Montelukast

How to order Montelukast

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.

Montelukast on Prescriptsy

Montelukast 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.

Montelukast is a leukotriene receptor antagonist (LTRA) licensed in the United Kingdom for the prevention and long-term treatment of asthma, including exercise-induced bronchoconstriction, and for the relief of symptoms associated with seasonal and perennial allergic rhinitis.

It is available as film-coated tablets (10 mg for adults), chewable tablets (4 mg and 5 mg for children), and granules (4 mg for young children), providing age-appropriate formulations from 6 months of age upward.

Montelukast is taken once daily, usually in the evening for asthma, and provides a convenient oral treatment that complements inhaled therapies.

Asthma affects approximately 5.4 million people in the UK, and allergic rhinitis affects up to 30% of the adult population, with many patients having both conditions.

Montelukast is widely prescribed as add-on therapy for asthma when inhaled corticosteroids alone provide insufficient control, and as an alternative anti-inflammatory option in patients who cannot use or prefer to avoid inhaled treatments.

This page provides a comprehensive clinical overview of montelukast, including how it works, dosing for all age groups, side effects with a particular focus on the MHRA neuropsychiatric safety warning, precautions, and how to obtain a prescription in the UK.

Important safety information about montelukast

Before reading further, note the following key safety points about montelukast.

• The MHRA has issued specific warnings about neuropsychiatric side effects, including sleep disturbances, nightmares, agitation, depression, and, rarely, suicidal thoughts. Patients, parents, and carers must be aware of these risks and report any behavioural or mood changes promptly.
• Montelukast is a preventive treatment and must not be used to relieve acute asthma attacks. Always carry a reliever inhaler.
• Do not stop your inhaled corticosteroid when starting montelukast unless specifically advised by your prescriber.
• Seek urgent medical advice if you experience signs of a systemic allergic reaction or symptoms suggestive of Churg-Strauss syndrome.

What are leukotrienes

Leukotrienes are a family of potent inflammatory mediators derived from arachidonic acid through the 5-lipoxygenase pathway.

The cysteinyl leukotrienes (LTC4, LTD4, and LTE4) are released from activated mast cells, eosinophils, basophils, and macrophages during allergic and inflammatory responses.

In the airways, cysteinyl leukotrienes cause bronchoconstriction (tightening of the smooth muscle surrounding the bronchi), increase vascular permeability (leading to airway oedema), stimulate mucus secretion, and promote eosinophil recruitment to the bronchial mucosa.

These effects contribute significantly to the airway obstruction, inflammation, and hyperresponsiveness that characterise asthma.

In the nose, leukotrienes contribute to the congestion, rhinorrhoea, and sneezing of allergic rhinitis.

Unlike histamine, which primarily causes sneezing and itching, leukotrienes are particularly important mediators of nasal congestion.

This explains why montelukast can be effective for rhinitis symptoms that do not respond fully to antihistamines alone.

How montelukast works: mechanism of action

Montelukast selectively blocks the cysteinyl leukotriene type 1 (CysLT1) receptor, which mediates the bronchoconstrictive, pro-inflammatory, and secretory effects of cysteinyl leukotrienes in the airways and nasal mucosa.

By occupying the CysLT1 receptor, montelukast prevents LTD4 (the most potent bronchoconstrictor leukotriene) and its related metabolites from binding and activating the receptor.

The clinical effects of CysLT1 antagonism include relaxation of airway smooth muscle (bronchodilation), reduced airway oedema and mucus production, decreased eosinophilic inflammation, and reduced bronchial hyperresponsiveness.

These effects develop within hours of the first dose and are sustained with daily use.

In allergic rhinitis, CysLT1 antagonism reduces nasal congestion, rhinorrhoea, and sneezing, particularly when used in combination with antihistamines for comprehensive symptom control.

Montelukast provides an anti-inflammatory effect through a different pathway from corticosteroids. Corticosteroids broadly suppress gene transcription of multiple inflammatory mediators, whereas montelukast specifically targets the leukotriene pathway.

This complementary mechanism explains why adding montelukast to inhaled corticosteroid therapy can provide additional benefit in patients with incompletely controlled asthma.

MHRA neuropsychiatric safety warning

The MHRA has issued specific safety advice regarding neuropsychiatric adverse reactions associated with montelukast. Healthcare professionals, patients, parents, and carers must be informed of these risks before treatment is started.

Reported neuropsychiatric effects include abnormal dreams, nightmares, insomnia, night terrors, sleepwalking, agitation, irritability, aggression, restlessness, tremor, anxiety, depression, disorientation, attention disturbance, memory impairment, obsessive-compulsive symptoms, hallucinations, dysphemia (stuttering), and, rarely, suicidal ideation and behaviour.

These effects have been reported in both adults and children, including very young children, and can develop at any time during treatment, from the first dose to after months of use.

