Kestine (Ebastine)
Second-Generation Antihistamine for Allergic Rhinitis and Urticaria
Quick Facts About Kestine
Key Takeaways About Kestine
- Fast-acting allergy relief: Kestine starts working within 1 hour and provides 24-hour symptom control with a single daily tablet
- Low sedation profile: As a second-generation antihistamine, Kestine causes significantly less drowsiness than older antihistamines, though some people may still experience mild sedation
- Available over-the-counter: Kestine 10 mg can be purchased without a prescription for short-term relief of temporary allergic symptoms
- 14-day self-treatment limit: If symptoms persist beyond 14 days, consult a doctor to rule out a more serious underlying condition
- Not for young children: Kestine 10 mg tablets are not recommended for children under 12 years of age
What Is Kestine and What Is It Used For?
Kestine (ebastine) is a second-generation antihistamine that blocks the effects of histamine, a chemical released by the body during allergic reactions. It is used to relieve symptoms of allergic rhinitis (hay fever), allergic conjunctivitis, and itching caused by insect bites.
Kestine belongs to the second-generation (also called non-sedating) antihistamine group. Its active ingredient, ebastine, selectively blocks peripheral histamine H1 receptors. When you are exposed to allergens – such as pollen, pet dander, dust mites, or mould – your immune system releases histamine from mast cells. Histamine then binds to H1 receptors in the nose, eyes, skin, and airways, triggering the classic symptoms of an allergic reaction: sneezing, runny nose, nasal congestion, itchy and watery eyes, and skin itching.
By occupying the H1 receptors before histamine can bind to them, ebastine effectively prevents these allergic symptoms from developing. Unlike first-generation antihistamines (such as diphenhydramine or chlorphenamine), ebastine has a much lower affinity for H1 receptors in the brain, which is why it causes significantly less drowsiness and cognitive impairment. This makes Kestine suitable for use during the day when you need to remain alert.
Kestine is clinically indicated for the following allergic conditions:
- Allergic rhinitis (hay fever): Seasonal or perennial rhinitis caused by pollen, pet dander, dust mites, or mould, presenting with sneezing, runny nose, nasal congestion, and itching of the nose and palate
- Allergic conjunctivitis: Red, watery, itchy eyes that occur alongside or independently of nasal symptoms during exposure to airborne allergens
- Insect bite hypersensitivity: Itching and localised urticarial reactions (hives) caused by mosquito or other insect bites in people who are particularly sensitive to insect venom or saliva
After oral administration, ebastine is rapidly absorbed from the gastrointestinal tract and extensively metabolised in the liver by the cytochrome P450 enzyme CYP3A4 to its pharmacologically active metabolite, carebastine. Carebastine is responsible for the therapeutic antihistamine effect. Peak plasma concentrations of carebastine are reached approximately 2.6 to 4 hours after dosing. The elimination half-life of carebastine is 15 to 19 hours, which supports the convenient once-daily dosing schedule. The onset of action occurs within approximately 1 hour of taking the tablet, and the antihistamine effect persists for a full 24 hours.
Ebastine was first developed by the Spanish pharmaceutical company Almirall and has been marketed since the 1990s. It is approved in numerous countries across Europe, Asia, and Latin America. The active metabolite carebastine has also been developed as a separate drug (desloratadine is a related but distinct molecule). Ebastine is included in the class of second-generation antihistamines recommended by the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines as first-line pharmacotherapy for allergic rhinitis.
What Should You Know Before Taking Kestine?
Before taking Kestine, inform your doctor or pharmacist if you have severe liver disease, are taking antifungal or antibiotic medications, or are pregnant or breastfeeding. Kestine should not be taken if you are allergic to ebastine or any of the tablet's excipients.
Contraindications
You should not take Kestine if:
- You are allergic to ebastine or any of the other ingredients in the tablet (listed in the composition section below). Signs of an allergic reaction may include itching, rash, swelling of the face or throat, or difficulty breathing
If you have experienced a hypersensitivity reaction to ebastine in the past, you should avoid all products containing this active ingredient, regardless of the brand name. Alternative antihistamines such as cetirizine, loratadine, or fexofenadine may be considered instead.
