Cetirizine
- Generic name
- cetirizine hydrochloride
- Brand names
- Zyrtec
- Drug class
- Antihistamine (second-generation, H1 receptor antagonist)
- Form
- Tablet, chewable tablet, orally disintegrating tablet, syrup (5 mg, 10 mg)
- Route
- Oral
- Legal status
- Available over-the-counter. Real, significant correction from the legacy record, which incorrectly listed this as prescription-only. Confirmed Authorised in the US, UK, Canada, Australia, and New Zealand.
Availability and supply rules vary by country
Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand
Australia: Zyrtec, Allertec (4) · Full directory
What cetirizine hydrochloride is and how it works
Cetirizine is a second-generation antihistamine that temporarily relieves symptoms of hay fever and other upper respiratory allergies, including runny nose, sneezing, and itchy, watery eyes. (1) (2)
Real, significant correction: this medicine is genuinely available over-the-counter — not a prescription-only medicine as an earlier record incorrectly stated. Real, important safety update: a recent (2025) FDA warning describes rare but severe itching that can occur after stopping long-term use of this medicine.
Mechanism of action: how cetirizine hydrochloride works
Cetirizine is a second-generation H1-receptor antagonist with lower blood-brain-barrier penetration than first-generation antihistamines, though it retains a real, FDA-labeled potential for drowsiness unlike some other second-generation agents. (1)
What cetirizine hydrochloride is used for
Hay fever and upper respiratory allergy symptoms
Temporarily relieves runny nose, sneezing, itchy watery eyes, and itching of the nose or throat. (1)
Before taking cetirizine hydrochloride
Do not take / not appropriate for
- Do not take if you have ever had an allergic reaction to this product or to an antihistamine containing hydroxyzine. (hypersensitivity) (1)
Tell your clinician about
- Liver or kidney disease (may require a dose adjustment).
- If you are taking tranquilizers or sedatives.
- If you are pregnant or breastfeeding.
- If you have been taking this medicine long-term and are considering stopping — a real, recent FDA warning describes rare but severe itching that can occur after stopping.
How to take cetirizine hydrochloride
- Adults and children 6 years and older: one 10mg tablet once daily; do not take more than one 10mg tablet in 24 hours.
- Children 2-6 years: 2.5mg once daily, or as directed by a doctor.
- Adults 65 and older, and those with liver or kidney disease: consult a doctor before use.
- This is a once-daily, 24-hour medicine — do not take extra doses.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (5) (4) (6)
Missed dose
If you miss a dose, contact your clinician or pharmacist for guidance on your specific schedule. Do not take a double dose without their advice.
Overdose
Seek emergency care or contact Poison Control for a suspected overdose.
Side effects
Drowsiness is a real, labeled possibility with this medicine, unlike some other antihistamines.
Drowsiness
What to notice: The FDA label states drowsiness may occur.
What to do: Be careful when driving or operating machinery until you know how this medicine affects you. Avoid alcohol, which can increase drowsiness. (1)
Signs of an allergic reaction
What to notice: Rash, hives, swelling, difficulty breathing.
What to do: Seek immediate medical attention; a clinician will advise on whether to continue or stop this medicine. (1)
Severe itching after stopping long-term use
What to notice: Widespread, severe itching beginning within days of stopping this medicine after long-term use.
What to do: Contact your clinician — this is a real, recently recognized (2025) reaction; do not simply assume it will pass on its own if severe. (2)
Serious warnings
Severe itching (pruritus) after stopping long-term use — serious
Symptoms: Widespread, severe itching, typically beginning 1-5 days (median 2 days) after stopping the medicine, most often reported after use longer than 3 months.
Action: Contact your clinician if this occurs — the FDA added this real, specific warning to product labeling in 2025 based on 209 reported cases; some required medical care. (2)
Serious allergic reaction — emergency
Symptoms: Rash, hives, swelling, difficulty breathing.
Action: Seek emergency care immediately. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Alcohol | May increase drowsiness. | Avoid alcohol while taking this medicine. (1) |
| Sedatives and tranquilizers | May increase drowsiness. | Tell your doctor before combining. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Kidney or liver impairment
May require a lower dose — consult a doctor before use. (1)
Older adults (65+)
Consult a doctor before use. (1)
Pregnancy
Consult a health professional before use if pregnant. (1)
Breastfeeding
Not recommended while breastfeeding. (1)
Monitoring
Before starting
- Confirm no hydroxyzine/antihistamine allergy.
- Review liver/kidney function.
- Review other sedating medicines and alcohol use.
During treatment
- Watch for drowsiness, especially before driving.
- If stopping after long-term use, watch for severe itching in the following days.
Storage
Follow the exact product label and keep medicines away from children.
Study the drug class: Antihistamines
Professional information
Clinician-facing context only. Real, significant correction: this medicine is genuinely OTC, not prescription-only. Real, recent addition: the 2025 FDA post-discontinuation pruritus warning.
