Salbutamol inhaler is indicated in adults, adolescents and children aged 4 to 11 years.It provides short-acting (4 to 6 hour) bronchodilation with fast onset (within 5 minutes) in reversible airways obstruction. It is particularly suitable for the relief and prevention of asthma symptoms. It should be used to relieve symptoms when they occur, and to prevent them in those circumstances recognized by the patient to precipitate an asthma attack (e.g. before exercise or unavoidable allergen exposure)
Salbutamol inhaler is particularly valuable as relief medication in mild, moderate or severe asthma, provided that the reliance on it does not delay the introduction and use of regular inhaled corticosteroid therapy.
Relief of acute bronchospasm
The usual dosage for children under the age of 12 years: one inhalation (100 micrograms). The dose may be increased to two inhalations if required. Children aged 12 years and over dose as per adult population.
Prevention of allergen or exercise-induced bronchospasm
The usual dosage for children under the age of 12: one inhalation (100 micrograms) before challenge or exertion. The dose may be increased to two inhalations if required.
Children aged 12 years and over: dose as per adult population.
The usual dosage for children under the age of 12 years: up to two inhalation 4 times daily.
Children aged 12 years and over: dose as per adult population. The infant spacer device may be used to facilitate administration to children under 5 years of age.
On-demand use of salbutamol inhaler should not exceed 8 inhalations in any 24 hours. Reliance on such frequent supplementary use, or a sudden increase in dose, indicates poorly controlled or deteriorating asthma.
Although intravenous salbutamol, and occasionally salbutamol tablets are used in the management of premature labour uncomplicated by conditions such as placenta praevia, ante-partum haemorrhage or toxaemia of pregnancy, inhaled salbutamol preparations are not appropriate for managing premature labour. Salbutamol preparations should not be used for threatened abortion. Salbutamol inhaler is contraindicated in patients with a history of hypersensitivity to any of the components.
Interaction with other medicinal products and other forms of interaction
Salbutamol and non-selective β-blocking drugs such as propranolol, should not usually be prescribed together.
Pregnancy and lactation
Studies in animals have shown reproductive toxicity. Safety in pregnant women has not been established. Not controlled clinical trials with salbutamol have been conducted in pregnant women. Rare reports of various congenital anomalies following intrauterine exposure to salbutamol (including cleft palate, limb defects and cardiac disorders) have been received. Some of the mothers were taking multiple medications during their pregnancies. Salbutamol inhaler should not be used during pregnancy unless clearly necessary.
As salbutamol is probably secreted in breast milk, its use in nursing mothers requires careful consideration. It is not known whether salbutamol has a harmful effect on the neonate, and so its use should be restricted to situations where it is felt that the expected benefit to the mother is likely to outweigh any potential risk to the neonate.
Effects on ability to drive and use machines
Immune system disorders: hypersensitivity reactions including angioedema, urticarial, bronchospasm, hypotension and collapse
Metabolism and nutrition disorders: hypokalaemia, potentially serious hypokalaemia may result from beta2 agonist therapy
Nervous system disorders: tremor, headache, hyperactivity
Cardiac disorders: tachycardia, palpitations, cardiac arrhythmias
Gastrointestinal disorders: mouth and throat irritation
Respiratory, thoracic and mediastinal disorders: paradoxical bronchospasm.
As with other inhalation therapy, paradoxical bronchospasm may occur with an immediate increase in wheezing after dosing. This should be treated immediately with an alternative presentation or a different fast-acting inhaled bronchodilator. Inhaler should be discontinued immediately, the patient assessed and if necessary, alternative therapy instituted.
Salbutamol is a selective β2 adrenoceptor agonist. At therapeutic doses it acts on the β2-adrenoceptors of bronchial muscle providing short acting (4-6 hour) bronchodilation with a fast onset (within 5 minutes) in reversible airways obstruction.
After administration by the inhaled route between 10 and 20% of the dose reaches the lower airways. The remainder is retained in the delivery system or is deposited in the oropharynx from where it is swallowed. The fraction deposited in the airways is absorbed into the pulmonary tissues and circulation, but is not metabolized by the lung.
On reaching the systematic circulation it becomes accessible to hepatic metabolism and is excreted, primarily in the urine, as unchanged drug as the phenolic sulphate. The swallowed portion of an inhaled dose is absorbed from the gastrointestinal tract and undergoes considerable first-pass metabolism to the phenolic sulphate.
Both unchanged drug and conjugate are excreted primarily in the urine. Most of a dose of salbutamol given intravenously, orally or by inhalation is excreted within 72 hours. Salbutamol is bound to plasma proteins to the extent of 10%