The mechanism underlying these neuropsychiatric effects is not fully understood but may relate to the expression of CysLT1 receptors in the central nervous system, including brain regions involved in mood, behaviour, and sleep regulation.

Genetic variation in leukotriene pathway enzymes may contribute to individual susceptibility.

Healthcare professionals should actively ask about neuropsychiatric symptoms at each review.

Parents and carers of children taking montelukast should be vigilant for changes in behaviour, mood, or sleep patterns.

If neuropsychiatric symptoms develop, the prescriber should review the treatment and consider discontinuation.

In some patients, symptoms resolve promptly on stopping montelukast, but there are reports of symptoms persisting after discontinuation.

Clinical evidence and national guidelines

The efficacy of montelukast in asthma has been demonstrated in numerous randomised controlled trials.

In adults, montelukast as monotherapy improves lung function, reduces daytime and night-time symptoms, and decreases reliever inhaler use compared with placebo.

However, montelukast monotherapy is generally less effective than low-dose inhaled corticosteroids for most patients with persistent asthma.

The most common role for montelukast in UK clinical practice is as add-on therapy.

NICE Guideline NG80 recommends adding an LTRA (montelukast is the only LTRA currently marketed in the UK) at Step 3 of the treatment pathway if a low-dose ICS plus LABA combination does not achieve adequate control.

BTS/SIGN guidelines also recommend LTRAs as an add-on option. In exercise-induced asthma, montelukast has demonstrated efficacy in attenuating exercise-induced bronchoconstriction when taken as a single daily dose.

For allergic rhinitis, trials have shown that montelukast alone is comparable in efficacy to some antihistamines, and the combination of montelukast with an antihistamine provides greater symptom relief than either agent alone, particularly for nasal congestion.

Montelukast may be particularly useful for patients with concurrent asthma and allergic rhinitis, as a single daily dose addresses both conditions.

In children, montelukast has been shown to reduce asthma exacerbations, improve symptom control, and allow reductions in inhaled corticosteroid dose when used as add-on therapy.

Its availability as a chewable tablet and granule formulation makes it particularly convenient for young children who may have difficulty with inhaler devices.

Dosage and administration

Montelukast is taken once daily. The dose depends on the patient's age and the indication.

Adults and adolescents (15 years and over)

One 10 mg film-coated tablet once daily in the evening for asthma, or once daily at any time for allergic rhinitis. If both conditions are present, a single evening dose is sufficient.

Children aged 6 to 14 years

One 5 mg chewable tablet once daily in the evening for asthma. The chewable tablet should be chewed thoroughly before swallowing.

Children aged 2 to 5 years

One 4 mg chewable tablet or one sachet of 4 mg granules once daily in the evening.

Granules can be placed directly on the tongue, mixed into cold or room-temperature soft food (such as yoghurt), or added to cold baby formula or breast milk.

The mixture should be given within 15 minutes. Do not dissolve granules in other liquids.

Children aged 6 months to under 2 years (asthma only)

One sachet of 4 mg granules once daily in the evening. This indication is for asthma only; montelukast is not licensed for allergic rhinitis in children under 2 years.

Practical guidance

Montelukast can be taken with or without food.

For asthma, evening dosing is recommended because leukotriene levels are typically highest during the night, and evening administration provides optimal airway protection during the early morning hours when asthma symptoms are often worst.

No dose adjustment is required for mild to moderate hepatic or renal impairment.

Side effects of montelukast

Common side effects

The most frequently reported side effects are headache and abdominal pain. In children, thirst and hyperkinesia (increased physical activity) have also been commonly reported. Diarrhoea, nausea, and vomiting may occur in some patients.

Neuropsychiatric side effects

As detailed in the MHRA safety warning section above, neuropsychiatric adverse effects are a clinically important concern.

Sleep disturbances (insomnia, nightmares, abnormal dreams, night terrors, and sleepwalking), agitation, irritability, aggression, anxiety, depression, attention difficulties, memory impairment, and, rarely, suicidal ideation and behaviour have been reported.

Parents of children taking montelukast should be specifically counselled about behavioural changes and should contact their prescriber if these develop.

Allergic and hypersensitivity reactions

Uncommon allergic reactions include rash, urticaria (hives), pruritus (itching), and angioedema (swelling of the face, lips, tongue, or throat).

Very rare but serious reactions include anaphylaxis, erythema nodosum, erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis.

Seek immediate medical attention if you experience swelling of the face or throat, difficulty breathing, or a widespread blistering rash.

Other rare side effects

Hepatitis and cholestatic liver disease have been reported rarely.

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) has been observed in a small number of patients, sometimes during reduction of oral corticosteroid therapy.

Symptoms include worsening asthma, flu-like illness, skin rash, numbness or tingling, and cardiac or pulmonary complications.

Arthralgia (joint pain), myalgia (muscle pain), muscle cramps, and easy bruising or bleeding due to thrombocytopenia have been reported uncommonly.

