Allergies medication for adults covers a broad range of treatments, from everyday antihistamines to prescription-only immunotherapy. In the UK, allergic conditions such as hay fever, urticaria, and allergic rhinitis affect millions of adults, yet many are unsure which medication is most appropriate for their symptoms or how to access it safely. This guide explains the main types of allergy medication available to adults in the UK, how they work, how to choose between them, and when to seek further medical advice — drawing on current NHS, NICE, MHRA, and BSACI guidance to help you make informed decisions about your care.

Common Types of Allergy Medication Available for Adults in the UK

Managing allergies effectively in adults typically involves one or more categories of medication, each targeting different aspects of the allergic response. In the UK, the most widely used options include antihistamines, corticosteroids, decongestants, mast cell stabilisers, leukotriene receptor antagonists, and immunotherapy. These are available through a combination of NHS prescriptions and pharmacies, including internet pharmacies registered with the General Pharmaceutical Council (GPhC) and displaying the GPhC internet pharmacy logo — the recognised way to verify a legitimate UK online pharmacy.

The most commonly encountered allergy medications for adults include:

• Antihistamines (e.g., cetirizine, loratadine, fexofenadine) — used for hay fever, urticaria, and mild allergic reactions

• Intranasal corticosteroids (e.g., beclometasone, fluticasone propionate, mometasone) — first-line treatment for allergic rhinitis according to NICE CKS guidance

• Topical corticosteroids (e.g., hydrocortisone cream) — for allergic skin conditions such as eczema or contact dermatitis

• Decongestants (e.g., pseudoephedrine, xylometazoline) — for nasal congestion associated with allergic rhinitis; for short-term use only

• Mast cell stabilisers (e.g., sodium cromoglicate eye drops) — particularly useful for allergic conjunctivitis

• Leukotriene receptor antagonists (e.g., montelukast) — occasionally used under GP or specialist supervision for selected adults with allergic rhinitis, though not a first-line option; important safety considerations apply (see below)

• Adrenaline auto-injectors (e.g., EpiPen, Jext) — prescribed for adults at risk of anaphylaxis

For longer-term management of specific allergies, allergen immunotherapy (desensitisation) may be considered under specialist supervision. This involves gradually exposing the immune system to increasing amounts of an allergen, either via subcutaneous injections (SCIT) or sublingual tablets or drops (SLIT). Immunotherapy is disease-modifying and typically requires a course of around three years. It carries a risk of systemic allergic reactions and must be initiated and monitored by a specialist with appropriate facilities. NICE has approved sublingual immunotherapy for severe grass pollen allergy in adults where standard treatments have proved insufficient (see, for example, NICE technology appraisals on grass pollen sublingual immunotherapy products). BSACI guidelines provide further detail on patient selection and monitoring.

How Antihistamines, Steroids and Other Treatments Work

Understanding the mechanism behind allergy medications helps explain why different treatments are suited to different symptoms and conditions. Allergic reactions occur when the immune system mistakenly identifies a harmless substance — such as pollen, dust mites, or pet dander — as a threat, triggering the release of histamine and other inflammatory mediators from mast cells and basophils.

Antihistamines work by competitively blocking H1 histamine receptors, thereby preventing histamine from binding and causing symptoms such as itching, sneezing, and watery eyes. Second-generation antihistamines (e.g., cetirizine, loratadine, fexofenadine) are preferred over first-generation options (e.g., chlorphenamine) because they are less sedating and have a longer duration of action, making them more suitable for daily use. It is worth noting that sedation varies even within second-generation antihistamines: fexofenadine is generally the least sedating, whilst cetirizine may still cause mild drowsiness in some individuals.

Corticosteroids act more broadly by suppressing the inflammatory cascade at a cellular level. Intranasal corticosteroids reduce mucosal inflammation in the nasal passages and are particularly effective for persistent allergic rhinitis. They primarily relieve nasal symptoms; ocular symptoms may only be modestly improved and may require separate treatment with antihistamine or mast cell stabiliser eye drops. Intranasal corticosteroids typically take several days to reach full effect, so consistent daily use is important. Topical steroids applied to the skin reduce localised inflammation in conditions such as allergic contact dermatitis.

Decongestants work by causing vasoconstriction in the nasal mucosa, reducing swelling and congestion. Topical nasal decongestants (e.g., xylometazoline nasal spray) should not be used for more than five to seven days continuously due to the risk of rebound congestion (rhinitis medicamentosa). Oral decongestants (e.g., pseudoephedrine) should also be used for the shortest time necessary and only as directed in the patient information leaflet (PIL) or by a pharmacist or GP.

