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Ketotifen 1mg/5ml elixir (Zaditen) 300ml
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Ketotifen 1mg/5ml Elixir (Zaditen) 300ml is a sugar-free, strawberry-flavoured liquid medicine that combines antihistamine effects with mast cell stabilisation to help manage persistent allergies and mast cell activation syndrome (MCAS). It is usually taken twice daily with food and is suitable for adults and children when prescribed and monitored by a healthcare professional.
Ketotifen 1mg/5ml Elixir (Zaditen) 300ml is a prescription only oral solution. It contains ketotifen, a medicine with both antihistamine and mast cell stabilising effects. Each 5ml spoonful provides 1mg of ketotifen in a sugar free, strawberry flavoured base. Ketotifen 1mg/5ml elixir comes in a 300ml bottle with a dosing device so you can measure each dose accurately [1].
Ketotifen for long term use
Unlike many standard antihistamine syrups, clinicians use Ketotifen 1mg/5ml Elixir (Zaditen) 300ml for regular, long term treatment. They often prescribe it for people whose allergy symptoms keep coming back. Clinicians also use it for suspected or confirmed mast cell activation syndrome (MCAS), where mast cells react too easily and “over fire” [2][4]. Ketotifen calms mast cells and blocks histamine. This helps reduce how often flares occur and how severe they feel, instead of only treating each reaction after it starts.
The benefits of ketotifen liquid
The liquid format makes this medicine useful when tablets are not a good fit. Children can take it more easily than tablets. Adults who struggle to swallow tablets may also prefer it. Patients who need fine dose adjustments can measure the solution accurately in millilitres. The sugar free formulation helps people who need to limit sugar intake, such as some patients with diabetes. They should still follow personalised advice from their clinician [1].
In summary, Ketotifen 1mg/5ml Elixir (Zaditen) 300ml offers:
A liquid alternative to ketotifen tablets
Dual action as an antihistamine and mast cell stabiliser
A sugar free, strawberry flavoured formula suitable for many adults and children
A practical option for long term management of allergic conditions and MCAS under specialist guidance [1][2][4][5].
Additional information
Quantity
1 x 300ml, 2 x 300ml, 3 x 300ml, 4 x 300ml
MOJO WISDOM
Take control of your health by understanding your condition and what this medication is doing for you.
Ketotifen 1mg/5ml Elixir (Zaditen) 300ml is a strawberry flavoured, sugar free liquid medicine that combines antihistamine action with mast cell stabilising effects. It is often prescribed for children and adults who live with persistent allergies or mast cell activation syndrome (MCAS) and need something gentler than constant “fire fighting” with short acting antihistamines [1], [2]. In this guide, we will walk through what it is, how it works, who it is for, how to use it safely, and what to expect in real life.
Key takeaways
Ketotifen 1mg/5ml Elixir (Zaditen) 300ml is a liquid form of ketotifen used to manage allergic rhinitis, chronic allergies and, in some cases, mast cell activation syndrome (MCAS) [1],[ 2], [3].
The active ingredient, ketotifen, blocks histamine and helps stabilise mast cells so that it can reduce sneezing, runny nose, itchy eyes and some multi-system MCAS symptoms [2], [4].
The elixir is sugar-free and strawberry-flavoured, which makes it easier for children and adults who dislike or cannot swallow tablets [1].
It is usually taken twice daily with food and is intended for regular, ongoing use rather than “as needed” rescue dosing [1], [2].
Ketotifen 1mg/5ml Elixir (Zaditen) 300ml should always be used under medical supervision, with careful attention to side effects, drug interactions and individual MCAS treatment plans [1], [4], [5].
Overview of Ketotifen 1mg/5ml Elixir (Zaditen) 300ml
Key takeaways
Designed for long-term management of allergic rhinitis, chronic allergies and some MCAS presentations [1], [2], [3].
Combines antihistamine activity with mast cell stabilisation, which can reduce both day-to-day symptoms and flare frequency [2], [4], [5].
Liquid format is useful for children, tablet-averse adults and fine-tuning doses.
Benefits usually build over time rather than providing instant relief.
Works best as part of a broader plan that may include trigger management, other antihistamines and, in MCAS, broader lifestyle and medical strategies [4], [5].
For many families, allergies are not just a “hay fever season” problem. They are a year-round background noise: constant sneezing, blocked noses, itchy eyes, rashes and disturbed sleep.
Allergic rhinitis
NICE guidance highlights how allergic rhinitis and related conditions can affect school, work, and quality of life when poorly controlled [3]. Ketotifen 1mg/5ml Elixir (Zaditen) 300ml is one of the options clinicians may turn to when simple measures and standard antihistamines are not enough.
