Fexofenadine
Also known as: Telfast, Allevia
Fexofenadine is a non-drowsy antihistamine that relieves allergy symptoms such as those of hay fever and hives by blocking the effects of histamine. Some people still feel sleepy or dizzy, and the NHS advises against driving, cycling or using tools or machinery if that happens. Swelling of the face, lips, tongue or throat with difficulty breathing can be a sign of a serious allergic reaction, and the leaflets say to tell a doctor immediately.
- Generic name
- Fexofenadine
- Active ingredient
- Fexofenadine (variants: fexofenadine hydrochloride)
- Product type
- Small-molecule medicine
- Drug class
- Antihistamines
- Brand names
- UK Telfast, Allevia, Almerg, Histallay, Treathay · US
- Routes
- Oral
- Dosage forms
- Tablet
- Also known as
- Telfast, Allevia
- Usual preparations
- Film-coated tablets; tablets for children under 12 are available on prescription (summary of the cited reference, not a prescription)
- Onset and duration
- The NHS says relief usually starts within 1 to 2 hours.
- Monitoring
- The NHS says fexofenadine is unlikely to cause harm when taken for a long time, though it is best taken only for as long as it is needed.
Availability by country
| Country | Status | Note | Source |
|---|---|---|---|
| UK | Over the counter | 120 mg tablets for people aged 12 and over are sold in pharmacies and supermarkets | UK |
| UK | Prescription only | Tablets for children under 12 are prescription-only | UK |
Legal status differs between countries and can change; each row cites the document it was taken from and applies only to the country named.
What it is used for
- Allergy symptoms such as a runny nose, sneezing, and red, itchy or watery eyes, including hay fever
- Hives, with their itching and redness
- Conjunctivitis, eczema, insect bite and sting reactions and some food allergies, which the NHS lists among its uses
How it works in the body
Fexofenadine blocks the effects of histamine, a substance in the body that drives allergy symptoms. A 2024 clinical review describes it as a non-sedating, second-generation H1 antihistamine. The NHS says it seems less likely to cause sleepiness than other non-drowsy antihistamines.
Common side effects
- Headache, feeling sleepy, feeling sick and feeling dizzy are the common side effects the NHS lists.
- Although fexofenadine is classed as non-drowsy, some people feel quite sleepy, and the NHS advises not driving, cycling or using tools or machinery while sleepy or dizzy.
Serious: seek help
- Swelling of the face, lips, tongue or throat with difficulty breathing can signal a serious allergic reaction; leaflets say to stop the medicine and tell a doctor immediately, and in an emergency the route is 999.
Cautions and interactions
- Grapefruit, orange and apple juice can reduce how well fexofenadine works, and MedlinePlus advises taking it with water rather than fruit juice.
- Leaflets say that indigestion remedies containing aluminium and magnesium can lower how much fexofenadine is absorbed, and advise leaving a gap between the two.
- A leaflet states that apalutamide, a prostate cancer medicine, may decrease the effect of fexofenadine.
- The NHS says it is best not to drink alcohol while taking fexofenadine, as it can make you feel sleepy.
- The NHS lists liver or kidney problems and heart problems among the reasons fexofenadine may not be suitable, and leaflets advise talking to a doctor or pharmacist first about liver or kidney problems, heart disease or older age.
- One leaflet says antihistamines such as fexofenadine may cause a fast or irregular heartbeat.
- The NHS lists having ever had an allergic reaction to fexofenadine or any other medicine among the reasons it may not be suitable.
- The NHS lists pregnancy, trying to get pregnant and breastfeeding among the situations where fexofenadine may not be suitable, and UK leaflets advise against use in pregnancy unless necessary and say it is not recommended while breastfeeding.
- The NHS says anyone due an allergy test should check first, because the medicine can affect the results.
- The NHS says fexofenadine does not affect any type of contraception, including the combined pill and emergency contraception.
Interactions
Check interactions
Taking Fexofenadine with other medicines? Add them to the checker to see what the official sources say about each pair: the mechanism, general management and monitoring, never a bare "safe".
Interactions documented in the official sources cited on each card. The list covers the medicines represented on this site and is not exhaustive; how the interaction data is compiled.
No pair records for this medicine are in the sources currently represented by Anatomy Nexus. Absence from this list does not mean no interaction exists.
Same-class and related medicines
Same class: Antihistamines
Medicines that share the class of Fexofenadine. They are separate medicines with their own licences, doses and interactions, not alternative names for Fexofenadine.
Related medicines
Medicines often discussed alongside Fexofenadine: used together, compared with it, or acting on the same problem by a different route.
Key facts
| Fact | Detail |
|---|---|
| Brand names (UK) | Telfast, Allevia, Almerg, Histallay, Treathay |
| Type | Non-drowsy (second-generation) antihistamine |
| UK availability | tablets over the counter for adults and children aged 12 and over; tablets for younger children on prescription |
| Starts to work | Within 1 to 2 hours, according to the NHS |
| Common side effects | Headache, sleepiness, feeling sick, dizziness |
| Take care with | Grapefruit, orange and apple juice; alcohol; indigestion remedies containing aluminium and magnesium |
| Serious allergic reaction | Face, lip, tongue or throat swelling with difficulty breathing: tell a doctor immediately, per the leaflets |
What is fexofenadine used for?
