There is limited clinical experience on the management of overdose.
Symptoms
An overdose would likely lead to effects that are typical of β2-agonists: tremor, headache, palpitations. Symptoms reported from isolated cases are tachycardia, hyperglycaemia, hypokalaemia, prolonged QTc-interval, arrhythmia, nausea and vomiting. Supportive and symptomatic treatment is indicated.
Management
Use of cardioselective beta-blockers may be considered, but only subject to extreme caution since the use of β-adrenergic blocker medication may provoke bronchospasm. Serum potassium should be monitored.
Not applicable.
Summary of the safety profile
The most commonly reported adverse events of β2-agonist therapy, such as tremor and palpitations, tend to be mild and disappear within a few days of treatment.
Tabulated list of adverse reactions
Adverse reactions, which have been associated with formoterol are given below, listed by system organ class and frequency. Frequency are defined as: very common (>1/10), common (>1/100 and <1/10), uncommon (>1/1 000 and <1/100), rare (>1/10 000 and <1/1000) and very rare <1/10 000).
| System Organ Class | Frequency | Adverse Reaction |
| Cardiac disorders | Uncommon | Palpitations |
| Uncommon | Tachycardia | |
| Uncommon | Cardiac arrhythmias, e.g. atrial fibrillation, supraventricular tachycardia, extrasystoles. | |
| Uncommon | Angina pectoris | |
| Very rare | Prolongation of QTc interval | |
| Gastrointestinal disorders | Common | Nausea |
| Immune system disorders | Uncommon | Hypersensitivity reactions, e.g. bronchospasm, exanthema, urticaria, pruritus |
| Metabolic and nutrition disorders | Uncommon | Hypokalaemia |
| Uncommon | Hyperglycaemia | |
| Musculoskeletal, connective tissue and bone disorders | Common | Muscle cramps |
| Nervous system disorders | Common | Headache*, tremor, dizziness |
| Uncommon | Taste disturbances | |
| Psychiatric disorders | Uncommon | Sleep disturbances |
| Rare | Agitation, restlessness | |
| Vascular disorders | Uncommon | Variations in blood pressure |
* Headache occurred in 6.5% of patients in OXIS and 6.2% on placebo.
Description of selected adverse reactions
As with all inhalation therapy, paradoxical bronchospasm may occur in very rare cases.
Treatment with β2-agonists may result in an increase in blood levels of insulin, free fatty acids, glycerol and ketone bodies.
The excipient lactose contains small amounts of milk proteins. These may cause allergic reactions.
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, Website: www.mhra.gov.uk/yellowcard
The effects of formoterol seen in toxicity studies in rats and dogs were mainly on the cardiovascular system and consisted of hyperaemia, tachycardia, arrhythmias and myocardial lesions. These effects are known pharmacological manifestations seen after the administration of high doses of β2-agonists.
No genotoxic effects of formoterol have been observed in in-vitro or in vivo tests. In rats and mice a slight increase in the incidence of benign uterine leiomyomas has been observed. This effect is looked upon as a class-effect observed in rodents after long exposure to high doses of β2-agonists.
Duaklir Genuair (Formoterol) is indicated in adults, adolescents and children aged 6 years and older, as add on therapy to maintenance treatment with inhaled corticosteroids, for the relief of broncho-obstructive symptoms and prevention of exercise-induced symptoms, in patients with asthma when adequate treatment with corticosteroids is not sufficient.
Duaklir Genuair (Formoterol) is also indicated in adults for the relief of broncho-obstructive symptoms in patients with chronic obstructive pulmonary disease (COPD).
Pharmacotherapeutic group: selective β2-agonist, formoterol, ATC code: R03A C13.
Mechanism of action and pharmacodynamic effects
Formoterol is a selective β2-adrenoceptor agonist that produces relaxation of bronchial smooth muscle. Formoterol thus has a bronchodilating effect in patients with reversible airways obstruction. The bronchodilating effect sets in rapidly, within 1-3 minutes after inhalation and has a mean duration of 12 hours after a single dose.
Absorption
Inhaled formoterol is rapidly absorbed. Peak plasma concentration is reached about 10 minutes after inhalation.
In a pharmacokinetic study, the mean lung deposition of formoterol after inhalation via Turbohaler was 43% of the delivered dose. The total systemic availability was around 60% of the delivered dose.
Distribution and biotransformation
Plasma protein binding is approximately 50%.
Formoterol is metabolised via direct glucuronidation and O-demethylation. The enzyme responsible for O-demethylation has not been identified.
Elimination
The major part of the dose of formoterol is eliminated via metabolism. Total plasma clearance and volume of distribution has not been determined. After inhalation 8-13% of the delivered dose of formoterol is excreted unmetabolised in the urine. About 20% of an intravenous dose is excreted unchanged in the urine. The terminal half-life after inhalation is estimated to be 17 hours.
Linearity/non-linearity
Systemic exposure for formoterol correlates in a linear fashion to administered dose.
Special populations
The effect of decreased liver or kidney function on the pharmacokinetics of formoterol and the pharmacokinetics in the elderly is not known. As formoterol is primarily eliminated via liver metabolism an increased exposure can be expected in patients with severe liver cirrhosis.
General
Duaklir Genuair (Formoterol) should not be used (and is not sufficient) as the first treatment for asthma.
Asthmatic patients who require therapy with long acting β2-agonists, should also receive optimal maintenance anti-inflammatory therapy with corticosteroids. Patients must be advised to continue taking their anti-inflammatory therapy after the introduction of Duaklir Genuair (Formoterol) even when symptoms decrease. Should symptoms persist, or treatment with β2-agonists need to be increased, this indicates a worsening of the underlying condition and warrants a reassessment of the maintenance therapy.