Mast cell activation syndrome
The medicine is also used in some people with mast cell activation syndrome. MCAS is a condition in which mast cells release their chemical messengers too easily, causing symptoms across several organs at once, from the skin and gut to the heart and brain [4], [5]. In this context, ketotifen’s mast cell stabilising effect is just as important as its antihistamine action.
Because Ketotifen 1mg/5ml Elixir (Zaditen) 300ml is taken regularly, it fits into a preventive strategy rather than a purely reactive one. Think of it less as a fire extinguisher and more as better wiring in the building. It is not suitable for everyone, and it does have side effects and interaction risks, but for the right person, it can be a valuable part of a long-term plan [1], [2].
Active ingredient in ketotifen 1mg/5ml elixir (Zaditen) 300ml
The active ingredient in Ketotifen 1mg/5ml Elixir (Zaditen) 300ml is ketotifen, present as ketotifen hydrogen fumarate. Each 5ml of elixir contains 1mg of ketotifen [1].
Ketotifen is classified as a non-competitive H1 antihistamine with additional mast cell-stabilising properties. In simple terms, it blocks the effect of histamine at H1 receptors and also makes mast cells less likely to “degranulate” and release histamine and other mediators in the first place [2], [5]. This dual mechanism is what sets it apart from many over-the-counter antihistamines that only block histamine.
The elixir also contains excipients such as sweeteners, flavourings and preservatives. These are listed in the patient information leaflet and are important for people with specific intolerances or dietary needs, so it is always worth checking the leaflet carefully or asking your pharmacist to go through it with you [1].
What is ketotifen 1mg/5ml elixir (Zaditen) 300ml for?
Clinicians prescribe Ketotifen 1mg/5ml Elixir (Zaditen) 300ml primarily for the prevention and long-term management of allergic conditions such as seasonal and perennial allergic rhinitis, chronic allergic conjunctivitis and other persistent allergy-related symptoms [1], [2], [3]. It is particularly useful when symptoms are frequent, disruptive and not well controlled with standard non-sedating antihistamines alone.
In practice, that might look like a child who sneezes, sniffs, and rubs their eyes every day through spring and summer despite regular cetirizine, or an adult whose nose, eyes, and skin flare with dust, pets, and perfumes all year round. For these patients, adding a mast cell stabiliser such as ketotifen can sometimes reduce the “background level” of reactivity and make life more predictable [2], [5].
Ketotifen and mast cell activation syndrome
A growing number of specialists also use ketotifen as part of the management of mast cell activation syndrome. MCAS is not yet fully standardised across guidelines. Still, expert groups describe it as a condition where mast cells are overly sensitive and release mediators in response to triggers that would not bother most people [4], [5]. Symptoms can include flushing, hives, abdominal pain, diarrhoea, palpitations, headaches and brain fog, often in clusters.
In this setting, Ketotifen 1mg/5ml Elixir (Zaditen) 300ml is rarely used alone. It usually sits alongside H1 and H2 antihistamines, trigger avoidance, dietary changes and sometimes other mast cell-directed treatments. Its role is to dampen down mast cell activity over time, helping to reduce the intensity and frequency of flares [4], [5].
How does Ketotifen 1mg/5ml Elixir (Zaditen) 300ml work?
To understand how Ketotifen 1mg/5ml Elixir (Zaditen) 300ml works, it helps to picture two things happening at once: histamine being blocked and mast cells being calmed.
Ketotifen as a histamine blocker
Histamine is one of the main chemicals released during an allergic reaction. It binds to H1 receptors in the nose, eyes, skin and elsewhere, causing sneezing, itching, swelling and extra mucus. Ketotifen binds to H1 receptors and prevents histamine from binding, reducing classic allergy symptoms like runny nose, itchy eyes, and hives [2], [3].
Ketotifen as a mast cell stabiliser
At the same time, ketotifen helps stabilise mast cells. Mast cells are immune cells packed with granules containing histamine and many other mediators. In allergic disease and MCAS, these cells can become “twitchy” and degranulate too easily. Laboratory and clinical data suggest that ketotifen reduces this tendency to degranulate, so fewer mediators are released into the tissues and bloodstream [2], [4], [5].
The dual action of ketotifen
Because of this dual action, ketotifen 1mg/5ml elixir (Zaditen) 300ml is better thought of as a preventive controller than a simple “take it when you sneeze” antihistamine. It needs time to build up in the body and influence mast cell behaviour. Many patients only start to notice the full benefit after several weeks of regular use, especially when MCAS is involved [1], [4].
Some people feel a little drowsy in the first week or two. This is because ketotifen can cross the blood–brain barrier and has a mild sedating effect in some patients, particularly at the start of treatment. For most, this settles with time as the body adapts [1], [2].
