Telfast

How to order Telfast

1. Find the drug you need on our site.
2. Pick a clinic. See the price.
3. Fill in a short health form.
4. A doctor reads your form.
5. If it is safe for you, they say yes.
6. Your order ships fast to your door.
7. It comes in a plain, sealed box.

Why use us? We compare UK clinics. We show you the price and how fast they ship. We do not sell drugs. We just help you find the best one for you.

Is it safe? Yes. All our clinics are UK-based. A real doctor reads each form. They will not sell to you if it is not safe for you.

Telfast on Prescriptsy

Telfast is described on Prescriptsy as independent product information.

Here you can understand how online consultation works, what medical checks partner clinics carry out, and which factors matter when comparing providers.

We do not sell medicines directly, but help users compare licensed healthcare partners on price, delivery speed, service quality, and overall trustworthiness.

Telfast is a brand of fexofenadine hydrochloride, a non-sedating (second-generation) antihistamine used to relieve the symptoms of seasonal allergic rhinitis (hayfever) and chronic idiopathic urticaria (hives of unknown cause).

Fexofenadine is the active metabolite of terfenadine and was developed to provide effective antihistamine activity without the cardiac safety concerns that led to terfenadine's withdrawal.

Telfast is available in two strengths: 120 mg for hayfever and 180 mg for chronic urticaria, both taken once daily.

It is a prescription-only medicine (POM) in the United Kingdom.

Allergic rhinitis is one of the most common chronic conditions in the UK, affecting approximately 10 to 30 million people.

Seasonal allergic rhinitis (hayfever) is triggered primarily by grass pollen (the dominant allergen in the UK), tree pollen, and weed pollen.

Symptoms include sneezing, nasal congestion, rhinorrhoea (runny nose), nasal itching, and ocular symptoms (itchy, watery, red eyes).

Although often perceived as trivial, hayfever significantly impairs quality of life, sleep quality, concentration, work productivity, and school performance.

Chronic idiopathic urticaria affects approximately 0.5% to 1% of the population and presents as recurrent itchy wheals (hives) lasting more than 6 weeks, with no identifiable external trigger.

This page provides a comprehensive clinical guide to Telfast, covering how it works, dosage instructions, side effects, safety warnings, and how to obtain a prescription in the United Kingdom.

Important safety information about Telfast

Before reading further, please note these essential safety points.

• Telfast is a non-sedating antihistamine that does not usually cause drowsiness, making it suitable for people who need to drive or operate machinery.
• Do not take Telfast with orange, apple, or grapefruit juice, as these reduce absorption. Take with plain water.
• Telfast is not suitable for treating severe allergic reactions (anaphylaxis). If you experience swelling of the face, lips, or throat, or difficulty breathing, call 999 immediately.
• Telfast 120 mg and 180 mg are licensed for adults and adolescents aged 12 and over. A separate lower-dose product is available for younger children.
• If hayfever symptoms are not adequately controlled, discuss additional treatments with your prescriber.

Understanding allergic rhinitis

Allergic rhinitis occurs when the immune system overreacts to inhaled allergens, producing an IgE-mediated hypersensitivity response.

On first exposure to an allergen (sensitisation), B lymphocytes produce allergen-specific immunoglobulin E (IgE) antibodies, which bind to the surface of mast cells in the nasal mucosa.

On subsequent exposure, the allergen cross-links IgE molecules on the mast cell surface, triggering degranulation and the release of preformed mediators (histamine, tryptase) and newly synthesised mediators (prostaglandins, leukotrienes, cytokines).

Histamine is the primary mediator of the immediate allergic response.

It binds to H1 receptors on sensory nerve endings (causing sneezing and itching), blood vessels (causing vasodilation, increased permeability, and nasal congestion), and mucous glands (causing rhinorrhoea).

A late-phase response occurs 4 to 12 hours later, driven by the influx of eosinophils, basophils, and T lymphocytes, which perpetuate the inflammatory process and contribute to nasal congestion and hyperreactivity.

In the UK, the pollen season typically begins in late March with tree pollens (birch, ash, oak), peaks from May to July with grass pollen (the most common trigger), and extends into August and September with weed pollens (mugwort, nettle).

The Met Office and the National Pollen Monitoring Network provide daily pollen forecasts to help sufferers plan their activities.

Understanding chronic idiopathic urticaria

Chronic idiopathic urticaria (also called chronic spontaneous urticaria) is defined as the occurrence of itchy wheals (hives) on most days for more than 6 weeks, without an identifiable external trigger.

