4.1. Therapeutic indications

Singulair is indicated in the treatment of asthma as add-on therapy in those patients with mild to moderate persistent asthma who are inadequately controlled on inhaled corticosteroids and in whom “as-needed” short acting β-agonists provide inadequate clinical control of asthma. In those asthmatic patients in whom Singulair is indicated in asthma, Singulair can also provide symptomatic relief of seasonal allergic rhinitis.

Singulair is also indicated in the prophylaxis of asthma in which the predominant component is exercise-induced bronchoconstriction.

4.2. Posology and method of administration

Posology

The recommended dose for adults and adolescents 15 years of age and older with asthma, or with asthma and concomitant seasonal allergic rhinitis, is one 10 mg tablet daily to be taken in the evening.

General recommendations

The therapeutic effect of Singulair on parameters of asthma control occurs within one day. Singulair may be taken with or without food. Patients should be advised to continue taking Singulair even if their asthma is under control, as well as during periods of worsening asthma. Singulair should not be used concomitantly with other products containing the same active ingredient, montelukast.

No dosage adjustment is necessary for the elderly, or for patients with renal insufficiency, or mild to moderate hepatic impairment. There are no data on patients with severe hepatic impairment. The dosage is the same for both male and female patients.

Therapy with Singulair in relation to other treatments for asthma

Singulair can be added to a patient's existing treatment regimen.

Inhaled corticosteroids: Treatment with Singulair can be used as add-on therapy in patients when inhaled corticosteroids plus “as needed” short acting β-agonists provide inadequate clinical control. Singulair should not be abruptly substituted for inhaled corticosteroids (see section 4.4).

Paediatric population

Do not give Singulair 10 mg film-coated tablets to children less than 15 years of age. The safety and efficacy of Singulair 10 mg film-coated tablets in children less than 15 years has not been established.

5 mg chewable tablets are available for paediatric patients 6 to 14 years of age.

4 mg chewable tablets are available for paediatric patients 2 to 5 years of age.

4 mg granules are available for paediatric patients 6 months to 5 years of age.

Method of administration

Oral use.

4.3. Contraindications

Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

4.4. Special warnings and precautions for use

Patients should be advised never to use oral montelukast to treat acute asthma attacks and to keep their usual appropriate rescue medication for this purpose readily available. If an acute attack occurs, a short-acting inhaled β-agonist should be used. Patients should seek their doctors' advice as soon as possible if they need more inhalations of short-acting β-agonists than usual.

Montelukast should not be substituted abruptly for inhaled or oral corticosteroids.

There are no data demonstrating that oral corticosteroids can be reduced when montelukast is given concomitantly.

In rare cases, patients on therapy with anti-asthma agents including montelukast may present with systemic eosinophilia, sometimes presenting with clinical features of vasculitis consistent with Churg-Strauss syndrome, a condition which is often treated with systemic corticosteroid therapy. These cases have been sometimes associated with the reduction or withdrawal of oral corticosteroid therapy. Although a causal relationship with leukotriene receptor antagonism has not been established, physicians should be alert to eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy presenting in their patients. Patients who develop these symptoms should be reassessed and their treatment regimens evaluated.

Treatment with montelukast does not alter the need for patients with aspirin-sensitive asthma to avoid taking aspirin and other non-steroidal anti-inflammatory drugs.

Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Neuropsychiatric events have been reported in adults, adolescents, and children taking Singulair (see section 4.8). Patients and physicians should be alert for neuropsychiatric events. Patients and/or caregivers should be instructed to notify their physician if these changes occur. Prescribers should carefully evaluate the risks and benefits of continuing treatment with Singulair if such events occur.

4.5. Interaction with other medicinal products and other forms of interaction

Montelukast may be administered with other therapies routinely used in the prophylaxis and chronic treatment of asthma. In drug-interactions studies, the recommended clinical dose of montelukast did not have clinically important effects on the pharmacokinetics of the following medicinal products:

theophylline, prednisone, prednisolone, oral contraceptives (ethinyl estradiol/norethindrone 35/1), terfenadine, digoxin and warfarin.

The area under the plasma concentration curve (AUC) for montelukast was decreased approximately 40% in subjects with co-administration of phenobarbital. Since montelukast is metabolised by CYP 3A4, 2C8, and 2C9, caution should be exercised, particularly in children, when montelukast is co-administered with inducers of CYP 3A4, 2C8, and 2C9, such as phenytoin, phenobarbital and rifampicin.

In vitro studies have shown that montelukast is a potent inhibitor of CYP 2C8. However, data from a clinical drug-drug interaction study involving montelukast and rosiglitazone (a probe substrate representative of medicinal products primarily metabolized by CYP 2C8) demonstrated that montelukast does not inhibit CYP 2C8 in vivo. Therefore, montelukast is not anticipated to markedly alter the metabolism of medicinal products metabolised by this enzyme (e.g., paclitaxel, rosiglitazone, and repaglinide).

In vitro studies have shown that montelukast is a substrate of CYP 2C8, and to a less significant extent, of 2C9, and 3A4. In a clinical drug-drug interaction study involving montelukast and gemfibrozil (an inhibitor of both CYP 2C8 and 2C9) gemfibrozil increased the systemic exposure of montelukast by 4.4-fold. No routine dosage adjustment of montelukast is required upon co-administration with gemfibrozil or other potent inhibitors of CYP 2C8, but the physician should be aware of the potential for an increase in adverse reactions.

Based on in vitro data, clinically important drug interactions with less potent inhibitors of CYP 2C8 (e.g., trimethoprim) are not anticipated. Co-administration of montelukast with itraconazole, a strong inhibitor of CYP 3A4, resulted in no significant increase in the systemic exposure of montelukast.