How to use Ketotifen 1mg/5ml Elixir (Zaditen) 300ml
Always follow the instructions given by your own doctor or pharmacist, as they know your complete medical history. The guidance below is a general overview based on product and formulary information [1], [2].
First, shake the bottle gently before each dose to make sure the medicine is evenly mixed. Use the supplied spoon or oral syringe to measure the correct volume; kitchen teaspoons are not accurate.
Ketotifen adult dose
The usual adult and older child dose is 5ml (1mg) twice daily, taken with food to reduce the risk of stomach upset. Younger children may need a lower dose based on their weight.
When to take ketotifen?
Try to take ketotifen 1mg/5ml elixir (Zaditen) 300ml at the exact times each day, for example, breakfast and evening meal. Building it into a routine makes it easier to remember and keeps the level of medicine in your system steady. If you forget a dose, take it when you remember, unless it is almost time for the next one. Do not double up to make up for a missed dose [1].
Can you stop taking ketotifen suddenly?
If you and your clinician decide to stop ketotifen after long-term use, do not stop suddenly. Product information suggests tapering over 2 to 4 weeks to reduce the risk of symptoms rebounding [1]. Your prescriber will advise a step-down plan that suits your situation.
Warnings and precautions for ketotifen 1mg/5ml elixir (Zaditen) 300ml
Ketotifen 1mg/5ml elixir (Zaditen) 300ml is not suitable for everyone. You should not take it if you are allergic to ketotifen or any of the other ingredients listed in the patient information leaflet [1]. Always mention any previous serious reactions to medicines to your prescriber.
Use extra caution if you have a history of epilepsy or seizures, as ketotifen may lower the seizure threshold in some patients [1], [2]. Your clinician will weigh up the risks and benefits and may choose an alternative if your seizure risk is high.
Liver problems also require careful assessment, as the liver processes the medicine, and dose adjustments or extra monitoring may be required.
During the first few days of treatment, ketotifen 1mg/5ml elixir (Zaditen) 300ml can cause drowsiness or slower reaction times. Until you know how it affects you, avoid driving, cycling in busy traffic or operating machinery.
Alcohol and other sedating medicines can increase this effect, so combining them is generally discouraged [1], [2].
Pregnancy and breastfeeding require a careful, case-by-case decision. Human data are limited, and product information usually advises avoiding ketotifen in pregnancy and while breastfeeding unless a specialist recommends it and feels the benefits clearly outweigh any potential risks [1], [2]. If you are pregnant, planning a pregnancy or breastfeeding, always discuss this with your prescriber before starting or continuing the elixir.
Side effects of ketotifen 1mg/5ml elixir (Zaditen) 300ml
Like all medicines, ketotifen 1mg/5ml elixir (Zaditen) 300ml can cause side effects, although not everyone will experience them. The most frequently reported include drowsiness, dry mouth, mild dizziness and occasional stomach upset, especially during the first week or two of treatment [1], [2]. Many people find these early effects fade as their body adapts.
Less common side effects can include weight gain, increased appetite and mild irritability or sleep disturbance, particularly in children. These are worth monitoring and discussing at follow-up appointments, as dose adjustments or timing tweaks can sometimes help [1].
Serious side effects are rare but important to recognise. These include signs of an allergic reaction (such as rash, swelling of the face or throat, difficulty breathing), yellowing of the skin or eyes that could suggest liver problems, or seizures in someone who has not had them before. If any of these occur, stop taking the medicine and seek urgent medical help [1], [2].
If you notice any side effects, even if they are not listed in the leaflet, it is always worth mentioning them to your pharmacist or doctor. They can help you decide whether to continue, adjust the dose or try an alternative.
This Medical Mojo treatment?plan infographic on medicalmojo.co.uk summarises how to use Ketotifen 1mg/5ml Elixir (Zaditen): take it on a regular schedule, watch for drowsiness when you first start, and keep avoiding known allergy triggers as part of your long?term plan.
Drug interactions with ketotifen 1mg/5ml elixir (Zaditen) 300ml
Ketotifen 1mg/5ml elixir (Zaditen) 300ml can interact with other medicines, so it is essential to share a complete list of everything you take, including over-the-counter products and herbal supplements [1], [2].
Sedating medicines such as some antidepressants, antipsychotics, strong painkillers, older antihistamines and sleeping tablets can increase drowsiness when combined with ketotifen. Alcohol has a similar effect. Your prescriber may advise avoiding these combinations or using extra caution if they are essential [1].
Product information also warns about combining ketotifen with certain oral diabetes medicines, as there have been reports of low platelet counts (thrombocytopenia) when they are used together [1]. If you have diabetes and take tablets or insulin, your clinician will check for any specific risks before prescribing the elixir.