Fexofenadine is an antihistamine medicine that relieves the symptoms of allergies. The NHS lists hay fever, conjunctivitis, eczema, hives, insect bite and sting reactions and some food allergies among the problems it is used for. MedlinePlus describes it as treating allergy symptoms such as a runny nose, sneezing, and red, itchy or watery eyes, as well as itching and redness caused by hives.
The NHS says tablets for treating hives are available from pharmacies. MedlinePlus has a separate page for products that combine fexofenadine with pseudoephedrine, which are different products from fexofenadine on its own.
How does fexofenadine work?
Fexofenadine blocks histamine, a substance in the body that drives allergy symptoms. The NHS says that by blocking the effects of histamine it reduces the symptoms, and that people should start to feel better within 1 to 2 hours. A 2024 clinical review describes it as a non-sedating, second-generation H1 antihistamine.
The NHS classes fexofenadine as non-drowsy and says it seems less likely to cause sleepiness than other non-drowsy antihistamines. It also says fexofenadine is unlikely to cause harm when used for a long time, though it is best taken only for as long as it is needed.
What are the side effects of fexofenadine?
The NHS lists headaches, feeling sleepy, feeling sick and feeling dizzy as the common side effects. Fexofenadine is classed as a non-drowsy antihistamine, but some people still feel quite sleepy. The NHS advises not driving, cycling or using tools or machinery while feeling sleepy or dizzy. Leaflets say fexofenadine is unlikely to affect the ability to drive or use machinery, but advise checking first that the tablets do not cause sleepiness or dizziness.
Swelling of the face, lips, tongue or throat with difficulty breathing can be a sign of a serious allergic reaction. The leaflets say to stop the medicine and tell a doctor immediately. In an emergency, call 999.
Fexofenadine with food, drink and other medicines
The NHS says grapefruit, orange and apple juice can reduce how well fexofenadine works. MedlinePlus likewise advises taking it with water rather than with fruit juices such as orange, grapefruit or apple juice. The NHS also says it is best not to drink alcohol while taking fexofenadine, as it can make you feel sleepy.
Leaflets say that indigestion remedies containing aluminium and magnesium can lower how much fexofenadine is absorbed, and advise leaving a gap between the two. A leaflet states that apalutamide, a prostate cancer medicine, may decrease the effect of fexofenadine. The NHS says fexofenadine does not affect any type of contraception, including the combined pill and emergency contraception.
Who can take fexofenadine, and who needs extra care?
The NHS says tablets for adults and children aged 12 and over can be bought from pharmacies and supermarkets, while tablets for children under 12 are only available on prescription from a doctor. The NHS lists liver or kidney problems and heart problems among the reasons fexofenadine may not be suitable, and leaflets advise talking to a doctor or pharmacist first about liver or kidney problems, heart disease or older age. One leaflet says antihistamines such as fexofenadine may cause a fast or irregular heartbeat.
The NHS lists pregnancy, trying to get pregnant and breastfeeding among the situations where fexofenadine may not be suitable. UK leaflets advise against use in pregnancy unless necessary and say it is not recommended while breastfeeding. The NHS also says anyone due an allergy test should check first, because the medicine can affect the results. The NHS lists having ever had an allergic reaction to fexofenadine or any other medicine among the reasons it may not be suitable. Leaflets differ in wording between products, so the leaflet that comes with a particular product applies to it.
Frequently asked questions
Is fexofenadine a non-drowsy antihistamine?
The NHS classes fexofenadine as non-drowsy and says it seems less likely to cause sleepiness than other non-drowsy antihistamines. Even so, some people feel quite sleepy or dizzy, and the NHS advises not driving, cycling or using tools or machinery if that happens.
Can fruit juice be drunk with fexofenadine?
The NHS says grapefruit, orange and apple juice can reduce how well fexofenadine works. MedlinePlus advises taking it with water rather than fruit juice. The NHS also says it is best not to drink alcohol while taking fexofenadine.
How quickly does fexofenadine work?
The NHS says people should start to feel better within 1 to 2 hours. It says fexofenadine is unlikely to cause harm when used for a long time, but it is best taken only for as long as it is needed.
Can fexofenadine be bought without a prescription?
The NHS says tablets for adults and children aged 12 and over can be bought from pharmacies and supermarkets. Tablets for children under 12 are only available with a prescription from a doctor.
Does fexofenadine affect contraception?
The NHS says fexofenadine does not affect any type of contraception, including the combined pill and emergency contraception.
Can fexofenadine be used in pregnancy or while breastfeeding?
The NHS lists pregnancy, trying to get pregnant and breastfeeding among the situations where fexofenadine may not be suitable. UK leaflets advise against use in pregnancy unless necessary and say it is not recommended while breastfeeding. A GP or pharmacist can advise on an individual situation.
Connected pages in detail
What each linked page on Anatomy Nexus covers, in a line, for Fexofenadine.
Symptoms
- Rash Any change in the colour or texture of the skin.
Medications
- Cetirizine and antihistamines A second-generation (less sedating) antihistamine that blocks histamine H1 receptors to relieve hay fever, hives and other allergic symptoms.
- Chlorphenamine A first-generation antihistamine, sold over the counter, that relieves hay fever.
Drug classes
- Antihistamines Medicines that block histamine's H1 receptors to relieve hay fever, hives and itching.