Montelukast and leukotriene blockers — patient guide

This page covers the leukotriene receptor antagonist (LTRA) class — montelukast (Singulair, generics) and zafirlukast (Accolate). If a tablet at home is one of these, this is the page.

---

Read this first — the mood and sleep warning

Montelukast carries an FDA black-box warning and a TGA Medicines Safety Update for serious mental-health side effects.

Reported events include low mood, anxiety, irritability, aggression, agitation, hallucinations, vivid or abnormal dreams, insomnia, suicidal thoughts, and suicidal behaviour. The signal has been observed in adults, adolescents, and children. Children and adolescents carry particular vigilance.

Events can begin within days of starting montelukast — or weeks to months later.

Any new or worsening mood, sleep, or behaviour change after starting montelukast is a stop-and-contact-your-GP trigger. Not a wait-and-see.

In a mental-health crisis — call 000, or Lifeline 13 11 14.

This warning is at the top of the page on purpose. It is the single most important piece of information here. The FDA boxed warning was added in March 2020 after years of accumulating post-market signal. Most people taking montelukast will not have a mood change. The point of the warning is that for the people who do, the link is real, the signal is known, and the right action is to stop the medicine and seek review — not to push through it.

If a child or teenager is on montelukast, the parent or carer carries this watch. The conversation between the prescribing GP and the family at the time of starting should have included this — and the same conversation belongs at every follow-up review. Sleep, mood, school behaviour, irritability, nightmares, and any new anxiety are review items, every visit.

---

Find the tablet

Generic	Brand(s)	Strengths	Dosing
Montelukast	Singulair, generics	4 mg chewable (age 2 to 5); 5 mg chewable (age 6 to 14); 10 mg tablet (age 15 and over)	Once daily in the evening
Zafirlukast	Accolate	20 mg tablet	Twice daily, on an empty stomach (at least 1 hour before or 2 hours after food)

Aspartame note — phenylketonuria. The 4 mg and 5 mg montelukast chewable tablets contain aspartame, which is a phenylalanine source. Patients with phenylketonuria (PKU) should not take the chewable formulation. The swallowed tablet, the oral granules (where supplied), or a different medicine class are the alternatives.

Supply note for zafirlukast. Accolate (zafirlukast) AU prescribing has been declining for years. The pharmacist should confirm current PBS and ARTG status at dispensing — if it is not available, the conversation with the prescriber is which class to switch to (usually back to an inhaled corticosteroid, or to a combination preventer).

---

The single most important framing on this page

A preventer is not a reliever.

Montelukast is taken every day. It quietens the underlying allergic-inflammation pathway over days to weeks. It will not help in a sudden flare.

The reliever inhaler (Ventolin, Asmol, Bricanyl — salbutamol or terbutaline) opens the airway in minutes. That is the rescue medicine for sudden breathlessness.

Reliever-only treatment is a documented contributor to asthma deaths — the global asthma strategy changed in 2019 so that no one over the age of 12 should be on a reliever-only approach. If reliever use is more than twice a week (other than before exercise), the preventer regimen is not enough — that is the review-with-the-GP trigger.

---

Where montelukast sits in the asthma plan

Montelukast is rarely the first preventer chosen in Australia. The deeper preventer evidence base sits with inhaled corticosteroids. See the ICS flyer for the parallel guide.

The positioning, per the Australian Asthma Handbook and the GINA strategy:

• Mild persistent asthma — montelukast monotherapy is an alternative to a low-dose inhaled corticosteroid. It is not a replacement. Inhaled corticosteroids have the deeper exacerbation-prevention evidence. They are generally preferred. Montelukast is reasonable in three scenarios. The inhaler is not tolerated. Adherence to inhaled therapy is the rate-limiting step. Allergic rhinitis is a strong comorbid driver.
• Moderate-to-severe asthma — montelukast is an add-on at GINA step 3 and above. It sits alongside (not in place of) an inhaled corticosteroid or an ICS / long-acting beta-agonist combination. The COMPACT trial (Thorax 2003) and the Cochrane review (Ducharme 2012) showed smaller gains from adding montelukast than from stepping up to ICS/LABA in most patients. It remains a reasonable add-on where allergic rhinitis or aspirin-exacerbated respiratory disease is a major contributor.
• Exercise-induced bronchoconstriction — montelukast is an alternative to a pre-exercise reliever puff. It suits patients who prefer a daily oral preventer for exercise-triggered wheeze.
• Paediatric asthma — montelukast has historically been chosen in children where inhaler technique and adherence are genuinely difficult. The FDA black-box and TGA warning on neuropsychiatric events have raised the threshold for paediatric prescribing since 2020. Where montelukast is the right answer, parent and carer counselling about mood and sleep monitoring is non-negotiable.

The MOSAIC trial (2005, Paediatrics journal) compared montelukast to inhaled fluticasone in paediatric asthma. The inhaled corticosteroid was superior for the primary asthma-control endpoint. The Cochrane review (Chauhan and Ducharme 2014) reached the same conclusion in mixed-age populations. Inhaled corticosteroids are the preferred preventer monotherapy.

---

Where montelukast is genuinely strong

Aspirin-exacerbated respiratory disease (AERD / Samter triad)

A specific subgroup of asthma patients have the triad of:

• Asthma
• Chronic rhinosinusitis with nasal polyps
• Reactions to aspirin and other non-steroidal anti-inflammatories (NSAIDs)

In this group, the leukotriene pathway is mechanistically central. Montelukast has the strongest dedicated LTRA evidence base of any indication here. AERD management is specialist-led. Respiratory, immunology, or ENT input is typical. The regimen usually includes inhaled corticosteroid, intranasal steroid, and montelukast as an adjunct. Where appropriate and supervised, aspirin desensitisation can be added.

Has aspirin or an NSAID ever triggered breathlessness, wheeze, or facial swelling in you? The AERD diagnosis is worth raising with the GP. Avoid all NSAIDs unless cleared by the specialist team.

Allergic rhinitis (hay fever)

Montelukast has on-label use for seasonal and perennial allergic rhinitis from age 2. In current AU practice it is usually layered onto an intranasal corticosteroid spray (Nasonex, Avamys, Rhinocort, or generics). A non-sedating oral antihistamine (cetirizine, loratadine, fexofenadine) is often added on top. This combined approach is particularly useful where asthma coexists with the rhinitis. One daily tablet can cover both axes. As single-agent therapy for rhinitis alone, the intranasal steroid usually has the larger effect.

---

Tap any section below to expand the detail.

How does it work?

Leukotrienes are inflammatory signalling molecules made by mast cells and eosinophils — the same cells that drive allergic asthma, allergic rhinitis, and the AERD reaction. The cysteinyl leukotrienes (LTC4, LTD4, LTE4) bind to a receptor called CysLT1, which is densely expressed on airway smooth muscle and inflammatory cells. When the receptor is activated, the airway constricts, mucus production goes up, and more eosinophils are recruited.

Montelukast and zafirlukast block that receptor. The airway becomes less reactive to allergic triggers over days to weeks, mucus production drops, and the eosinophilic load eases.

This is mechanism-different from inhaled corticosteroids (which broadly suppress airway inflammation across multiple pathways) and from beta-agonists (which physically open the airway via a separate receptor). The clinical implication — montelukast adds something complementary to an inhaled corticosteroid in patients whose disease is heavily leukotriene-driven (AERD; allergic-rhinitis-dominant asthma; some paediatric phenotypes), and adds less in patients whose disease is more typical inhaled-corticosteroid-responsive.

The mood signal is not currently fully explained by the leukotriene-receptor mechanism. The current working hypothesis is that montelukast crosses the blood-brain barrier and may interact with neuroinflammatory or neurotransmitter systems in a subset of patients — but the mechanistic story is incomplete. The clinical management does not depend on the mechanism being settled.