The wheals are caused by activation of mast cells in the dermis, releasing histamine and other mediators that cause localised vasodilation, increased vascular permeability, and sensory nerve stimulation.

Individual wheals typically last less than 24 hours and resolve without bruising.

Angioedema (deeper swelling, often affecting the lips, eyelids, or hands) accompanies the wheals in approximately 40% of cases.

The cause of chronic spontaneous urticaria remains unknown in the majority of cases, hence the term "idiopathic." Current evidence suggests an autoimmune basis in many patients, with autoantibodies directed against IgE or the high-affinity IgE receptor (FcepsilonRI) on mast cells.

The NICE guideline on urticaria and the British Association of Dermatologists (BAD) guideline recommend second-generation (non-sedating) antihistamines as first-line treatment, with up-dosing (up to four times the standard licensed dose) considered if the standard dose is insufficient, under specialist supervision.

How Telfast works

Fexofenadine hydrochloride is a selective, peripheral H1-receptor antagonist.

It competitively and reversibly blocks histamine binding at H1 receptors on target tissues, preventing the cascade of symptoms triggered by histamine release.

Unlike first-generation antihistamines (chlorphenamine, promethazine, hydroxyzine), fexofenadine has minimal ability to cross the blood-brain barrier due to its physicochemical properties (it is a zwitterion with low lipophilicity) and active efflux by P-glycoprotein at the blood-brain barrier.

This results in negligible occupation of central H1 receptors and explains its non-sedating profile.

Fexofenadine also lacks affinity for muscarinic acetylcholine receptors, alpha-adrenergic receptors, and serotonin receptors, meaning it does not cause the anticholinergic side effects (dry mouth, blurred vision, urinary retention, constipation) or the sedative effects associated with first-generation antihistamines.

Beyond simple H1 receptor blockade, fexofenadine has additional anti-allergic properties.

In vitro studies have demonstrated inhibition of histamine release from mast cells, suppression of eosinophil migration, and reduction of inflammatory cytokine and adhesion molecule expression.

These properties may contribute to its clinical efficacy, particularly in chronic urticaria.

Telfast compared with other antihistamines

Several second-generation antihistamines are available in the UK, including cetirizine (Zirtek), loratadine (Clarityn), desloratadine (Neoclarityn), bilastine (Ilaxten), and fexofenadine (Telfast).

All are effective for allergic rhinitis and urticaria, but they differ in their sedative potential and pharmacokinetic profiles.

Cetirizine causes mild drowsiness in approximately 5% to 10% of users and is classified as "less sedating" rather than truly "non-sedating." Loratadine and desloratadine have low sedation rates similar to fexofenadine.

Bilastine is a newer non-sedating antihistamine with a similar profile to fexofenadine.

Fexofenadine is generally considered the least sedating of all available antihistamines based on objective psychomotor testing data.

The European Medicines Agency and the British Society for Allergy and Clinical Immunology (BSACI) recognise fexofenadine as non-sedating.

This makes it a particularly suitable choice for people who drive, operate machinery, or whose work requires sustained concentration.

First-generation antihistamines (chlorphenamine, promethazine) are effective but cause significant sedation, impaired psychomotor performance, and anticholinergic effects.

They should generally be reserved for situations where sedation is desirable (such as acute allergic reactions or insomnia due to itching) and should not be used for long-term management of chronic allergic conditions.

Clinical evidence for fexofenadine

The efficacy of fexofenadine in seasonal allergic rhinitis has been demonstrated in multiple large, randomised, double-blind, placebo-controlled trials.

Fexofenadine 120 mg once daily significantly reduced total symptom scores (a composite of sneezing, rhinorrhoea, nasal congestion, and itchy/watery eyes) compared with placebo, with onset of action within 1 to 3 hours of the first dose and sustained 24-hour efficacy with regular daily dosing.

Head-to-head trials have shown comparable efficacy to cetirizine 10 mg, with significantly less sedation as measured by standardised psychomotor testing.

In chronic idiopathic urticaria, fexofenadine 180 mg once daily has been shown to significantly reduce pruritus severity, number of wheals, and overall disease activity compared with placebo in randomised controlled trials.

The duration of efficacy supports once-daily dosing for this indication.

The pollen calendar and hayfever management

Understanding the UK pollen calendar helps hayfever sufferers anticipate their symptoms and optimise treatment timing.

Tree pollen season runs from late February to May, with birch pollen being the most allergenic tree pollen in the UK.

Grass pollen season runs from mid-May to mid-August, peaking in June and July. Weed pollen (mugwort, nettle, dock) is present from June to September.

