Salbutamol is a selective β-2 adrenoceptor agonist. It has very little or no action on the β-1 receptors of the heart. At therapeutic doses, salbutamol acts on the β-2 receptors of the bronchial muscle, the end effect being dilation of the bronchial airways through relaxation of bronchial smooth muscle and reduction of airway resistance.
Salbutamol is indicated for the relief of bronchospasm in bronchial asthma of all types, chronic bronchitis and emphysema.
Dosage and administration
In most patients, salbutamol has a duration of action of 4-6 hours
Adults and children over 12 years: one to two 5ml spoonful three to four times a day.
Children 6-12 years: one 5ml spoonful three to four times a day
Children 2-6 years: Half to one 5ml spoonful three to four times a day.
Adults and children over 12 years: one to two tablets three to four times a day
Adults and children over 12 years: half to one tablet three to four times a day.
Patients with a history of hypersensitivity to any of the constituents. Although, salbutamol tablets may occasionally be used for management of premature labour complicated by conditions such as placenta praevia or ante-partum haemorrhage or toxaemia of pregnancy, they should NOT be used for threatened abortion.
Bronchodilators, like salbutamol, should not be the only or main treatment in patients with severe or unstable asthma. Severe asthma requires regular medical assessment, including lung function testing, as risk of severe attacks and even death are high. Oral and/or inhaled corticosteroid therapy should therefore also be used in conjunction with salbutamol in such patients.
Increased use/dosage to control symptoms, indicates deterioration of asthma control. Therefore, if the usual relief or duration of action is reduced, medical advice should be immediately sought.
Salbutamol should be used with caution in patients with thyrotoxicosis. In acute severe asthma, serum potassium levels should be monitored. This is because potentially serious hypokalaemia may result from concurrent use of salbutamol and xanthine derivatives, steroids and diuretics
Salbutamol and non-selective beta-blocking drugs, such as propranolol, should not be given/prescribed together.
Pregnancy and lactation
As with most medications, salbutamol should only be used in pregnancy when very clearly needed and when the potential benefits to the mother, outweighs the risks to the foetus.
Salbutamol is secreted in breast milk. It is not known whether salbutamol in breast milk has a harmful effect on the neonate.
Nevertheless, it is recommended that the use of salbutamol in nursing mothers be avoided, unless the expected benefits outweighs the risks.
Fine tremor of skeletal muscle, headache, peripheral vasodilation and a feeling of tension have been reported, fairly frequently.
Hypersensitivity reactions such as angioedema, urticarial, bronchospasm, hypotension and collapse are very rare side effects.
Hypokalaemia may occur following overdose with salbutamol. Serum potassium levels should therefore be monitored. A cardioselective beta-antagonist is the preferred antidote.