4.6. Fertility, pregnancy and lactation

Pregnancy

Animal studies do not indicate harmful effects with respect to effects on pregnancy or embryonal/foetal development.

Available data from published prospective and retrospective cohort studies with montelukast use in pregnant women evaluating major birth defects have not established a drug-associated risk. Available studies have methodologic limitations, including small sample size, in some cases retrospective data collection, and inconsistent comparator groups.

Singulair may be used during pregnancy only if it is considered to be clearly essential.

Breast-feeding

Studies in rats have shown that montelukast is excreted in milk (see section 5.3). It is unknown whether montelukast/metabolites are excreted in human milk.

Singulair may be used in breast-feeding only if it is considered to be clearly essential.

4.7. Effects on ability to drive and use machines

Singulair has no or negligible influence on the ability to drive and use machines. However, individuals have reported drowsiness or dizziness.

4.8. Undesirable effects

Montelukast has been evaluated in clinical studies as follows:

• 10 mg film-coated tablets in approximately 4,000 adult and adolescent asthmatic patients 15 years of age and older.

• 10 mg film-coated tablets in approximately 400 adult and adolescent asthmatic patients with seasonal allergic rhinitis 15 years of age and older.

• 5 mg chewable tablets in approximately 1,750 paediatric asthmatic patients 6 to 14 years of age.

The following drug-related adverse reactions in clinical studies were reported commonly (≥1/100 to <1/10) in asthmatic patients treated with montelukast and at a greater incidence than in patients treated with placebo:

Body System Class

Adult and Adolescent Patients

15 years and older

(two 12-week studies; n=795)

Paediatric Patients

6 to 14 years old

(one 8-week study; n=201)

(two 56-week studies; n=615)

Nervous system disorders

headache

headache

Gastro-intestinal disorders

abdominal pain

With prolonged treatment in clinical trials with a limited number of patients for up to 2 years for adults, and up to 12 months for paediatric patients 6 to 14 years of age, the safety profile did not change.

Tabulated list of Adverse Reactions

Adverse reactions reported in post-marketing use are listed, by System Organ Class and specific Adverse Reactions, in the table below. Frequency Categories were estimated based on relevant clinical trials.

System Organ Class

Adverse Reactions

Frequency Category*

Infections and infestations

upper respiratory infection†

Very Common

Blood and lymphatic system disorders

increased bleeding tendency

Rare

thrombocytopenia

Very Rare

Immune system disorders

hypersensitivity reactions including anaphylaxis

Uncommon

hepatic eosinophilic infiltration

Very Rare

Psychiatric disorders

dream abnormalities including nightmares, insomnia, somnambulism, anxiety, agitation including aggressive behaviour or hostility, depression, psychomotor hyperactivity (including irritability, restlessness, tremor§)

Uncommon

disturbance in attention, memory impairment, tic

Rare

hallucinations, disorientation, suicidal thinking and behaviour (suicidality), obsessive-compulsive symptoms, dysphemia

Very Rare

Nervous system disorders

dizziness, drowsiness, paraesthesia/hypoesthesia, seizure

Uncommon

Cardiac disorders

palpitations

Rare

Respiratory, thoracic and mediastinal disorders

epistaxis

Uncommon

Churg-Strauss Syndrome (CSS) (see section 4.4)

Very Rare

pulmonary eosinophilia

Very Rare

Gastro-intestinal disorders

diarrhoea‡, nausea‡, vomiting‡

Common

dry mouth, dyspepsia

Uncommon

Hepatobiliary disorders

elevated levels of serum transaminases (ALT, AST)

Common

hepatitis (including cholestatic, hepatocellular, and mixed-pattern liver injury).

Very Rare

Skin and subcutaneous tissue disorders

rash‡

Common

bruising, urticaria, pruritus

Uncommon

angiooedema

Rare

erythema nodosum, erythema multiforme

Very Rare

Musculoskeletal and connective tissue disorders

arthralgia, myalgia including muscle cramps

Uncommon

Renal and urinary disorders

enuresis in children

Uncommon

General disorders and administration site conditions

pyrexia‡

Common

asthenia/fatigue, malaise, oedema

Uncommon

*Frequency Category: Defined for each Adverse Reaction by the incidence reported in the clinical trials data base: Very Common (≥1/10), Common (≥1/100 to <1/10), Uncommon (≥1/1,000 to <1/100), Rare (≥1/10,000 to <1/1,000), Very Rare (<1/10,000).

†This adverse experience, reported as Very Common in the patients who received montelukast, was also reported as Very Common in the patients who received placebo in clinical trials.

‡This adverse experience, reported as Common in the patients who received montelukast, was also reported as Common in the patients who received placebo in clinical trials.

§ Frequency Category: Rare

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9. Overdose

In chronic asthma studies, montelukast has been administered at doses up to 200 mg/day to adult patients for 22 weeks and in short term studies, up to 900 mg/day to patients for approximately one week without clinically important adverse experiences.

There have been reports of acute overdose in post-marketing experience and clinical studies with montelukast. These include reports in adults and children with a dose as high as 1,000 mg (approximately 61 mg/kg in a 42 month old child). The clinical and laboratory findings observed were consistent with the safety profile in adults and paediatric patients. There were no adverse experiences in the majority of overdose reports.

Symptoms of overdose

The most frequently occurring adverse experiences were consistent with the safety profile of montelukast and included abdominal pain, somnolence, thirst, headache, vomiting, and psychomotor hyperactivity.

Management of overdose

No specific information is available on the treatment of overdose with montelukast. It is not known whether montelukast is dialysable by peritoneal- or haemodialysis.