Request ConsultationCetirizine is a second-generation antihistamine that is used to treat symptoms caused by allergic reactions. Cetirizine acts by inhibiting the actions of histamine, which is a natural substance produced by the body during allergic reactions. Some of the common uses of cetirizine include seasonal allergies, perennial allergies, and chronic hives. Cetirizine is found in both prescription and over-the-counter medications and is generally taken once a day. While cetirizine is said to be less sedating than some of the first-generation antihistamines, it may still cause drowsiness in some individuals. Cetirizine comes with a significant FDA warning regarding itching caused by discontinuing its use.
Important Warnings while taking Cetirizine
The use of cetirizine can result in drowsiness or fatigue, and patients need to assess their reactions to the drug before driving or operating machinery. Moreover, patients should discuss the interaction of the drug with alcohol, sedatives, sleep-inducing medications, or other central nervous system depressants, as these may intensify drowsiness.
Patients using the drug for an extended period of time should also be informed about the FDA’s 2025 warning regarding severe itching after discontinuing the drug. According to the FDA’s findings, there have been 209 reports of severe itching caused by cetirizine, levocetirizine, or both. The adverse reaction typically occurred shortly after the discontinuation of prolonged daily therapy with these drugs. Patients experiencing such symptoms need to inform their healthcare provider.
Patients with liver and kidney diseases should consider getting medical approval before using cetirizine since certain organ dysfunction may affect metabolism and excretion of the drug. People who are allergic to cetirizine, hydroxyzine, or any component of the drug product should not use it. Women who are pregnant or lactating should consult their healthcare provider before using cetirizine.
Things to consider before Cetirizine consumption
- Allergies
- Kidney or liver disease
- Age
- Pregnancy and breastfeeding
- Drowsiness and alcohol use
- Other medicines
- Long-term daily use
- Existing medical conditions
- Sedative
- Alcohol use
- Older adults
It is essential to consider all the above factors as the effects of cetirizine may vary based on one’s health condition, age, and other medications used. Those individuals who have problems with the kidneys or liver need to consult a healthcare professional regarding the suitable dosage. Older patients may experience a higher sensitivity to drowsiness and other adverse reactions. Special attention needs to be paid by pregnant and lactating women.
Cetirizine may increase the side effects when combined with alcohol, tranquilizers, sleeping pills, and other substances that cause drowsiness. It is necessary to consult a healthcare provider before starting cetirizine therapy in case other prescription and OTC medicines are taken. Regular long-term use of cetirizine may result in a serious itching reaction after the drug is discontinued, according to the FDA recommendations. Cetirizine cannot be taken by patients who have an allergy to it.
Application/Consumption
It is an oral drug administered in the form of tablets, chewable tablets, capsules, and oral solution. The consumption of cetirizine depends on the product, but normally, it is consumed either with or without food. It is usually consumed once a day since it gives allergy relief for about 24 hours. When using the liquid form, the dosing should be done using the provided dosing device and not with a spoon.
For adults and children who qualify to receive OTC drug therapy, the common formulation is 10 mg. According to the FDA-approved labeling of Zyrtec, both adults and children over the age of six years are allowed to consume one 10 mg tablet each day. This will treat mild symptoms, whereas there might need to consume one 5 mg tablet of the formulation may be needed for severe symptoms. The label states not to consume more than one 10 mg tablet in a day. For individuals over 65 years old, those under the age of 6 years, and those with liver or kidney disease, a prescription from a doctor should be sought.
Cetirizine is to be taken following the directions written on the particular label or as directed by a healthcare provider. People are discouraged from taking excess amounts for quicker results.
Dosing information
The appropriate cetirizine dose depends on age, symptoms, formulation, and kidney or liver function.
For adults and children aged 6 years and older, common OTC labeling recommends 5 mg or 10 mg once daily, with a maximum of 10 mg in 24 hours for the referenced 10 mg tablet product. A 5 mg dose may be appropriate when allergy symptoms are less severe.
Patients should not increase the dose simply because symptoms remain bothersome. Persistent symptoms may require evaluation to determine whether another treatment or a different diagnosis should be considered.
Uses
Cetirizine is used for:
- Seasonal allergic rhinitis: It helps relieve sneezing, runny nose, itchy nose or throat, and itchy or watery eyes associated with seasonal allergies.
- Perennial allergic rhinitis: It can help manage allergy symptoms that occur throughout the year because of allergens such as dust mites, mold, or animal dander.
- Chronic hives: Cetirizine is used to reduce itching and other symptoms associated with chronic idiopathic urticaria.
- Allergy-related itching: Its antihistamine activity can help reduce itching associated with allergic reactions.
FDA states that cetirizine is approved for seasonal and year-round allergies and chronic hives in specified age groups.
Cetirizine side effects
The possible side effects of cetirizine include drowsiness, fatigue, headache, dry mouth, sore throat, cough, epistaxis, diarrhea, nausea and vomiting, and other mild gastrointestinal side effects. In particular, drowsiness is an essential aspect since even the newest generation of antihistamines such as cetirizine can cause a negative impact on attention in certain patients. Other drugs and alcohol consumption can enhance this effect.
Also, there are unwanted effects in patients with reduced renal function since the drug is primarily metabolized through the kidneys. In this case, the doctor's consultation for dose adjustment is needed. The elderly population should be treated with caution since sensitivity to medications and drowsiness become more pronounced with aging.
In particular, it is crucial to mention that the severe itching occurred after discontinuation of long-term daily therapy with cetirizine. Thus, the FDA identified 209 cases of pruritus after cessation of cetirizine or levocetirizine. In these cases, 180 were caused by cetirizine, 27 were caused by levocetirizine, and 2 were attributed to both drugs. The median time of the reaction was two days after the therapy stopped, and the duration of treatment ranged from one week to several years. FDA noted that the reaction appears to be rare relative to the widespread use of these medicines, and the underlying mechanism remains unknown.
Patients suffering from severe itching on discontinuation of the drug need to consult a health care practitioner. According to the FDA, most of the patients were relieved upon re-administration of the medication, while some of the patients recovered from symptoms through re-administration followed by gradual withdrawal of the drug under the supervision of a healthcare provider. It should be noted that the patient should not try to take this step by himself.
The drug can interact with substances or drugs that depress the central nervous system. Alcohol, sedatives, sleeping medicines, and other drugs can add to the risk of drowsiness. The patient should tell healthcare providers about all kinds of medicines, OTC products, and supplements used prior to regular cetirizine treatment.
Anaphylaxis due to cetirizine is rare, but it can happen. Symptoms like swelling of the face, lips, tongue, or throat, difficulty in breathing, or severe rash require immediate medical care. People who have experienced an allergic reaction to cetirizine or similar antihistamines should discuss other treatment options with a healthcare practitioner.
Key insight:
In January 2026, ESTEVE and TerSera Therapeutics LLC announced that they have entered into an agreement under which ESTEVE will acquire TerSera’s Infusion Specialty Therapies Business Unit. This strategic acquisition will strengthen ESTEVE’s presence in the U.S. through two highly specialized marketed assets and a dedicated team of sales, marketing, and medical professionals. TerSera’s IST business unit includes two specialty medications: Prialt (ziconotide intrathecal infusion) and Quzyttir (cetirizine hydrochloride injection