Fungal spores peak in late summer and autumn. Most hayfever sufferers in the UK are allergic to grass pollen.

Starting antihistamine treatment at the beginning of the relevant pollen season, before symptoms become established, may provide better symptom control than waiting until symptoms are severe. This is known as "pre-seasonal" or "prophylactic" antihistamine use.

Dosage and administration

For hayfever, take one Telfast 120 mg tablet once daily with water. For chronic urticaria, take one Telfast 180 mg tablet once daily with water.

Take before a meal if possible, though this is not essential. Avoid taking within 1 to 2 hours of fruit juice (orange, apple, grapefruit).

Continue daily use throughout the symptomatic period.

Side effects of Telfast

Common side effects

Headache is the most commonly reported side effect (5% to 7%), though rates in clinical trials were similar to placebo. Drowsiness occurs in 1% to 3% of users, comparable to placebo. Nausea and dizziness are uncommon.

Cardiac safety

Fexofenadine does not prolong the QT interval at therapeutic or supratherapeutic doses and does not share the cardiac risk associated with its parent compound terfenadine.

This has been confirmed in thorough QT studies. Fexofenadine can be taken safely with CYP3A4 inhibitors (erythromycin, ketoconazole) without risk of cardiac arrhythmias, unlike terfenadine.

When to seek medical advice

Telfast is not suitable for treating anaphylaxis or severe allergic reactions.

If you experience sudden swelling of the face, lips, tongue, or throat, difficulty breathing, or feeling faint after exposure to an allergen, call 999 immediately.

This is a medical emergency requiring intramuscular adrenaline.

Contact your GP or call NHS 111 if your hayfever or urticaria symptoms are not adequately controlled, if you develop new symptoms, or if you are unsure whether your symptoms are due to allergy.

Report suspected adverse reactions to the MHRA at yellowcard.mhra.gov.uk .

Warnings and precautions

Fruit juice interaction

Fexofenadine absorption is reduced by approximately 30% to 40% when taken with orange, apple, or grapefruit juice.

This is due to inhibition of organic anion-transporting polypeptides (OATPs) in the intestinal wall by flavonoids in the juice.

Take Telfast with plain water and avoid fruit juice within 1 to 2 hours of dosing.

Renal impairment

Approximately 11% of fexofenadine is excreted renally. In patients with reduced kidney function, plasma concentrations may be higher than in patients with normal renal function. A lower dose or less frequent dosing may be appropriate; consult your prescriber.

Pregnancy and breastfeeding

Data on the use of fexofenadine during pregnancy are limited. Animal studies have not shown teratogenic effects.

Discuss with your prescriber before using Telfast if you are pregnant or planning pregnancy.

Loratadine and cetirizine are often preferred during pregnancy as they have more established human safety data.

Fexofenadine has been detected in breast milk in animal studies; caution is advised during breastfeeding.

Children

Telfast 120 mg and 180 mg tablets are not licensed for children under 12 years of age.

For children aged 6 to 11, fexofenadine 30 mg twice daily is the licensed dose, available as a separate product.

Fexofenadine is not recommended for children under 6 years of age.

Comprehensive hayfever management

Antihistamines are one component of comprehensive hayfever management.

Additional measures include allergen avoidance (staying indoors when pollen counts are high, keeping windows closed, wearing sunglasses, showering and changing clothes after outdoor exposure), intranasal corticosteroid sprays (fluticasone propionate, mometasone furoate, beclometasone dipropionate), antihistamine or mast cell stabiliser eye drops (sodium cromoglicate, olopatadine, azelastine), and nasal saline irrigation.

For severe or refractory hayfever, allergen immunotherapy (subcutaneous or sublingual) may be considered under specialist care.

NICE technology appraisal TA312 supports the use of sublingual grass pollen immunotherapy for moderate-to-severe hayfever not controlled by standard pharmacotherapy.

How to get Telfast in the UK

Telfast is available on NHS prescription from your GP or an authorised online prescriber registered with the General Pharmaceutical Council (GPhC).

The standard NHS prescription charge in England is 9.90 pounds per item; prescriptions are free in Scotland, Wales, and Northern Ireland.

Generic fexofenadine is also available and is often less expensive. Some lower-strength fexofenadine products may be available as pharmacy medicines from your pharmacist without a prescription.

Sources

• Telfast 120 mg, Summary of Product Characteristics (EMC)
• Fexofenadine hydrochloride, British National Formulary (BNF)
• Allergic rhinitis, NICE CKS
• Urticaria, NICE CKS
• Hay fever, NHS
• MHRA Yellow Card Scheme