Names of prescription allergy medications in the UK range from familiar antihistamines to advanced biological therapies, reflecting the wide spectrum of allergic conditions managed within the NHS. Whilst over-the-counter options suit mild symptoms, more severe or persistent allergies often require treatments that are only available on prescription. Whether you have been newly diagnosed with allergic rhinitis, chronic urticaria, or are at risk of anaphylaxis, understanding which medications exist — and how they work — can help you have more informed conversations with your GP or allergy specialist. This article covers the key prescription options, how they are used, and important safety information.

Prescription Allergy Medications Available in the UK

For many people in the UK, over-the-counter antihistamines are sufficient to manage mild allergic symptoms. However, when allergies are more severe, persistent, or complex, a GP or allergy specialist may prescribe stronger or more targeted treatments. Understanding the names of prescription allergy medications can help patients engage more confidently with their healthcare team.

Commonly prescribed allergy medications in the UK include:

• Fexofenadine (brand name Telfast) — a non-sedating antihistamine. Fexofenadine 120 mg is available as a pharmacy medicine for urticaria; higher doses and paediatric formulations are prescription-only

• Desloratadine (Neoclarityn) — another second-generation antihistamine prescribed for chronic urticaria and allergic rhinitis^[1][2]

• Montelukast (Singulair and generics) — a leukotriene receptor antagonist licensed primarily as an add-on therapy in asthma; it may also be used for the relief of seasonal allergic rhinitis symptoms in patients whose asthma is already managed with montelukast (per the UK Summary of Product Characteristics)

• Beclometasone, fluticasone, and mometasone — intranasal corticosteroid sprays prescribed for moderate-to-severe allergic rhinitis; NICE CKS recommends these as first-line treatment for this indication

• Azelastine/fluticasone combination nasal spray (Dymista) — a prescription intranasal antihistamine and corticosteroid combination for moderate-to-severe allergic rhinitis not adequately controlled by either agent alone

• Prednisolone — an oral corticosteroid used in short courses for acute severe urticaria or angio-oedema; it is not a routine treatment for anaphylaxis

• Omalizumab (Xolair) — a biological therapy prescribed by specialists for severe allergic asthma, chronic spontaneous urticaria (CSU), and severe chronic rhinosinusitis with nasal polyps (CRSwNP)

• Adrenaline auto-injectors (e.g., EpiPen, Jext) — prescribed for individuals at risk of anaphylaxis. Note: Emerade has had its UK supply suspended since 2023 and is not currently available; patients previously prescribed Emerade should have been switched to an alternative device

• Allergen immunotherapy (subcutaneous or sublingual) — prescribed by allergy specialists to desensitise patients to specific allergens such as grass pollen, house dust mite, wasp venom, or bee venom^[5]

This range reflects the breadth of allergic conditions managed within the NHS, from seasonal hay fever to life-threatening anaphylaxis. Prescriptions are typically initiated following a clinical assessment and, where appropriate, allergy testing.

How These Medicines Work and What They Treat

Prescription allergy medications work through several distinct mechanisms, each targeting a different part of the immune or inflammatory response. Understanding how these drugs function helps clarify why different conditions require different treatments.

Antihistamines such as fexofenadine and desloratadine work by blocking H1 histamine receptors, preventing histamine — a chemical released during allergic reactions — from binding to tissues and triggering symptoms such as itching, sneezing, and urticaria. Second-generation antihistamines are preferred because they cause less sedation than older agents such as chlorphenamine.^[2]

Montelukast blocks leukotriene receptors, reducing airway inflammation and nasal congestion. Its primary licensed indication in the UK is as an add-on therapy in asthma, in line with NICE NG80. Its use for allergic rhinitis is limited to the relief of seasonal allergic rhinitis symptoms in patients whose asthma is already being managed with montelukast; it is not a first-line treatment for rhinitis in its own right.

Intranasal corticosteroids such as fluticasone and mometasone reduce local inflammation in the nasal passages by suppressing the release of inflammatory mediators. NICE CKS and the ARIA guideline recommend them as first-line treatment for moderate-to-severe allergic rhinitis, as they are more effective than oral antihistamines alone for nasal symptoms.

Omalizumab is a monoclonal antibody that binds to immunoglobulin E (IgE), a key antibody involved in allergic responses. By reducing free IgE levels, it prevents mast cell activation. It is reserved for patients with severe, inadequately controlled conditions: specifically, severe allergic asthma (dosed according to baseline IgE and body weight), CSU that has not responded adequately to high-dose H1-antihistamines, and CRSwNP in adults.

Allergen immunotherapy works by gradually desensitising the immune system to a specific allergen. For selected allergens — such as grass pollen, house dust mite, and insect venoms — delivered by trained specialists, it can be disease-modifying, inducing longer-term tolerance beyond the treatment period. This distinguishes it from symptomatic treatments, though it is not suitable for all patients or all allergens. BSACI and ARIA guidelines provide further detail on patient selection and delivery.

Dosage, Administration, and Important Safety Information

Dosage and administration vary considerably depending on the medication, the patient's age, weight, and the severity of their condition. It is essential that patients follow the prescribing clinician's instructions and the guidance provided in the patient information leaflet.