Side effects in detail

The signal that drives this whole page — neuropsychiatric adverse events

Reported events include depression, anxiety, irritability, aggression, agitation, hallucinations, vivid or abnormal dreams, insomnia, and suicidal thoughts and behaviour. Reported across all age groups; particular vigilance in children and adolescents. Onset can be within days or weeks to months. The Glockler-Lauf paediatric cohort study (J Pediatr 2019) was one of the larger studies that contributed to the FDA decision to add the boxed warning. Most patients do not experience these events. The stop-and-contact-the-GP trigger applies to any new or worsening change.

Common (usually mild)

• Headache
• Upper respiratory tract infection-like symptoms
• Gastrointestinal upset — abdominal pain, nausea, loose stools
• Cough or wheeze on initiation (uncommon)

Uncommon

• Sleep disturbance, vivid dreams (overlaps with the neuropsychiatric signal — track separately)
• Skin rash, urticaria

Rare but important

• Churg-Strauss syndrome / eosinophilic granulomatosis with polyangiitis (EGPA). A rare eosinophilic vasculitis. Often appears as oral corticosteroid is tapered after montelukast is started. The current view is that montelukast usually unmasks a pre-existing eosinophilic disease rather than causing it — but the practical implication is the same. New rash that looks like small blood-spots (palpable purpura), new patchy numbness or weakness (peripheral neuropathy), worsening sinus disease, or unexplained rises in eosinophils on blood tests — all are urgent specialist-review flags.
• Hepatotoxicity. Uncommon with montelukast; more frequent with zafirlukast (case reports of cholestatic hepatitis and rarely liver failure). Jaundice, dark urine, persistent right upper quadrant pain, or unexplained nausea warrants stopping the medicine and contacting the GP for liver function tests.
• Hypersensitivity reactions. Rash, urticaria, angioedema, anaphylaxis — rare but reported. Stop the medicine and treat as for any drug hypersensitivity reaction.
• Paradoxical worsening of asthma. Rare. Worsening symptoms after initiation warrants stopping and review.

Drugs, food, and what to flag

Tell the GP or pharmacist before combining montelukast with:

• CYP3A4 inducers — phenobarbital, phenytoin, carbamazepine, rifampicin. These lower montelukast blood levels and may reduce its effect — closer asthma-control monitoring is reasonable, though the AU Product Information does not currently mandate a fixed dose adjustment.
• CYP2C8 inhibitors — gemfibrozil notably. Raises montelukast blood levels modestly. Clinical relevance is usually small at standard doses but worth flagging in polypharmacy reviews.
• Strong CYP3A4 inhibitors — clarithromycin, itraconazole, ketoconazole, ritonavir. Can raise montelukast blood levels. Usually manageable; flag at point of co-prescribing.
• Warfarin (especially with zafirlukast). Zafirlukast can raise the INR — monitor INR more frequently around initiation or dose change. Montelukast does not have a clinically significant warfarin interaction at usual doses.
• Alcohol. No direct pharmacokinetic interaction with the LTRAs themselves — but alcohol is a depressant, and the additive effect on mood and sleep matters in patients vulnerable to the neuropsychiatric signal. Particularly worth discussing with adolescents and young adults starting montelukast. Reducing or pausing alcohol intake during the first 4 to 8 weeks of therapy is a reasonable safety move, especially where mood or sleep is already fragile.
• Other CNS-active medicines — benzodiazepines, sleeping tablets, sedating antihistamines, antidepressants, antipsychotics, opioids. No specific drug-drug interaction with montelukast itself, but the cumulative load on mood and sleep matters when the LTRA neuropsychiatric signal is in play.
• Live vaccines — montelukast and zafirlukast are not immunosuppressive. There is no contraindication to MMR, varicella, BCG, yellow fever, or oral typhoid vaccines.

Food.

