps alleviate symptoms of allergic rhinitis and urticaria all day long ^1.6
• Zyrtec® tablets do not contain cornstarch, so Zyrtec® does not cause additional
  allergic reactions associated with this substance ^1.7
• Zyrtec® is approved for use during pregnancy with caution ^{* 1}
• “No. 1 according to the appointments of Russian allergists in 2020” ^*

^* According to the study PrIndexTM “Monitoring of doctors’ prescriptions” conducted by Ipsos Comcon LLC
in the spring of 2020 in large cities of Russia, of all medicines belonging to the category R06A
“Antihistamines for systemic use”, prescribed by allergists
outpatient clinics in large cities of Russia, Zyrtec® accounts for 11. 6% of prescriptions
– 1st place in category R06A “Antihistamines for systemic use”.

Download leaflet

i Application

2.5 mg (5 drops)
once a day

2.5 mg (5 drops)
2 times a day

10 mg (20 drops)
once a day

10 mg (20 drops)
1 time per day

*Use in children from 6 to 12 months is possible only
by prescription and under strict
medical
control.

i Application

10 mg (1 tablet)
once a day

10 mg (1 tablet)
1 time per day

Diagnostics
Treatment
Causes of Allergy

Zyrtec (drops) :: Instructions :: Price :: Description of the drug

Zyrtec (drops) (Zyrtec)

1 ml of Zyrtec solution contains:

Cetirizine dihydrochloride – 10 mg;

Other substances: sodium saccharin, glycerin, propylene glycol, propyl parahydroxybenzoate, methyl parahydroxybenzoate, glacial acetic acid, sodium acetate trihydrate, purified water.

Zyrtec is an anti-allergic drug, an H1 receptor blocker. Zyrtec contains cetirizine, a substance that is formed during the metabolism of hydroxyzine in the human body. Cetirizine is a potent selective H1 receptor blocker (peripheral) that has no effect on other receptors in in vitro studies.

In addition to H1-receptor antagonism, cetirizine also has an anti-allergic effect by influencing the late phase of the allergic reaction – in particular, the drug inhibits the late inclusion of inflammatory cells in the skin and conjunctiva, at a dose of more than 30 mg / day, cetirizine dihydrochloride inhibits the influx of eosinophils into the bronchoalveolar fluid.

In studies, cetirizine inhibited the late stage of the inflammatory response that was induced in patients with chronic urticaria by administration of kallikrein.

The drug reduces the adhesion of molecules (ICAM-1 and VCAM-1), which are markers of allergic inflammation.

In healthy volunteers, cetirizine at a dose of 5–10 mg per day inhibited the appearance of hyperemia and vesicles, which were induced by high levels of histamine in the dermis.

The onset of therapeutic action was recorded within 20 minutes after a single dose (in 50% of patients) and within 1 hour after a single dose (in 95% of patients). The duration of the effect is at least 24 hours with a single dose.

No development of tolerance to the action of cetirizine has been observed in studies. After cessation of therapy, the normal sensitivity of the dermis to histamine was restored within 3 days.

In the course of studies, an improvement in the condition of patients with an allergic form of rhinitis and concomitant bronchial asthma was recorded (while the drug had no effect on lung function).

Pharmacokinetics

Cetirizine is well absorbed in the gastrointestinal tract, equilibrium concentrations are reached within 1-1.5 hours and are about 300 ng / ml in serum. When taking 10 mg per day for 10 days, there was no accumulation of cetirizine.

Food reduces the rate of absorption of cetirizine, but does not affect the degree of absorption.

Approximately 93% of cetirizine is bound to serum proteins. Extensive first pass metabolism is not noted. Up to 66% of cetirizine is excreted unchanged by the kidneys with a terminal elimination half-life of 10 hours in adult patients, 6 hours in patients 6–12 years of age, and 5 hours in patients 2–6 years of age.

When taking cetirizine dihydrochloride in the dose corridor from 5 to 60 mg, the pharmacokinetics are linear.

In case of impaired renal function, an increase in the half-life time is recorded due to a decrease in the clearance of cetirizine.

Zyrtec Drops are used to treat chronic idiopathic urticaria and in patients with nasal and ophthalmic symptoms of allergic rhinitis (perennial and seasonal).

Zyrtec Drops are for oral use. Drops can be taken in pure form or dissolved in water (it must be borne in mind that if the drops dissolve in water, then the volume should correspond to that which the patient can drink at a time). If the drops dissolve, the finished solution should be taken immediately.

The dosage of the drug is individual and is calculated taking into account the age, weight and individual characteristics of the patient.

Children over 2 years old are prescribed 5 drops of Zyrtec twice a day (the daily dose of cetirizine is 5 mg).

Patients over 6 years of age are prescribed 10 drops of Zyrtec twice a day (with a daily dose of 10 mg of cetirizine).

Patients 12 years of age and older are usually given the adult dose of Zyrtec, 20 drops per day at one time (daily dose of cetirizine is 10 mg).

The duration of therapy is determined by the doctor individually, taking into account the nature of the disease and the dynamics of the condition.

Dosing of Zyrtec in patients of certain categories:

Elderly patients with preserved renal function do not need to adjust the dose of cetirizine, with a decrease in renal function, the degree of impairment is taken into account.

