Comparison of OTC allergy medications is a common concern for the millions of people in the UK managing hay fever, urticaria, or allergic conjunctivitis. With antihistamines, intranasal corticosteroid sprays, eye drops, and decongestants all available without a prescription, choosing the right product can feel overwhelming. Each medication class works differently, targets different symptoms, and carries its own safety profile. This guide explains how the main OTC allergy treatments compare, which symptoms each is best suited to, and when to seek advice from a pharmacist or GP — helping you make an informed, safe choice for effective allergy relief.

How OTC Allergy Medications Work and What They Treat

Over-the-counter (OTC) allergy medications are widely available in the UK without a prescription and are used to manage a range of allergic conditions, including allergic rhinitis (hay fever), urticaria (hives), allergic conjunctivitis, and mild skin reactions. These products work by targeting different parts of the allergic response, which is triggered when the immune system overreacts to a harmless substance such as pollen, dust mites, or pet dander.

The most common mechanism involves blocking histamine — a chemical released by mast cells during an allergic reaction. Histamine binds to H1 receptors throughout the body, causing familiar symptoms such as sneezing, itching, watery eyes, and nasal congestion. Antihistamines competitively block these receptors, reducing symptom severity. Other OTC products, such as corticosteroid nasal sprays, work by reducing local inflammation in the nasal passages, while decongestants act on adrenergic receptors to constrict blood vessels and relieve nasal congestion.

It is important to understand that OTC allergy treatments are symptomatic — they manage symptoms rather than treating the underlying allergy. They are not appropriate for managing acute allergic reactions to foods or other triggers that may cause anaphylaxis; anyone who has been prescribed an adrenaline auto-injector should carry it at all times and follow their emergency action plan.

For mild to moderate seasonal or perennial allergies, OTC treatments can be highly effective when used correctly. NICE CKS guidance on allergic rhinitis recommends a stepwise approach: a non-sedating oral antihistamine is appropriate for mild or intermittent symptoms, whilst an intranasal corticosteroid spray is the preferred first-line option for moderate-to-severe or persistent nasal symptoms. Non-pharmacological measures — such as allergen avoidance, saline nasal irrigation, and wearing wraparound sunglasses to reduce ocular pollen exposure — are also recommended alongside medication and are consistent with NHS self-care advice.

Antihistamines, Nasal Sprays and Eye Drops: Key Differences

OTC allergy medications fall into several distinct categories, each targeting different symptoms and anatomical sites. Understanding these differences is essential for effective symptom control.

Antihistamines are available as tablets, capsules, liquids, and topical creams. Oral antihistamines provide systemic relief and are particularly useful for widespread symptoms such as sneezing, itching, urticaria, and runny nose. Topical antihistamine creams (e.g., mepyramine, found in products such as Anthisan) can be applied to small, localised insect-bite reactions, but are generally not recommended for urticaria or large skin areas due to the risk of contact sensitisation; oral antihistamines are preferred for skin allergies.

Intranasal corticosteroid sprays are available OTC in the UK and are considered highly effective for nasal symptoms including congestion, sneezing, and rhinorrhoea. UK-licensed OTC examples include beclometasone dipropionate (e.g., Beconase), fluticasone propionate spray (e.g., Flixonase Allergy Relief), triamcinolone acetonide (e.g., Nasacort Allergy), and mometasone furoate (e.g., Clarinaze). They work locally within the nasal mucosa and have minimal systemic absorption at recommended doses. Importantly, they require consistent daily use for several days before maximum benefit is achieved, making them more suitable for ongoing or predictable allergy seasons rather than immediate relief. Most OTC intranasal corticosteroid sprays are licensed for adults aged 18 years and over; always check the patient information leaflet (PIL) or seek pharmacist advice before using in younger patients.

Eye drops target allergic conjunctivitis directly, relieving itching, redness, and watering of the eyes. Sodium cromoglicate eye drops (e.g., Opticrom) are available OTC and act as a mast cell stabiliser — they prevent histamine release rather than blocking its effects, and work best when used regularly before and during allergen exposure. Antazoline combined with xylometazoline (e.g., Otrivine Antistin) is available as a pharmacy medicine and provides both antihistamine and decongestant action in the eye. Note that azelastine eye drops are a prescription-only medicine (POM) in the UK and are not available OTC.