Although Duaklir Genuair (Formoterol) may be introduced as add-on therapy when inhaled corticosteroids do not provide adequate control of asthma symptoms, patients should not be initiated on Duaklir Genuair (Formoterol) during an acute severe asthma exacerbation, or if they have significantly worsening or acutely deteriorating asthma. Serious asthma-related adverse events and exacerbations may occur during treatment with Duaklir Genuair (Formoterol). Patients should be asked to continue treatment but to seek medical advice if asthma symptoms remain uncontrolled or worsen after initiation on Duaklir Genuair (Formoterol). Once asthma symptoms are controlled, consideration may be given to gradually reducing the dose of Duaklir Genuair (Formoterol). Regular review of patients as treatment is stepped down is important. The lowest effective dose of Duaklir Genuair (Formoterol) should be used.
The maximum daily dose should not be exceeded. The long-term safety of regular treatment at higher doses than 36 micrograms per day in adults with asthma, 18 micrograms per day in children with asthma and 18 micrograms per day in patients with COPD, has not been established.
Frequent need of medication (i.e. prophylactic treatment e.g. corticosteroids and long-acting β2-agonists)for the prevention of exercise-induced bronchoconstriction several times every week, despite an adequate maintenance treatment, can be a sign of suboptimal asthma control, and warrants a reassessment of the asthma therapy and an evaluation of the compliance.
Cardiovascular and endocrine disorders
Caution should be observed when treating patients with thyrotoxicosis, phaeochromocytoma, hypertrophic obstructive cardiomyopathy, idiopathic subvalvular aortic stenosis, severe hypertension, aneurysm or other severe cardiovascular disorders, such as ischaemic heart disease, tachyarrhythmias or severe heart failure.
QTc prolongation
Formoterol may induce prolongation of the QTc-interval. Caution should be observed when treating patients with prolongation of the QTc-interval and in patients treated with drugs affecting the QTc-interval.
Diabetic patients
Due to the hyperglycaemic effects of β2-agonists, additional blood glucose monitoring is recommended initially in diabetic patients.
Hypokalaemia
Potentially serious hypokalaemia may result from β2-agonist therapy. Particular caution is recommended in acute severe asthma as the associated risk may be augmented by hypoxia. The hypokalaemic effect may be potentiated by concomitant treatment with xanthine-derivatives, steroids and diuretics. The serum potassium levels should therefore be monitored.
Bronchospasm
As with other inhalation therapy, the potential for paradoxical bronchospasm should be considered. If it occurs, the treatment should be discontinued immediately and alternative therapy started.
Lactose intolerance
Duaklir Genuair (Formoterol) contains lactose monohydrate 891 micrograms per delivered dose. This amount does not normally cause problems in lactose intolerant people. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Paediatric population
Children up to the age of 6 years should not be treated with Duaklir Genuair (Formoterol), as no sufficient experience is available for this group.
Duaklir Genuair (Formoterol) has no or negligible influence on the ability to drive and use machines.
Posology
Use of doses above those normally required by the individual patient on more than 2 days per week, is a sign of suboptimal disease control and maintenance treatment should be reassessed.
Asthma:In asthma, Duaklir Genuair (Formoterol) can be used once or twice daily ('regular dosage') and as 'relief medication' to relieve acute broncho-obstructive symptoms.
Adults aged > 18 years:
Relief medication: 1 inhalation for the relief of acute broncho-obstructive symptoms.
Regular dosage: 1 inhalation once or twice daily. Some patients may need 2 inhalations once or twice daily.
Prevention of exercise-induced bronchoconstriction: 1 inhalation before exercise.
The daily dose for regular use should not exceed 4 inhalations, however occasionally up to a maximum of 6 inhalations may be allowed within a 24-hour period. No more than 3 inhalations should be taken on any single occasion.
Children and adolescents 6 years and older:
Relief medication: 1 inhalation for the relief of acute broncho-obstructive symptoms.
Regular dosage: 1 inhalation once or twice daily.
Prevention of exercise-induced bronchoconstriction: 1 inhalation before exercise.
The regular daily dose should not exceed 2 inhalations, however, occasionally up to a maximum of 4 inhalations may be allowed within a 24-hour period. No more than 1 inhalation should be taken on any single occasion.
COPD:
Adults aged > 18 years:
Regular dosage: 1 inhalation once or twice daily.
The daily dose for regular use should not exceed 2 inhalations.
If required, additional inhalations above those prescribed for regular therapy may be used for relief of symptoms, up to a maximum total daily dose of 4 inhalations (regular plus as required). More than 2 inhalations should not be taken on any single occasion.
Special populations:
Elderly
There are no special dosing requirements for elderly patients.
Patients with hepatic or renal impairment:
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Paediatric population:
Duaklir Genuair (Formoterol) is not recommended for use in children below 6 years due to insufficient data on safety and efficacy.
NB! A lower strength (6 micrograms/dose) is also available.
Method of administration
Instructions for correct use of Duaklir Genuair (Formoterol)
Duaklir Genuair (Formoterol) is inspiratory flow driven which means that, when the patient inhales through the mouthpiece, the substance will follow the inspired air into the airways.
Note! It is important to instruct the patient to breathe in forcefully and deeply through the mouthpiece to ensure that an optimal dose is obtained.
It is important to instruct the patient never to chew or bite on the mouthpiece and never to use the inhaler if it has been damaged or if the mouthpiece has become detached.
The patient may not taste or feel any medication when using Duaklir Genuair (Formoterol) due to the small amount of drug dispensed.
Detailed instructions for use are packed together with each inhaler.
No special requirements.