In people with asthma who use inhalers or other allergy medicines, ketotifen is sometimes added as part of a broader plan. This is usually safe, but the exact combination should always be agreed with your specialist or GP so that doses and timings work together rather than against each other [2], [4].
FAQ: Ketotifen 1mg/5ml Elixir (Zaditen) 300ml
What is ketotifen 1mg/5ml elixir (Zaditen) 300ml?
It is a prescription liquid medicine containing ketotifen, an antihistamine with mast cell-stabilising properties, used to help manage persistent allergies and in some cases of mast cell activation syndrome (MCAS).
Who is ketotifen 1mg/5ml elixir (Zaditen) 300ml for?
Clinicians may prescribe it for adults and children with troublesome allergic rhinitis or chronic allergy symptoms, and for selected patients with MCAS under specialist care.
Where can I buy ketotifen 1mg/5ml elixir in the UK?
Ketotifen is a prescription medicine and requires a prescription. You can buy it from reputable online pharmacies, such as mkdicalmojo.co.uk
Is ketotifen 1mg/5ml elixir (Zaditen) 300ml suitable for children?
Yes, it can be used in children when prescribed by a doctor, with the dose adjusted according to age and weight. The elixir format is often chosen for younger patients who cannot swallow tablets.
How long does ketotifen 1mg/5ml elixir (Zaditen) 300ml take to work?
Some people notice improvements within a few days, but full benefits, especially for MCAS, may take several weeks of regular use as mast cells gradually become less reactive.
Can I use ketotifen 1mg/5ml elixir (Zaditen) 300ml as needed?
It is usually prescribed as a regular, twice-daily medicine rather than an “as-needed” treatment. Taking it only occasionally is unlikely to give the full preventive benefit.
Does ketotifen 1mg/5ml elixir (Zaditen) 300ml cause drowsiness?
Drowsiness is one of the most common early side effects, especially in the first week or two. Many people find it settles with time, but you should avoid driving or operating machinery until you know how you react.
Can I drink alcohol while taking ketotifen 1mg/5ml elixir (Zaditen) 300ml?
Alcohol can increase drowsiness and impair coordination when combined with ketotifen, so it is generally best avoided or kept to a minimum while you are on this medicine.
Is ketotifen 1mg/5ml elixir (Zaditen) 300ml sugar?free?
Yes, the elixir is formulated without standard sugar and instead uses sweeteners such as maltitol. This can be helpful for people who need to limit sugar, although anyone with diabetes should still check with their clinician.
Can I take ketotifen 1mg/5ml elixir (Zaditen) 300ml with other antihistamines?
Sometimes, yes. In MCAS and severe allergy, specialists may combine ketotifen with other H1 or H2 antihistamines. This should always be done under medical supervision to avoid excessive sedation or interactions.
What should I do if I miss a dose?
Take the missed dose when you remember, unless it is nearly time for your next one. If it is close, skip the missed dose and continue as usual. Do not double the dose to catch up.
Can I stop ketotifen 1mg/5ml elixir (Zaditen) 300ml suddenly?
If you have been taking it for a long time, do not stop suddenly without advice. Your clinician may suggest tapering the dose over a few weeks to reduce the risk of symptoms flaring up again.
Is ketotifen 1mg/5ml elixir (Zaditen) 300ml safe in pregnancy?
Product and formulary information generally advise avoiding ketotifen during pregnancy unless a specialist feels the benefits clearly outweigh the risks. Always speak to your doctor if you are pregnant or planning a pregnancy.
Can I use ketotifen 1mg/5ml elixir (Zaditen) 300ml while breastfeeding?
Ketotifen may pass into breast milk, and routine use while breastfeeding is usually not recommended unless advised by a specialist. Discuss this with your clinician before starting or continuing treatment.
Does ketotifen 1mg/5ml elixir (Zaditen) 300ml help MCAS?
Evidence and expert opinion suggest that ketotifen can be helpful in some people with MCAS by stabilising mast cells and reducing mediator release, particularly when used as part of a wider treatment plan.
Disclaimer: This article is for informational purposes only and does not replace professional medical advice.
4 Weiler, C.R. et al. (2019) ‘AAAAI Mast Cell Disorders Committee Work Group Report: mast cell activation syndrome (MCAS) diagnosis and management’, Journal of Allergy and Clinical Immunology, 144(4), pp. 883–896. Available at: https://www.jacionline.org/article/S0091-6749(19)30409-2/fulltext (Accessed: 24 November 2025).
5 Castells, M. and Butterfield, J. (2019) ‘Mast cell activation syndrome and mastocytosis: initial treatment options and long?term management’, Journal of Allergy and Clinical Immunology: In Practice, 7(4), pp. 1097–1106. Available at: https://www.jaci-inpractice.org/article/S2213-2198(18)31120-7/fulltext (Accessed: 24 November 2025).