Mast cell stabilisers prevent the degranulation of mast cells, thereby reducing the release of histamine before it occurs — making them most effective when used prophylactically, before allergen exposure.

Each mechanism complements the others, which is why combination therapy is often recommended for moderate-to-severe allergies. Your pharmacist or GP can advise on the most appropriate combination for your symptoms.

Choosing the Right Allergy Medication for Your Symptoms

Selecting the most appropriate allergy medication depends on the nature, severity, and pattern of your symptoms, as well as any underlying health conditions or other medications you may be taking. NICE CKS recommends a stepwise approach to managing common allergic conditions such as allergic rhinitis and urticaria.

For hay fever and allergic rhinitis, NICE CKS recommends intranasal corticosteroids as the first-line treatment for adults with moderate-to-severe or persistent symptoms, as they are the most effective single treatment for nasal symptoms. A non-sedating oral antihistamine may be added if nasal symptoms remain inadequately controlled. If ocular symptoms are prominent, antihistamine or sodium cromoglicate eye drops may be needed in addition, as intranasal corticosteroids provide only modest benefit for eye symptoms. For mild or intermittent symptoms, a non-sedating antihistamine taken as needed is often sufficient.

For allergic skin conditions such as urticaria (hives), non-sedating antihistamines are the mainstay of treatment. If symptoms are not adequately controlled at a standard dose, NICE CKS and BSACI guidance supports increasing the dose of a non-sedating antihistamine up to four times the standard dose (off-label use) before considering a short course of oral corticosteroids. Repeated or prolonged courses of oral corticosteroids should be avoided. Adults with chronic urticaria (symptoms lasting more than six weeks) should be referred to a GP or specialist for further assessment.

For allergic conjunctivitis, sodium cromoglicate eye drops are available over the counter and are commonly recommended. Antihistamine eye drops are also effective; some preparations (e.g., azelastine) are prescription-only, whilst others may be available OTC — a pharmacist can advise on the most suitable option.

When choosing between medications, consider the following:

• Symptom type: nasal, ocular, skin, or systemic

• Frequency: intermittent vs persistent symptoms

• Lifestyle factors: sedating antihistamines may impair driving or operating machinery; avoid alcohol when taking sedating antihistamines

• Comorbidities: some decongestants are unsuitable for adults with hypertension, cardiovascular disease, hyperthyroidism, glaucoma, or benign prostatic hyperplasia

• Pregnancy or breastfeeding: always consult a pharmacist or GP before starting any allergy medication

A community pharmacist can provide valuable guidance on over-the-counter options and help identify when a GP referral is warranted.

Prescription vs Over-the-Counter Options on the NHS

In the UK, a wide range of allergy medications are available both over the counter (OTC) at pharmacies and on NHS prescription, though access and cost considerations differ between the two routes. Understanding these distinctions can help adults make informed decisions about their care.

Many commonly used antihistamines — including cetirizine and loratadine — are available to purchase OTC without a prescription. Fexofenadine is available OTC at certain strengths and for specific indications (for example, 120 mg tablets for hay fever); however, the 180 mg strength remains prescription-only (POM) — a pharmacist can advise on which product is appropriate for you. Similarly, some intranasal corticosteroid nasal sprays can be bought at pharmacies, including beclometasone dipropionate 50 micrograms/spray, fluticasone propionate 50 micrograms/spray, and mometasone furoate 50 micrograms/spray (the latter for adults aged 18 and over). This means that for many adults with mild-to-moderate allergic rhinitis or hay fever, effective treatment is accessible without a GP appointment.

However, it is important to note that NHS England guidance advises GPs not to routinely prescribe OTC medications for minor conditions, including mild hay fever, where self-care is appropriate. This means that adults who can manage their symptoms with pharmacy-bought products may be directed to do so rather than receiving an NHS prescription. Prescription-only medications — such as higher-dose nasal corticosteroids, montelukast (a leukotriene receptor antagonist sometimes used for allergic rhinitis under specialist or GP supervision), or adrenaline auto-injectors — require a GP or specialist consultation.

Montelukast is not a first-line treatment for allergic rhinitis. The MHRA has issued a safety warning regarding the risk of neuropsychiatric reactions with montelukast (including agitation, sleep disturbances, depression, and, rarely, suicidal thoughts). Anyone prescribed montelukast should be made aware of these risks and should seek prompt medical advice if such symptoms occur.

For adults who pay for NHS prescriptions, a Prescription Prepayment Certificate (PPC) can reduce costs significantly if multiple medications are required. Those who are exempt from prescription charges — including individuals with certain medical conditions or those receiving qualifying benefits — may find it more cost-effective to obtain medications on prescription. NHS community pharmacists can advise on the most appropriate and cost-effective route for individual circumstances.