Decongestants such as pseudoephedrine tablets or xylometazoline nasal sprays relieve nasal congestion quickly but are not anti-allergic agents. Nasal decongestant sprays should not be used for more than 7 days due to the risk of rebound congestion (rhinitis medicamentosa). Each product type has a distinct role, and combination approaches are often most effective.

Comparing Drowsy and Non-Drowsy Allergy Treatments

One of the most clinically significant distinctions in the comparison of OTC allergy medications is sedation potential. Antihistamines are broadly divided into first-generation (sedating) and second-generation (non-sedating or low-sedating) agents, and this difference has important implications for patient safety and daily functioning.

First-generation antihistamines — including chlorphenamine (e.g., Piriton) and promethazine (e.g., Phenergan) — cross the blood-brain barrier readily, blocking central histamine receptors and causing sedation. While this can be useful in specific situations (e.g., managing itching at night or short-term sleep disturbance due to allergic symptoms), sedation impairs cognitive function and reaction times. The MHRA advises that patients taking sedating antihistamines should not drive or operate machinery if they feel drowsy or otherwise impaired; it is a criminal offence in the UK to drive while impaired by medication. Always follow the warnings on the label.

Second-generation antihistamines — such as cetirizine (e.g., Zirtek), loratadine (e.g., Clarityn), and fexofenadine (e.g., Telfast) — have much lower CNS penetration and are associated with significantly less sedation. They are generally preferred for daytime use and are recommended as first-line treatment in NICE CKS guidance for allergic rhinitis. However, cetirizine and acrivastine can still cause mild drowsiness in some individuals; fexofenadine is considered the least sedating of the commonly available options. Even with second-generation antihistamines, patients should exercise caution when first starting treatment and avoid alcohol or other CNS depressants, which may increase any sedative effect.

For most adults and children over the appropriate age threshold, non-sedating antihistamines are the preferred starting point. Sedating antihistamines may still have a role in specific circumstances but should be used with caution, particularly in older adults, who are more susceptible to anticholinergic side effects such as urinary retention, dry mouth, confusion, and increased risk of falls.

Which OTC Allergy Medication Is Right for Your Symptoms?

Selecting the most appropriate OTC allergy medication depends on the nature, severity, and pattern of symptoms. There is no single product that suits every individual, and a tailored approach — guided by symptom profile — tends to yield the best outcomes.

• Predominantly nasal symptoms (congestion, sneezing, rhinorrhoea): An intranasal corticosteroid spray is generally the most effective option, particularly for moderate-to-severe or persistent symptoms. For more immediate relief, a non-sedating oral antihistamine can be added.

• Eye symptoms (itching, redness, watering): Sodium cromoglicate eye drops or antazoline/xylometazoline eye drops provide targeted, rapid relief and can be used alongside oral antihistamines. Wearing wraparound sunglasses outdoors can also help reduce pollen exposure to the eyes.

• Skin symptoms (urticaria, itching): Oral antihistamines — particularly non-sedating agents — are the mainstay of treatment. A sedating antihistamine at night may help if itching disrupts sleep.

• Mixed or widespread symptoms: A combination of an oral antihistamine and an intranasal corticosteroid spray is often recommended, in line with NICE CKS guidance for moderate-to-severe allergic rhinitis.

• Acute nasal congestion: A short course (maximum 7 days) of a topical nasal decongestant may provide rapid relief, but should not replace anti-allergic treatment.

It is also worth considering the timing of symptoms. Seasonal allergies (e.g., grass or tree pollen) may benefit from starting treatment before the season begins, particularly with intranasal corticosteroids. Perennial allergies (e.g., dust mite or pet dander) may require year-round management, alongside allergen avoidance measures such as regular vacuuming, allergen-proof mattress covers, and keeping pets out of bedrooms. Saline nasal irrigation can also help reduce nasal symptoms and is safe for most people.

Most OTC intranasal corticosteroid sprays are licensed for adults aged 18 years and over in the UK; always check the PIL or ask a pharmacist before using in children or adolescents. Age, pregnancy, and comorbidities should also inform product selection — always check the PIL or seek pharmacist advice if uncertain.

Side Effects, Interactions and Safety Considerations

Although OTC allergy medications are generally considered safe when used as directed, they are not without risks. Awareness of potential side effects and drug interactions is essential for safe use.