Warnings and Precautions
Talk to your doctor or pharmacist before taking Kestine if any of the following apply to you:
- Severely impaired liver function: Ebastine is extensively metabolised by the liver. If you have significant hepatic impairment (such as cirrhosis or chronic liver disease), the metabolism of ebastine may be altered, leading to higher plasma concentrations of the drug and its metabolites. Your doctor should assess whether Kestine is appropriate and may advise a reduced dose (no more than 10 mg daily)
- Known cardiac arrhythmias or QT prolongation: Although ebastine at recommended doses has not been shown to cause clinically significant QT prolongation, high doses (particularly when combined with CYP3A4 inhibitors) may theoretically increase this risk. If you have a pre-existing heart rhythm disorder, discuss this with your doctor before starting Kestine
- Lactose intolerance: Kestine film-coated tablets contain lactose monohydrate as an excipient. If you have been diagnosed with an intolerance to certain sugars, consult your doctor before taking this medicine
Kestine may cause dry mouth in some users. If you are using Kestine for extended periods (beyond the 14-day OTC limit, under medical supervision), it is important to maintain good oral hygiene. Brush your teeth with fluoride toothpaste at least twice daily, as chronic dry mouth can increase the risk of dental caries (tooth decay). Sugar-free lozenges or sips of water can help alleviate dry mouth symptoms.
Kestine tablets contain less than 1 mmol (23 mg) of sodium per tablet, making them essentially sodium-free. They do contain lactose monohydrate. If you have lactose intolerance, speak to your pharmacist about whether the amount of lactose in the tablet is likely to cause you problems, or consider an alternative antihistamine formulation.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, are planning to become pregnant, or are breastfeeding, seek advice from your doctor or pharmacist before taking Kestine.
Pregnancy: There is limited clinical data on the use of ebastine during pregnancy. Animal reproduction studies have not demonstrated direct harmful effects on the foetus, but human data are insufficient to fully establish safety. As a precaution, it is generally recommended to avoid Kestine during pregnancy unless the expected benefit clearly outweighs any potential risk. Your healthcare provider may recommend better-studied alternatives such as cetirizine or loratadine, which have more extensive safety data in pregnancy.
Breastfeeding: It is not known whether ebastine or its active metabolite carebastine is excreted in human breast milk. A risk to the nursing infant cannot be excluded. If you are breastfeeding, consult your doctor before using Kestine. They will weigh the benefit of allergy treatment for you against any potential risk to your baby.
Driving and Operating Machinery
Although Kestine is classified as a non-sedating antihistamine, some individuals may experience drowsiness, dizziness, or impaired concentration while taking it. These effects are generally mild and occur more frequently at the start of treatment. You are responsible for assessing whether you are fit to drive or operate machinery. If you notice any impairment in your alertness, do not drive or use machines until the effects have fully resolved. Consult your doctor if these symptoms persist.
How Does Kestine Interact with Other Drugs?
Kestine (ebastine) is metabolised by the liver enzyme CYP3A4. Drugs that inhibit this enzyme – including certain antifungals and antibiotics – can increase ebastine levels in the blood. Drugs that induce CYP3A4, such as rifampicin, can decrease its effectiveness. Always inform your doctor or pharmacist about all medications you are taking.
Ebastine is a prodrug that is converted to its active metabolite carebastine primarily by the CYP3A4 enzyme system in the liver. Drugs that significantly inhibit or induce CYP3A4 can alter the blood levels of ebastine and carebastine, potentially affecting both efficacy and safety. Clinical pharmacokinetic interaction studies have identified the following important interactions.