When to seek medical advice

Contact your GP, asthma nurse, or NHS 111 if you experience new or worsening behavioural or mood changes, persistent sleep disturbances, increased asthma symptoms, or any unexpected side effects.

Seek emergency care by calling 999 or attending A&E if you experience a severe allergic reaction (swelling of the face or throat, difficulty breathing, widespread hives), a severe asthma attack not responding to your reliever inhaler, or symptoms of Churg-Strauss syndrome.

Report any suspected adverse reactions via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk .

Warnings and precautions

Neuropsychiatric monitoring

Prescribers must inform patients, parents, and carers about the risk of neuropsychiatric adverse effects before starting montelukast.

Active monitoring for these effects should be part of every clinical review. If neuropsychiatric symptoms develop, treatment should be reassessed and discontinuation considered.

The MHRA advises that the benefits and risks of continuing treatment should be evaluated for each patient individually.

Not a reliever

Montelukast is a preventive treatment and provides no relief of acute bronchospasm.

All patients with asthma must carry a short-acting beta-2 agonist reliever inhaler (such as salbutamol) for use during acute symptoms.

If reliever use is increasing, this indicates worsening asthma control and the need for medical review.

Relationship with inhaled corticosteroids

Montelukast should not be substituted for inhaled corticosteroids. When montelukast is added to existing ICS therapy, the ICS dose should not be reduced or stopped without medical advice.

If your prescriber does recommend a stepwise reduction in ICS dose, this should be done gradually under supervision.

Aspirin-sensitive asthma

Patients with aspirin-sensitive asthma should continue to avoid aspirin and NSAIDs while taking montelukast. Although montelukast blocks leukotriene-mediated bronchoconstriction, it does not provide complete protection against aspirin-induced respiratory reactions.

Churg-Strauss syndrome

In rare cases, patients receiving LTRAs have developed eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome).

This has sometimes occurred during corticosteroid dose reduction, raising the question of whether unmasking of a pre-existing condition may be involved.

Regardless of the mechanism, new onset of rash, neuropathy, worsening pulmonary symptoms, sinus disease, or cardiac complications in a patient taking montelukast should prompt urgent investigation.

Pregnancy and breastfeeding

Limited human data on montelukast use in pregnancy have not shown an increased risk of malformations.

NICE and BTS/SIGN guidelines advise that LTRAs can be continued during pregnancy if the patient was taking them before conception and they are needed for asthma control.

However, inhaled corticosteroids remain the preferred first-line preventer in pregnancy. Montelukast is excreted in breast milk in small amounts. Discuss with your prescriber if you are breastfeeding.

How to get a montelukast prescription in the UK

Montelukast is classified as a prescription-only medicine (POM) in the UK.

It can be prescribed by your GP, asthma nurse, paediatrician, respiratory specialist, or an authorised online prescriber registered with the GPhC.

A clinical assessment of your asthma control or allergic rhinitis symptoms is needed before prescribing.

Generic montelukast is widely available on the NHS and is the formulation most commonly dispensed.

Branded versions (such as Singulair) may also be prescribed but are identical in active ingredient and dose.

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

Living with asthma and allergic rhinitis: practical management

Effective management of asthma and allergic rhinitis involves a combination of regular medication, trigger avoidance, and self-monitoring.

For asthma, use your preventer inhaler every day as prescribed, even when you feel well. Monitor your peak flow at home if advised.

Keep a written personalised asthma action plan agreed with your GP or asthma nurse. Attend annual asthma reviews.

For allergic rhinitis, identify your triggers (pollen, house dust mites, pet dander, mould) and take practical steps to reduce exposure.

Nasal corticosteroid sprays, antihistamines, and montelukast can be used in combination for comprehensive symptom control during peak allergy seasons.

Exercise is beneficial for both asthma and overall health. If exercise triggers your asthma, speak with your prescriber about optimising your treatment. Montelukast has demonstrated efficacy in reducing exercise-induced bronchoconstriction and may allow patients to exercise more comfortably.

When to seek urgent medical advice

Seek urgent help if your asthma symptoms worsen despite regular treatment, if your reliever inhaler is not lasting 4 hours, if you are too breathless to speak, eat, or sleep, or if your peak flow readings are falling.

Call 999 or attend A&E for a severe asthma attack with bluish lips, drowsiness, rapid breathing, or inability to speak in full sentences.

Contact your GP or NHS 111 if you notice any neuropsychiatric changes in yourself or your child while taking montelukast.

Report any suspected adverse reactions via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk .

Sources

• Montelukast 10 mg film-coated tablets, Summary of Product Characteristics (EMC)
• Montelukast, British National Formulary (BNF)
• NICE NG80: Asthma: diagnosis, monitoring and chronic asthma management
• MHRA Drug Safety Update: Montelukast neuropsychiatric reactions
• Montelukast, NHS
• MHRA Yellow Card Scheme