• Montelukast — can be taken with or without food. No specific dietary restrictions beyond the aspartame caveat in the chewable formulations (contraindicated in PKU).
• Zafirlukast — must be taken on an empty stomach. At least 1 hour before food, or at least 2 hours after. Food materially reduces absorption.

Generic substitution at the pharmacy. Generic montelukast tablets are bioequivalent to Singulair at the same strength. Substitution between manufacturer brands is usually unremarkable. The aspartame caveat applies to all chewable formulations regardless of brand.

Monitoring — what the GP checks and when

• Mood, sleep, and behaviour review at every visit. This is the highest-yield monitoring item on this medicine. For paediatric patients, the conversation includes the parent or carer — and the school, where behaviour change is being observed there. Sleep quality, nightmare frequency, new anxiety, new aggression, withdrawal, falling academic performance, or any expression of self-harm thoughts are review items every time.
• Asthma symptom review at 4 to 12 weeks after starting (or after any dose change). Sleep quality, morning chest tightness, reliever use, days off school or work, exercise tolerance.
• Written asthma action plan — every patient on a preventer should have one. Ask the GP if there isn’t one in place. Template here.
• Growth in children — height and weight plotted at each visit (good practice in any paediatric chronic-medicine review).
• Liver function tests — not routinely needed for montelukast in well patients. Lower threshold for zafirlukast, and for either drug if jaundice, dark urine, or right upper quadrant pain emerges.
• Annual flu vaccination per RACGP Red Book — reasonable in any patient with chronic airway inflammation.

Pregnancy and breastfeeding

Limited human data — used cautiously where benefit clearly outweighs risk.

• Montelukast — AU TGA pregnancy category B1 (no controlled human studies; animal studies do not show harm). Used in pregnancy where asthma control would otherwise deteriorate and inhaled-corticosteroid-based therapy is insufficient or not tolerated. Specialist input is often helpful in moderate-to-severe asthma in pregnancy.
• Zafirlukast — pregnancy data sparser; avoid where possible.
• Breastfeeding — limited human data; small amounts of montelukast pass into breast milk. The usual position is to continue a well-controlled existing regimen rather than start the medicine de novo while breastfeeding.

The bigger principle — uncontrolled asthma in pregnancy is itself a risk to the baby. Flares reduce oxygen delivery to the fetus and are associated with low birth weight and preterm birth. The right approach is not to stop a preventer on autopilot the moment a pregnancy is confirmed, but to bring it into a review conversation — usually with the GP, sometimes with a respiratory physician or maternal-fetal medicine specialist.

If a pregnancy is planned or has just been confirmed and montelukast is in the regimen — message the GP. Don’t stop on your own.

If a child is on montelukast

This is the section most parents will read three times.

The signal that matters most — mood, sleep, and behaviour.

The FDA black-box warning and the TGA Medicines Safety Update sit at the centre of how paediatric montelukast prescribing now works in Australia. The expectation at the time of starting the medicine — per current AU regulator guidance — is that the prescribing GP discusses the warning explicitly with both the patient (where age-appropriate) and the parent or carer. That conversation belongs in the medical record.

What to watch for at home — every week, especially in the first 8 weeks

• Mood — sadness, low mood, withdrawal, loss of interest in usual activities
• Anxiety — new worry, panic episodes, separation anxiety re-emerging
• Irritability and aggression — short temper, lashing out, tantrums beyond the usual baseline
• Sleep — onset difficulty, night waking, nightmares, vivid dreams
• Hallucinations — unusual things heard or seen
• School behaviour — new disengagement, new behavioural reports, falling academic performance
• Any expression of self-harm or suicidal thoughts — at any age, at any time

If any of these emerge, contact the GP the same day. In an active mental-health crisis call 000 or Lifeline 13 11 14, or Kids Helpline 1800 55 1800 for a child or young person who wants to speak to someone directly.