Clinically Significant Interactions
| Drug | Category | Effect | Recommendation |
|---|---|---|---|
| Ketoconazole | Antifungal (azole) | Potent CYP3A4 inhibitor that significantly increases ebastine and carebastine plasma levels | Avoid combination or use under medical supervision with ECG monitoring |
| Itraconazole | Antifungal (azole) | Strong CYP3A4 inhibitor that raises ebastine levels, potentially increasing risk of QT prolongation at high concentrations | Avoid combination or use under medical supervision |
| Erythromycin | Macrolide antibiotic | Moderate CYP3A4 inhibitor that increases ebastine blood levels | Use with caution; consult your doctor if concurrent use is necessary |
| Rifampicin | Antibiotic (tuberculosis treatment) | Potent CYP3A4 inducer that significantly decreases ebastine and carebastine levels, reducing antihistamine efficacy | Kestine may be less effective; an alternative antihistamine or higher dose may be needed under medical guidance |
Other Considerations
While ebastine has a relatively favourable interaction profile compared to some other medications, a few additional points are worth noting:
- Other CYP3A4 inhibitors: Drugs such as clarithromycin, voriconazole, ritonavir, and grapefruit juice can also inhibit CYP3A4 and may increase ebastine levels. If you take any of these, inform your healthcare provider
- Alcohol: Although studies have not demonstrated a significant pharmacokinetic interaction between ebastine and alcohol, both substances can independently cause sedation. As a precaution, it is advisable to limit alcohol consumption while taking Kestine
- Other antihistamines: Taking Kestine together with other antihistamines is generally unnecessary and may increase the risk of side effects, particularly drowsiness. Do not combine antihistamines unless specifically directed to do so by your doctor
- Central nervous system depressants: Benzodiazepines, opioids, and other CNS depressants may have additive sedative effects when taken with antihistamines. Consult your doctor if you are taking any of these medications
If you are unsure whether any of your current medications might interact with Kestine, consult your pharmacist before starting treatment. This is particularly important if you take regular prescription medications or have multiple medical conditions.
What Is the Correct Dosage of Kestine?
The recommended dose for adults and adolescents aged 12 years and over is one 10 mg tablet once daily, taken in the morning with breakfast. Treatment should not exceed 14 days without medical advice. In cases of severe symptoms, the dose may be increased to two tablets (20 mg) daily under medical supervision.
Always use Kestine exactly as described in the product information leaflet or as directed by your doctor or pharmacist. If you are unsure about anything, ask your pharmacist for guidance before taking the medicine.
Adults and Adolescents (12 Years and Over)
Standard Dose for Allergic Rhinitis and Conjunctivitis
Dose: 1 tablet (10 mg) once daily
Timing: Take in the morning with breakfast
Duration: Up to 14 days for self-treatment (OTC use)
The onset of action is approximately 1 hour after taking the tablet, and the antihistamine effect lasts for a full 24 hours. This allows convenient once-daily dosing. Taking the tablet with food does not significantly affect absorption but may improve tolerability.
Severe Symptoms (Under Medical Supervision Only)
Dose: 2 tablets (20 mg) once daily
If your allergy symptoms are particularly severe and the standard 10 mg dose does not provide adequate relief, your doctor may recommend increasing the dose to 20 mg daily. Do not increase the dose on your own – this should only be done under medical guidance. The 20 mg dose has been studied in clinical trials and shown to be effective for more severe allergic symptoms while maintaining an acceptable safety profile.
Children
Under 12 Years
Not recommended: Kestine 10 mg tablets should not be given to children under 12 years of age.
For children who require antihistamine treatment, consult your doctor or pharmacist about suitable alternatives that are formulated for younger age groups, such as cetirizine oral solution (available for children from 2 years of age) or loratadine syrup.
Special Populations
Patients with severely impaired liver function: If you have significant liver disease, you should not exceed 1 tablet (10 mg) per day. Your doctor should assess whether Kestine is appropriate for you. The liver is responsible for metabolising ebastine to its active form, and impaired liver function can alter drug levels.
Elderly patients: No specific dose adjustment is generally required for elderly patients. However, elderly individuals may be more susceptible to the sedative effects of antihistamines. Start with the standard 10 mg dose and monitor for any adverse effects.
Patients with kidney impairment: Ebastine and carebastine are primarily eliminated by the liver. No dose adjustment is needed for patients with renal impairment.
Practical Tips for Taking Kestine
- Pet allergy: If you are allergic to cats, dogs, or other pets, take Kestine approximately 1 hour before visiting a home where pets are present. This allows the antihistamine to reach therapeutic levels before allergen exposure
- Insect bite prevention: For relief from mosquito bite itching, Kestine works best when taken before being bitten. The anti-itch effect on mosquito bites lasts less than 2 hours after the bite occurs, so preventive dosing is far more effective. People who are especially sensitive to mosquito bites benefit most from this approach
- Pollen season: During hay fever season, take Kestine consistently every morning for the duration of the pollen exposure period. Consistent daily dosing maintains steady blood levels of the active metabolite
Missed Dose
If you forget to take your Kestine tablet, simply skip the missed dose and take your next dose at the usual time the following day. Do not take a double dose to make up for the one you missed. Because ebastine has a relatively long duration of action, missing a single dose is unlikely to result in a complete loss of symptom control.