Common side effects by product type:

• Sedating antihistamines: Drowsiness, dry mouth, blurred vision, urinary retention, constipation — particularly problematic in older adults.

• Non-sedating antihistamines: Generally well tolerated; mild headache or gastrointestinal upset may occur. Cetirizine and acrivastine may cause mild sedation in some users.

• Intranasal corticosteroids: Nasal dryness and epistaxis (nosebleeds) are the most common side effects. Correct technique — directing the spray towards the outer wall of the nostril, away from the nasal septum — reduces the risk of nosebleeds. With prolonged high-dose use, systemic effects are possible; in children, growth should be monitored if long-term use is required, as noted in product SmPCs.

• Topical antihistamine creams: May cause contact sensitisation or photosensitivity, particularly with prolonged or widespread use; oral antihistamines are generally preferred.

• Decongestants: Rebound congestion with prolonged use; raised blood pressure; palpitations; insomnia. Oral decongestants such as pseudoephedrine are contraindicated in patients with severe hypertension, severe coronary artery disease, or those taking monoamine oxidase inhibitors (MAOIs) — including within 14 days of stopping an MAOI. They should be used with caution in patients with mild-to-moderate hypertension, cardiovascular disease, hyperthyroidism, diabetes, glaucoma, or prostatic hypertrophy, and should not be combined with other sympathomimetics. Always check the PIL or seek pharmacist advice.

Drug interactions are an important consideration:

• Sedating antihistamines interact with alcohol, benzodiazepines, opioids, and other CNS depressants, potentiating sedation.

• Some antihistamines (e.g., loratadine) are metabolised via the CYP450 system and may interact with certain antibiotics or antifungals.

• Fexofenadine absorption is significantly reduced by grapefruit, orange, and apple juice. Fexofenadine should be taken with water, not fruit juice; if fruit juice is consumed, allow a gap of several hours around the dose.

Special populations require particular caution:

• Pregnancy and breastfeeding: Loratadine and cetirizine are generally considered the preferred oral antihistamines during pregnancy in the UK, based on NHS and UKTIS (BUMPS) guidance; however, patients should always seek individual professional advice before taking any medication during pregnancy or whilst breastfeeding.

• Children: Age restrictions vary by product; always check the licensed age range on the PIL.

• Older adults: Avoid sedating antihistamines where possible due to anticholinergic burden, fall risk, and cognitive effects.

Suspected side effects from any medication, including OTC products, can be reported via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or via the Yellow Card app. Reports from patients and healthcare professionals help improve the safety of medicines for everyone.

When to Seek Advice From a Pharmacist or GP

OTC allergy medications are appropriate for managing mild to moderate allergic symptoms in otherwise healthy adults and children. However, there are important situations where professional advice should be sought before starting or continuing treatment.

Consult a pharmacist if:

• You are unsure which product is most suitable for your symptoms.

• You are taking other medications and wish to check for interactions.

• Symptoms are new or have changed in character.

• You are pregnant, breastfeeding, or selecting a product for a young child.

• You have a chronic health condition such as hypertension, asthma, kidney disease, glaucoma, or an enlarged prostate.

See your GP if:

• Symptoms are severe, persistent (lasting more than a few weeks), or significantly affecting quality of life despite OTC treatment.

• You experience symptoms year-round that are not adequately controlled.

• There is diagnostic uncertainty — for example, if it is unclear whether symptoms are allergic or have another cause.

• You develop respiratory symptoms such as wheeze, chest tightness, shortness of breath, or a nocturnal cough, which may suggest allergic asthma and warrant further assessment.

• You develop signs of a more serious reaction, such as facial or throat swelling, difficulty breathing, or a widespread rash — these may indicate anaphylaxis. If you have a prescribed adrenaline auto-injector, use it immediately, then call 999. Do not wait to see if symptoms improve.

• You are considering allergen immunotherapy (desensitisation), which is only available on prescription and through specialist services.

NICE CKS guidance highlights that patients with poorly controlled allergic rhinitis or suspected allergic asthma should be referred for further assessment, including allergy testing where appropriate. A pharmacist is an excellent first point of contact for guidance on the comparison of OTC allergy medications and can help ensure safe, effective self-management within appropriate limits.

Frequently Asked Questions