Possible Side Effects and Safety Considerations for Adults

As with all medications, allergy treatments carry a risk of side effects, and adults should be aware of these before starting any new treatment. The safety profile varies considerably between drug classes, and individual factors such as age, comorbidities, and concurrent medications can influence tolerability.

Antihistamines are generally well tolerated, but first-generation options (e.g., chlorphenamine) can cause significant drowsiness, dry mouth, urinary retention, and blurred vision due to their anticholinergic properties. These effects are particularly relevant for older adults, in whom anticholinergic burden is associated with an increased risk of falls and cognitive impairment. Second-generation antihistamines are far less sedating, though cetirizine may still cause mild drowsiness in some individuals. Sedating antihistamines can impair the ability to drive or operate machinery, and their effects are increased by alcohol and other CNS depressants.

Intranasal corticosteroids, when used at recommended doses, have low systemic absorption and are considered safe for long-term use. Localised side effects can include nasal dryness, epistaxis (nosebleeds), and, rarely, nasal septal perforation with prolonged use. Adults should be advised to direct the spray away from the nasal septum.

Oral corticosteroids, if used repeatedly or for extended periods, carry risks including adrenal suppression, osteoporosis, weight gain, and elevated blood glucose — making them unsuitable for long-term allergy management.

Decongestants should be used with caution in adults with hypertension or cardiovascular disease, hyperthyroidism, glaucoma, or benign prostatic hyperplasia. The MHRA has issued updated safety advice regarding pseudoephedrine: there is a risk of serious but rare conditions including posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS). Pseudoephedrine should be avoided in adults with severe or uncontrolled hypertension or severe renal impairment. If you experience a sudden severe headache, visual disturbance, confusion, or other neurological symptoms whilst taking pseudoephedrine, stop the medication and seek urgent medical attention. The MHRA also advises that pseudoephedrine-containing products should not be used in children under 12.

Montelukast carries an MHRA warning regarding neuropsychiatric reactions, including agitation, nightmares, depression, and, rarely, suicidal thoughts. If you or someone you care for experiences any of these symptoms whilst taking montelukast, stop the medication and seek prompt medical advice.

Drug interactions are an important consideration — for example, some antihistamines may interact with CNS depressants or certain antidepressants. Always inform your pharmacist or GP of all medications you are currently taking, and read the patient information leaflet (PIL) supplied with your medication carefully.

If you experience a suspected side effect from any allergy medication, you can report it to the MHRA via the Yellow Card scheme at yellowcard.mhra.gov.uk. Your report helps improve the safety of medicines for everyone.

When to Seek Further Medical Advice for Allergies

Whilst many adults can manage mild-to-moderate allergies effectively with OTC medications and self-care, there are circumstances in which it is important to seek further medical advice from a GP or specialist. Recognising these situations promptly can prevent complications and ensure appropriate investigation and treatment.

You should contact your GP if:

• Your allergy symptoms are not adequately controlled despite using appropriate OTC treatments for two to four weeks

• Symptoms are significantly affecting your quality of life, sleep, or ability to work

• You develop new or worsening symptoms that are difficult to attribute to a known allergen

• You experience side effects from your current allergy medication

• You are pregnant, breastfeeding, or have a significant comorbidity such as asthma, cardiovascular disease, or renal impairment

• You have previously experienced anaphylaxis or a severe allergic reaction

• You have symptoms suggestive of a food allergy with systemic features

• You have chronic urticaria or angioedema lasting more than six weeks

• Your rhinitis remains poorly controlled despite optimised treatment and good adherence, or you wish to discuss immunotherapy

• You have co-existing asthma that is poorly controlled alongside allergic symptoms

You should seek emergency medical attention (call 999 or go to A&E) immediately if you experience signs of anaphylaxis, which include:

• Sudden onset of throat tightening, difficulty breathing, or stridor

• Swelling of the lips, tongue, or throat

• Rapid or weak pulse, dizziness, or collapse

• Widespread urticaria combined with systemic symptoms

Adults who have previously experienced anaphylaxis should be under the care of an allergy specialist and should carry two adrenaline auto-injectors at all times, as recommended by NICE and the British Society for Allergy and Clinical Immunology (BSACI). Ensure you and those around you know how to use your auto-injector, and ask your GP or specialist about a written allergy action plan.

For adults with persistent or complex allergies, a GP may refer to an NHS allergy clinic for formal allergy testing (skin prick testing or specific IgE blood tests) and consideration of immunotherapy. Specialist input may help improve long-term symptom control and reduce reliance on daily medication, in line with BSACI and NICE guidance.

Frequently Asked Questions