Antihistamines such as fexofenadine are typically taken once or twice daily by mouth. Apple, orange, and grapefruit juices can significantly reduce the absorption of fexofenadine (via inhibition of OATP transporters) and should be avoided for at least two hours before and after each dose; water is recommended instead. Aluminium- or magnesium-containing antacids should also be separated from fexofenadine doses by at least two hours. Desloratadine is usually taken once daily and does not carry the same juice interaction.^[1]

Montelukast is taken once daily. For patients with asthma, the SmPC recommends taking it in the evening; for allergic rhinitis, timing is more flexible. Patients and carers should be aware that the MHRA issued a safety warning in 2019 advising that montelukast may cause neuropsychiatric side effects, including sleep disturbances, anxiety, depression, and, in rare cases, suicidal thoughts. If any mood or behavioural changes occur, montelukast should be stopped and medical advice sought promptly. Montelukast is available in tablet, chewable tablet, and granule formulations for different age groups.

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Intranasal corticosteroids are administered as a nasal spray, usually once or twice daily. The spray should be primed before first use. Correct technique is important: tilt the head slightly forward, direct the spray away from the nasal septum, and sniff gently. Patients should be aware that maximal benefit may take several days of regular use to become apparent.

Omalizumab is given as a subcutaneous injection every two to four weeks. Following initial doses, administration may take place in a clinical setting with observation as per local protocol. After appropriate training, some patients or caregivers may administer subsequent doses at home, in line with the UK SmPC; this should be agreed with the supervising specialist.

1. Adrenaline auto-injectors must be carried at all times by individuals prescribed them. Two devices should be carried simultaneously. Patients and carers should receive training on correct administration technique and practise regularly using a trainer device. In an emergency:
2. Use the auto-injector at the first signs of anaphylaxis — do not delay
3. Call 999 immediately
4. Lie flat with legs raised (or sit upright if breathing is difficult; do not stand)
5. If there is no improvement after five minutes, administer the second auto-injector
6. Go to hospital by ambulance even if symptoms improve — further monitoring is always required

Check the expiry date of your devices regularly and replace them before they expire.

Possible Side Effects and Reporting Adverse Reactions

As with all prescription medicines, allergy medications carry a risk of side effects. These vary by drug class and individual patient factors. Awareness of potential adverse effects supports safe and informed use.

Second-generation antihistamines are generally well tolerated. Common side effects include headache, dry mouth, and, less commonly, mild drowsiness. Although they are considered non-sedating, patients should exercise caution when driving or operating machinery, particularly when first starting treatment.

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Montelukast has been associated with neuropsychiatric reactions, including:

• Nightmares and sleep disturbances

• Irritability, aggression, and restlessness

• Anxiety and depression

• In rare cases, suicidal thoughts

The MHRA updated its guidance in 2019 to strengthen warnings about these risks. Prescribers are advised to discuss these potential effects with patients before initiating treatment. If any mood or behavioural changes develop, montelukast should be stopped and medical advice sought promptly.

Intranasal corticosteroids are associated with local side effects such as nasal dryness, irritation, and epistaxis (nosebleeds). Systemic absorption is low at recommended doses. However, children using intranasal corticosteroids long-term or at higher doses should have their growth monitored, and the lowest effective dose should be used, in line with SmPC guidance for these medicines.

Oral corticosteroids such as prednisolone, when used long-term, carry risks including weight gain, osteoporosis, adrenal suppression, and increased susceptibility to infection. They are therefore reserved for short courses in acute situations such as severe urticaria or angio-oedema.

Omalizumab may cause injection-site reactions and, rarely, anaphylaxis. It should only be prescribed by specialists experienced in managing severe allergic disease, in line with EMA and MHRA-approved licensed indications.

Reporting suspected side effects: If you or your child experiences a suspected side effect from any prescription allergy medication, this can be reported directly to the MHRA via the Yellow Card scheme at https://yellowcard.^[3][4]mhra.gov.uk. Reporting helps the MHRA monitor the safety of medicines in real-world use.

When to Speak to Your GP or Allergy Specialist

Knowing when to seek medical advice is an important aspect of managing allergic conditions safely. Whilst many people manage their allergies effectively with prescribed treatments, certain symptoms or circumstances warrant prompt review.

Contact your GP if:

• Your current allergy medication is no longer controlling your symptoms adequately

• You experience new or worsening side effects — particularly mood or behavioural changes if taking montelukast; stop the medicine and seek advice promptly

• You develop frequent nosebleeds or nasal discomfort whilst using an intranasal corticosteroid

• You are pregnant, planning to become pregnant, or breastfeeding, as some allergy medications require careful review during these periods

• Your child's symptoms are affecting sleep, school performance, or quality of life

For urgent advice that is not a life-threatening emergency, NHS 111 is available 24 hours a day.

Call 999 immediately if:

• You or someone else shows signs of anaphylaxis, including throat swelling, difficulty breathing, a sudden drop in blood pressure, or loss of consciousness

• Use an adrenaline auto-injector straight away, call 999, lie flat with legs raised (or sit upright if breathing is difficult), and give a second dose after five minutes if there is no improvement

• A hospital assessment is always required after use of an adrenaline auto-injector, even if symptoms appear to resolve

Referral to an NHS allergy specialist may be appropriate if:

• The diagnosis is uncertain and allergy testing is needed

• Symptoms are severe or poorly controlled despite standard treatments

• Allergen immunotherapy is being considered

• There is a history of anaphylaxis requiring ongoing risk management and a written emergency action plan

NICE guidance (including CG134 on anaphylaxis) supports a structured approach to allergy management, including provision of clear written action plans for patients at risk of severe reactions. If you are unsure whether your current treatment is appropriate, a review with your GP is always a reasonable first step. Open communication with your healthcare team ensures that the most suitable prescription allergy medication is identified for your individual needs.

Frequently Asked Questions