The wider paediatric checklist

1. Right dose for age. 4 mg chewable for age 2 to 5; 5 mg chewable for age 6 to 14; 10 mg tablet for age 15 and over. Not interchangeable.
2. Aspartame check. The chewable formulations contain aspartame — contraindicated in phenylketonuria.
3. Evening dosing, consistent anchor. Tie it to dinner, teeth-brushing, or packing the school bag. Consistency matters more than the exact clock time.
4. Sleep and mood review at every visit. Non-negotiable.
5. Growth charting. Height and weight at each review.
6. Asthma action plan. Both the family and the school need a copy.
7. Inhaler reliever still needed. Montelukast is a preventer, not a reliever — the reliever inhaler stays in the school bag.

The thing not to do — stop the medicine without a conversation if the asthma is well-controlled and there are no warning signs. Uncontrolled asthma is itself a real risk to a child. The judgement call is dose and duration and whether the right preventer class is being used — not whether asthma deserves treatment.

Stopping or pausing

• For a neuropsychiatric event — stop the medicine and contact the GP. In most cases the mood, sleep, or behaviour returns to baseline within days to a few weeks of stopping. The conversation with the GP is about what to use instead — usually a return to an inhaled corticosteroid as the preventer backbone, or a switch to a combination preventer.
• Sick day rules — montelukast is one of the medicines that is usually continued during a chest infection or flare, not stopped. The asthma action plan tells the patient which medicines step up, which stay the same, and which to start (such as a rescue prednisolone course).
• Before surgery — most anaesthetists prefer the preventer continued up to and including the morning of surgery. Confirm with the anaesthetist.
• Stopping because the asthma is well-controlled — reasonable after at least 3 months of good control, as a planned step-down with the GP. Not a “feels fine, will skip a few” decision. The asthma may stay quiet, or it may quietly drift back over weeks — the planned step-down structure exists to catch that early.

What to do in a flare-up

This is what the written asthma action plan covers — and every preventer patient should have one.

The general pattern (but follow the specific action plan):

• Reliever (Ventolin) up to every 4 hours for mild symptom increase. Not montelukast — montelukast does not work in this window.
• Increase the preventer regimen per the action plan — usually the inhaled corticosteroid component.
• Oral prednisolone if symptoms are not settling. The action plan may include a rescue prednisolone prescription to start at home.
• Call 000 if the reliever is needed more often than every 3 hours, if speaking in full sentences is difficult, if lips or fingertips turn blue, or if symptoms are not improving with the reliever.

If there isn’t a written action plan, that is the next conversation with the GP — it is the single most useful piece of paperwork in asthma management and should be reviewed at least annually. Template at National Asthma Council.

Cost

Montelukast is on the PBS for selected asthma indications under a Streamlined Authority. From 1 January 2026, the PBS co-payment is:

• General patient: up to $25.00 per script
• Concession card holder: up to $7.70 per script

Paediatric PBS access for montelukast has historically been more accessible than adult access — the prescriber can confirm the current Streamlined Authority codes and clinical criteria at the time of prescribing. Generic versions cost the same as Singulair at PBS pricing and work the same.

Zafirlukast (Accolate) is not subsidised on the PBS for routine asthma indications in current AU practice — confirm with the pharmacist at dispensing.

The actual charge may be lower if the medicine costs less than the co-payment. Confirm with the pharmacist — they can show the exact price.

---

The integrative view

Most patients (and parents) on montelukast want to know what else genuinely moves the needle — particularly given the mood signal raises the threshold for staying on the medicine longer than necessary. The framing throughout is both-and. Montelukast is doing one piece of work (blocking a specific inflammatory receptor). There are several other pieces of work that contribute to asthma and rhinitis control in parallel. Together they work better than either alone, and the goal for many patients is the lowest effective dose of the lowest-side-effect medicine alongside genuine lifestyle inputs.

Strong evidence — reliably useful

These are the interventions where the evidence is solid enough to recommend to any patient on montelukast for asthma or rhinitis.