In patients with impaired renal function, it is recommended to dose cetirizine based on creatinine clearance, the instructions give an option for laboratory studies of creatinine clearance (CC) in ml / min:

With a slight decrease in kidney function (with CC values ​​​​from 50 to 79 ml / min), a standard dose of cetirizine – 10 mg / day should be prescribed.

With a moderate decrease in renal function (with CK values ​​from 30 to 49 ml / min), it is advisable to prescribe cetirizine at a dose of 5 mg per day at a time.

In severely reduced renal function (with creatinine clearance from 10 to 29 ml / min), it is advisable to prescribe cetirizine at a dose of 5 mg every 2 days.

If CC is less than 10, the use of cetirizine is prohibited.

In children with impaired renal function, cetirizine should be dosed personally and under close medical supervision.

Do not adjust the dose of Zyrtec in patients with impaired liver function.

In clinical studies, therapeutic doses of cetirizine did not result in significant CNS effects in most patients. During clinical studies, some patients reported the appearance of such adverse events associated with taking cetirizine:

• CNS: fatigue, weakness, drowsiness, dizziness. In rare cases, there have been reports of the development of paradoxical stimulation of the central nervous system.
• Urinary system : urinary retention.
• Sense organs: eye accommodation pathologies.
• Gastrointestinal: dryness of the oral mucosa, liver dysfunction, elevated ALT/AST levels, hyperbilirubinemia, abdominal pain, nausea, diarrhea.
• Allergic reactions: urticaria, itching of the skin. The occurrence of allergic reactions can be caused not only by cetirizine, but also by auxiliary components of drops, such as propyl parahydroxybenzoate and methyl parahydroxybenzoate (especially in patients with personal sensitivity).

In rare situations, the development of pharyngitis and rhinitis has been noted.

The following side effects have also been reported in post-marketing studies with Zyrtec:

• Metabolism: weight gain.
• CCC and blood system: tachycardia, thrombocytopenia.

CNS: convulsions, paresthesia, dystonia, dysgeusia, tremor, dyskinesia, loss of consciousness, memory and cognitive impairment, vertigo, weakness, aggressiveness, anxiety, suicidal thoughts, hallucinations, sleep disturbances, depressive states.

• Sense organs: pathology of accommodation, uncontrolled movements of the eyeball, decreased visual clarity.
• Gastrointestinal: diarrhea, abnormal liver function, increased appetite.
• Urinary system: enuresis, urinary retention, dysuria.
• Allergic reactions: skin rashes, itching, urticaria, in rare cases Quincke’s edema, anaphylactic shock.

Zyrtec is not recommended for patients with a history of intolerance to cetirizine, the components of the drops, or hydroxyzine or any other piperazine derivatives.

Zyrtec is contraindicated in patients with severe renal impairment (renal clearance less than 10 ml/min).

In pediatrics, Zyrtec drops are only used to treat patients over 2 years of age.

Caution is advised when prescribing cetirizine to patients who are prone to urinary retention (cetirizine dihydrochloride may increase the likelihood of urinary retention).

Caution is important when prescribing Zyrtec Drops to patients with epilepsy and other conditions in which there is a tendency to develop seizures.

During therapy with Zyrtec, skin allergy tests should not be performed (for at least 3 days after the last dose of cetirizine, false results of such tests may be noted).

Patients with chronic renal failure, as well as elderly patients with reduced renal function, should be prescribed Zyrtec with caution (such patients need dose adjustment of cetirizine).

If side effects from the central nervous system (dizziness, drowsiness) are noted during therapy with Zyrtec, it is important to refrain from driving a car for the period of therapy.

Zyrtec has not been studied in clinical trials during human pregnancy. In laboratory studies on animals, no effect of cetirizine dihydrochloride on embryonic development, pregnancy and childbirth was detected. In cases where the use of Zyrtec drops is mandatory and the expected benefits sufficiently outweigh the possible risks, the attending physician may prescribe cetirizine to pregnant women.

Cetirizine is found in breast milk, where it can reach 25-90% of serum levels. It is necessary to prescribe cetirizine to lactating women with extreme caution.

Theophylline, when used concomitantly with Zyrtec, slightly reduces the clearance of cetirizine.

With prolonged use of ritonavir, an increase in the exposure time of cetirizine and some change in the pharmacokinetics of ritonavir may occur.

An interaction of sedatives with cetirizine has not been proven, but this combination should be avoided.

With intoxication with cetirizine, symptoms may appear that are associated with the effect of the drug on the central nervous system, as well as with the anticholinergic effect of the drops.

Overdose has generally been reported with doses 5 or more times the recommended dose. In case of overdose, patients may experience: confusion, stool disorders, mydriasis, dizziness, anxiety, fatigue, stupor, headache, asthenia, sedation, tremor, tachycardia, and urinary retention. In case of an overdose, the risk of allergic reactions, including itching, increases significantly.

There is no specific antidote for cetirizine dihydrochloride.

In case of overdose, supportive and symptomatic therapy is indicated. If no more than 20 minutes have passed since the overdose was taken, gastric lavage is performed and sorbent preparations are recommended.

There is no decrease in serum levels of cetirizine during dialysis.

10 ml Zyrtec oral drops in vials with dropper and plastic cap. 1 vial is put into a pack of laminated cardboard.

Zyrtec drops are good for 5 years after release. After the bottle has been opened, it is recommended to store the drug for no more than 3 months.