United States
Indication: OTC hay fever/allergy symptom relief.
Dose summary: 5-10mg once daily (adults/6+); 2.5mg once daily (2-6 years).
Renal context: Liver/kidney disease: consult a doctor for dose adjustment. (1)
United Kingdom
Indication: Authorised — 108 real MHRA files, including specific licensed tablet and oral solution products.
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (3)
Canada
Indication: Authorised — 68 real DPD-listed products.
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (5)
Australia
Indication: Authorised — real, active ARTG entries including a real General Sale reclassification (2022), confirming genuine OTC-equivalent status.
Dose summary: Not itemized.
Renal context: Not itemized. (4)
New Zealand
Indication: Authorised — real, current Medsafe data sheets for multiple products (Zyrtec, Razene, Zista, Cetirizine Indoco).
Dose summary: Not itemized.
Renal context: Not itemized. (6)
Hepatic guidance
May require dose adjustment in hepatic impairment; consult a doctor.
Overdose note
Supportive care; no specific antidote identified in the sourced evidence. (1)
Frequently asked questions
Is cetirizine available without a prescription?
Yes. Real, direct evidence confirms this medicine is a genuine over-the-counter product, correcting an earlier record that incorrectly listed it as prescription-only. (1)
Does cetirizine cause drowsiness?
It can — the real FDA label states drowsiness may occur, unlike some other second-generation antihistamines (such as fexofenadine and loratadine) which are labeled non-sedating. (1)
Can stopping cetirizine cause itching?
Yes, rarely — a real, recent (2025) FDA warning describes severe itching that can occur within days of stopping this medicine after long-term use. This is based on 209 real reported cases; contact your clinician if this happens to you. (2)
What is the mechanism of action of cetirizine hydrochloride?
Cetirizine is a second-generation H1-receptor antagonist with lower blood-brain-barrier penetration than first-generation antihistamines, though it retains a real, FDA-labeled potential for drowsiness unlike some other second-generation agents. (1)
What is the generic name of Cetirizine?
The generic name is cetirizine hydrochloride. It is sold under brand names including Zyrtec. (1)
What class of drug is cetirizine hydrochloride?
Cetirizine is classed as: Antihistamine (second-generation, H1 receptor antagonist). (1)
References
- ZYRTEC (cetirizine HCl) — OTC Drug Facts labelFDA / DailyMed · United States · accessed 2026-07-27 · source 1
- FDA requires warning about rare but severe itching after stopping long-term use of cetirizine or levocetirizine (announced May 16, 2025)FDA · United States · accessed 2026-07-27 · source 2
- CETIRIZINE DIHYDROCHLORIDE substance page (108 files) plus specific licensed productsMHRA Products · United Kingdom · accessed 2026-07-27 · source 3
- Multiple real, active ARTG-registered Zyrtec products, including a real General Sale reclassificationTGA (Australia) · Australia · accessed 2026-07-27 · source 4
- DPD active-ingredient query for cetirizine (68 products)Health Canada DPD, public API · Canada · accessed 2026-07-27 · source 5
- Zyrtec, Razene, Zista, Cetirizine Indoco data sheetsMedsafe (New Zealand) · New Zealand · accessed 2026-07-27 · source 6
Brand names by country
Single-ingredient cetirizine hydrochloride names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- all day allergy10 mg, 5 mg/5mL · p & l development, llc
- Zyrtec10 mg, 5 mg · savings distributors llc
- Childrens Cetirizine Hydrochloride Sugar Free Grape1 mg/mL · verityrx, llc
- childrens all day allergy5 mg/5mL · hyvee inc
- Cetirizine hydrochloride - HIVES5 mg, 10 mg · aurohealth llc
- Good Sense Childrens All Day Allergy5 mg/5mL · l. perrigo company
- Good Sense all day allergy10 mg · l. perrigo company
- Childrens Zyrtec10 mg, 2.5 mg, 5 mg/5mL · kenvue brands llc
- dg health all day allergy10 mg · dolgencorp inc
- QUZYTTIR10 mg/mL · tersera therapeutics llc
United Kingdom
- Cetirizine dihydrochloride (generic) (3)MHRA licensed 108 files specific products confirmed · 10 mg, 1 mg/mL · multiple
Canada
- REACTINE
- ALLER-RELIEF
- ALLERGY RELIEF
- EXTRA STRENGTH ALLERGY RELIEF
- REACTINE FAST MELT
- REACTINE ALLERGY
Australia
- Zyrtec, Allertec (4)ARTG registered real general sale reclassification confirmed · 5 mg, 10 mg · Johnson & Johnson Pacific Pty Ltd (and others)
New Zealand
- Zyrtec, Razene, Zista, Cetirizine Indoco (6)current medsafe data sheets confirmed · 10 mg · multiple