• A written asthma action plan. Reduces hospital admissions and emergency visits more than almost any other single intervention in asthma. Free from the GP. Template from National Asthma Council.
• Smoking cessation and avoiding second-hand smoke. Single biggest lever in lung-health terms. Quitline 137848.
• Annual flu vaccination, 5-yearly pneumococcal vaccination per RACGP Red Book. Reduces exacerbation rates.
• Identify and avoid personal triggers. Pollen-driven seasonal worsening, NSAID sensitivity in the Samter triad subset, cold-air-induced bronchoconstriction, exercise-induced bronchoconstriction, perfume and chemical irritants, indoor mould, dust-mite reservoirs in bedding, gas-stove combustion products, bushfire smoke. A trigger diary for 4 weeks is genuinely useful.
• Treat allergic rhinitis properly. Uncontrolled hay fever drives post-nasal drip, mouth breathing, and airway inflammation that worsens asthma. Intranasal corticosteroid spray (Nasonex, Avamys, Rhinocort, or generics) plus a non-sedating antihistamine (cetirizine, loratadine, fexofenadine) plus saline rinses are the standard moves — montelukast can layer on top where one tablet covers both axes.
• Sleep hygiene — non-negotiable on this medicine. Consistent bedtime, screen wind-down, dark room, no caffeine after midday in adults, age-appropriate sleep duration in children. Sleep disturbance is one of the first markers of the neuropsychiatric signal — protect the baseline so the signal is visible against it rather than buried in chronic sleep debt.

Moderate evidence — likely helpful

• Vitamin D adequacy. Low vitamin D is associated with worse asthma control and more exacerbations. The strongest evidence is for correcting deficiency rather than supplementing in the already-replete — the Cochrane review by Martineau. Check serum 25(OH)D in poorly-controlled asthma, frequent winter exacerbations, housebound patients, older adults, or darker skin in southern Australia. Supplement to mid-normal if deficient.
• Breathing retraining — Buteyko, Papworth, or physiotherapy-led techniques. Moderate evidence for symptom and reliever-use improvement in asthma. Not for reducing the preventer dose without specialist review. Useful adjunct, not a substitute for the prescribed regimen.
• Aerobic exercise. 150 minutes per week of moderate-intensity aerobic activity improves symptom scores and exercise tolerance in asthma. Use the reliever before exercise if the action plan says so.
• Weight management if overweight. Even modest weight loss (5 to 10 percent of body weight) improves asthma symptom scores in patients with overlapping obesity-related airway inflammation.
• Stress, vagal tone, and the mind-body axis. Particularly relevant on montelukast given the mood signal. Slow nasal breathing (around 6 breaths per minute), meditation, and yoga have modest direct evidence in asthma — and a clear plausible benefit on the sleep-mood axis that is already under pressure on this medicine. Not a substitute for the preventer regimen.

Limited or emerging evidence

• Omega-3 (EPA + DHA). Anti-inflammatory adjunct of interest in the eosinophilic / leukotriene-driven phenotype. Whole-food sources (oily fish 2 to 3 times per week — sardines, salmon, mackerel) preferred over routine supplementation. Don’t present as a substitute for preventer therapy.
• Magnesium intake. Adequate dietary magnesium (leafy greens, legumes, nuts, seeds, wholegrains) supports bronchial smooth-muscle function. Intravenous magnesium has a defined role in acute severe asthma in hospital. Oral magnesium supplementation has not been shown to reduce chronic asthma symptoms in well-conducted trials — don’t rely on it as a preventer alternative.
• Probiotics, quercetin, butterbur, other herbal antihistamines. Mixed and modest evidence in allergic rhinitis. Not first-line. Discuss with the GP and pharmacist before adding, because herbal preparations can interact with prescribed medicines.