Overdose
If you have taken more Kestine than recommended, or if a child has accidentally swallowed tablets, contact your doctor, hospital emergency department, or poison control centre immediately for assessment and advice. Symptoms of antihistamine overdose may include drowsiness, dry mouth, headache, rapid heartbeat, and in severe cases, cardiac arrhythmias. Seek medical attention promptly even if you feel well, as some effects may be delayed.
What Are the Side Effects of Kestine?
The most common side effects of Kestine are headache, drowsiness, and dry mouth. Most side effects are mild and resolve on their own. Seek immediate medical attention if you experience signs of a severe allergic reaction such as difficulty breathing, facial swelling, or itchy rash.
Like all medicines, Kestine can cause side effects, although not everybody gets them. The following side effects have been reported in clinical trials and post-marketing surveillance. They are grouped by frequency according to international conventions.
- Itching, itchy rash (urticaria), difficulty swallowing, or shortness of breath
- Low blood pressure, feeling faint or collapsing
- Swelling of the face, tongue, or throat (angioedema)
These may be signs of a severe allergic reaction (anaphylaxis), which has been reported rarely.
Very Common
May affect more than 1 in 10 people
- Headache
Common
May affect up to 1 in 10 people
- Drowsiness (somnolence)
- Dry mouth
Rare
May affect up to 1 in 1,000 people
- Nervousness, insomnia
- Dizziness, decreased sensation (hypoaesthesia), taste disturbances
- Palpitations, abnormal heart rhythm
- Abdominal pain, nausea, vomiting, indigestion
- Liver enzyme elevations, abnormal liver function tests
- Urticaria (hives), skin rash, dermatitis
- Menstrual irregularities
- Fluid retention (oedema)
- Fatigue
Frequency Not Known
Cannot be estimated from available data
- Weight gain
- Increased appetite
Most side effects of Kestine are mild and transient. Headache and drowsiness tend to diminish with continued use as the body adjusts to the medication. Dry mouth can be managed with regular sips of water, sugar-free gum, or saliva substitutes. If any side effect becomes severe or you notice effects not listed here, contact your doctor or pharmacist.
Reporting Side Effects
Reporting suspected side effects after a medicine has been authorised is important. It allows ongoing monitoring of the medicine's benefit-risk balance. Healthcare professionals and patients are encouraged to report any suspected adverse reactions to their national pharmacovigilance authority. In the United Kingdom, reports can be submitted to the MHRA via the Yellow Card Scheme. In the European Union, reports should be submitted through the national competent authority in each member state.
How Should You Store Kestine?
Store Kestine at a temperature not exceeding 30°C in the original outer carton to protect from light. Keep out of the sight and reach of children. Do not use after the expiry date.
Proper storage of medications is important to ensure they remain effective and safe. Follow these guidelines for storing Kestine:
- Temperature: Store at a maximum of 30°C (86°F). Do not refrigerate or freeze
- Light protection: Keep the tablets in the original outer carton, as ebastine is light-sensitive
- Children: Store all medicines out of the sight and reach of children. Consider storing medications in a locked medicine cabinet if there are young children in the household
- Expiry date: Do not use Kestine after the expiry date stated on the packaging (marked “EXP”). The expiry date refers to the last day of the stated month
- Disposal: Do not dispose of unused medicines via household waste or down the drain. Return unused tablets to your pharmacy for safe disposal. This helps protect the environment
What Does Kestine Contain?
Each Kestine film-coated tablet contains 10 mg of the active ingredient ebastine. The tablets are round, white, scored, and marked with “E10”. They are available in packs of 10 and 30 tablets.
Active Ingredient
Each film-coated tablet contains 10 mg ebastine. Ebastine is a piperidine derivative that acts as a selective, second-generation H1 histamine receptor antagonist. It has a molecular weight of 469.66 g/mol and is practically insoluble in water. Following oral absorption, it is rapidly converted to its active metabolite carebastine by hepatic CYP3A4 enzymes.