What does not belong in this conversation

• Stopping montelukast in favour of an unspecified “natural” alternative without a replacement plan for the asthma or rhinitis. Uncontrolled asthma is a real risk. The right move when stopping is a planned conversation with the GP about what comes next — usually an inhaled corticosteroid, sometimes a combination preventer.
• Pushing through a new mood or sleep change because the medicine is “supposed to be helping the asthma”. The mood signal is the more important signal — stop the medicine and contact the GP. The asthma management can be rebuilt around a different preventer.
• Off-label use for chronic urticaria, eosinophilic oesophagitis, or atopic dermatitis without specialist input. The evidence base is too limited to recommend self-directed use in these conditions on the patient surface.

Earning a lower load

The honest goal for many patients on montelukast — especially children and adolescents — is to use it for as long as it is genuinely needed, not by default. Once asthma is well-controlled for at least 3 months, the conversation worth having with the GP is whether the preventer regimen can be trimmed — sometimes by stepping down the dose of an inhaled corticosteroid, sometimes by removing montelukast and confirming control holds, sometimes by addressing the allergic-rhinitis driver more aggressively so the leukotriene load drops. This is a planned, monitored step-down — not an unilateral decision.

---

Track these between now and the next visit

• Mood, sleep, and behaviour — particularly in the first 8 weeks, and at any later point if something shifts. For a child, the parent or carer keeps this watch. Sleep quality, nightmares, irritability, withdrawal, school behaviour, any expression of self-harm thoughts.
• Reliever use — how many puffs per week. Anything above twice a week (other than before exercise) is a review trigger.
• Night waking — how many nights per week sleep was disrupted by cough, chest tightness, or breathlessness.
• Morning symptoms — chest tightness, cough, wheeze on waking.
• Hay fever symptoms — nasal congestion, sneezing, itchy eyes, post-nasal drip.
• Anything new bought over the counter — cold and flu tablets, NSAIDs (aspirin, ibuprofen, naproxen), herbal preparations — or any new prescription medicine.

Bring the list to the review appointment.

---

This is general information, not personal medical advice. Every patient is different. Decisions about montelukast — whether to start it, whether to continue it, what to take instead, what to combine it with — are made with the doctor who prescribed it. If anything on this page appears to contradict advice from the treating doctor, follow the doctor; they have context about the individual situation that this page cannot.

Reading this page does not establish a doctor-patient relationship with Dr Hoebing Lo. If a reader is not a current patient, please discuss montelukast with the prescribing GP, specialist, asthma nurse, or pharmacist.

The mood and sleep warning is the most important section on this page. Any new or worsening change in mood, anxiety, irritability, aggression, sleep, dreams, hallucinations, or thoughts of self-harm in a patient on montelukast — adult or child — is a stop-and-contact-the-GP trigger. In a mental-health crisis, call 000, or Lifeline 13 11 14, or Kids Helpline 1800 55 1800 for a child or young person.

About the integrative content. The lifestyle, dietary, and complementary recommendations on this page summarise current published research. Effect sizes are approximations from clinical studies — individual response will vary, and real-world results are commonly smaller than trial results because day-to-day life differs from study conditions. Supplements and herbal products are not interchangeable with prescribed medication and can interact with it. Discuss any new supplement, herbal product, or significant dietary change with the GP and pharmacist first.

Currency. This page reflects clinical practice as of the last-reviewed date. Medicine evolves; specific details may date between reviews. PBS supply and Streamlined Authority codes should be confirmed with the pharmacist at dispensing.

No commercial relationships. Dr Hoebing Lo has no financial or commercial relationship with the manufacturer of any LTRA brand or any supplement mentioned on this page.

Emergencies. For sudden severe breathlessness, an inability to speak in full sentences, lips or fingertips turning blue, chest pain, or a reliever inhaler that isn’t working — call 000 or go to the nearest emergency department. For a mental-health crisis or active suicidal thoughts — call 000, or Lifeline 13 11 14, or Kids Helpline 1800 55 1800. Do not wait, and do not message us first.