Excipients (Inactive Ingredients)
The film-coated tablets contain the following inactive ingredients:
- Microcrystalline cellulose – a bulking and binding agent
- Lactose monohydrate – a filler (important for people with lactose intolerance)
- Pregelatinised maize starch – a disintegrant to help the tablet break apart
- Croscarmellose sodium – a super-disintegrant for rapid tablet dissolution
- Magnesium stearate – a lubricant used during tablet manufacture
- Hypromellose (hydroxypropyl methylcellulose) – a film-coating agent
- Polyethylene glycol 6000 (macrogol) – a plasticiser for the film coating
- Titanium dioxide (E171) – a white colouring agent for the film coating
Appearance and Pack Sizes
Kestine 10 mg film-coated tablets are round, white, biconvex tablets with a score line (break line) and embossed with “E10” on one side. The score line allows the tablet to be divided for easier swallowing but is not intended for dose splitting. The tablets are available in blister packs of 10 or 30 tablets. Not all pack sizes may be marketed in all countries.
Marketing Authorisation Holder and Manufacturer
Kestine is manufactured by Industrias Farmacéuticas Almirall, S.A. in Barcelona, Spain. The marketing authorisation is held by Almirall S.A., Ronda General Mitre 151, 08022 Barcelona, Spain. Local distribution is handled by Almirall ApS in various European countries.
Frequently Asked Questions About Kestine
Kestine (ebastine) is a second-generation antihistamine used to relieve symptoms of allergic rhinitis (hay fever) such as sneezing, runny nose, nasal congestion, and itchy, watery, red eyes (allergic conjunctivitis). It is also effective for relieving itching and hives caused by insect bites in people who are particularly sensitive. Kestine works by blocking the H1 histamine receptors, preventing the allergic symptoms triggered by histamine release.
Kestine is classified as a second-generation (non-sedating) antihistamine, which means it is significantly less likely to cause drowsiness compared to older antihistamines such as diphenhydramine or chlorphenamine. However, drowsiness is still listed as a common side effect that may affect up to 1 in 10 people. Individual sensitivity varies, and some people may experience mild sedation. If you notice drowsiness, avoid driving or operating machinery until the effect has passed.
Kestine begins to work within approximately 1 hour of taking a dose. The antihistamine effect lasts for a full 24 hours, allowing for convenient once-daily dosing. For people with pet allergies, it is advisable to take Kestine about 1 hour before expected allergen exposure. For mosquito bite itch relief, the medication is most effective when taken preventively before being bitten, as the anti-itch effect on bites lasts less than 2 hours.
There is limited data on the safety of Kestine (ebastine) during pregnancy and breastfeeding. It is not known whether ebastine passes into breast milk. As a precaution, you should consult your doctor or pharmacist before taking Kestine if you are pregnant, think you may be pregnant, are planning a pregnancy, or are breastfeeding. Your healthcare provider can advise on whether Kestine is appropriate or recommend an alternative antihistamine with a better-established safety profile in pregnancy, such as cetirizine or loratadine.
Kestine is intended for short-term self-treatment of temporary allergic symptoms for a maximum of 14 days. If your symptoms persist beyond this period, you should consult a doctor to investigate whether there is a more serious underlying cause for your symptoms and to determine whether longer-term treatment is appropriate. For seasonal allergies such as hay fever, your doctor may advise extended use under medical supervision for the duration of the pollen season.
Kestine 10 mg tablets should not be given to children under 12 years of age. For adolescents aged 12 years and over, the recommended dose is the same as for adults: 1 tablet (10 mg) once daily. If your child is younger than 12 and requires an antihistamine, consult your doctor or pharmacist about alternatives that are specifically formulated for younger children, such as cetirizine drops or loratadine oral solution.
References
This article is based on the following peer-reviewed sources, international guidelines, and regulatory references:
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- Zuberbier T, Abdul Latiff AH, Abuzakouk M, et al. The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy. 2022;77(3):734–766. doi:10.1111/all.15090
- World Health Organization (WHO). Model List of Essential Medicines – 23rd List, 2023. Geneva: WHO; 2023.
- British National Formulary (BNF). Antihistamines, non-sedating. NICE. Available at: bnf.nice.org.uk. Accessed January 2026.
Editorial Team
This article has been written and reviewed by iMedic's medical editorial team, which includes licensed physicians specialising in allergy, immunology, and clinical pharmacology.
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