Patients who are prescribed regular anti-inflammatory therapy (e.g., inhaled corticosteroids) should be advised to continue taking their anti-inflammatory medication even when symptoms decrease, and they do not require Salbutamol.
Bronchodilators 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 the patients are at risk of severe attacks and even death. Physicians should consider using oral corticosteroid therapy or the maximum use of inhaled corticosteroids. Increasing use of bronchodilators, particularly short-acting inhaled ß2-agonists to relieve symptoms indicates deteriorating asthma control (especially if the peak expiratory flow rate value falls and/or becomes irregular), and patients should be warned to seek medical advice as soon as possible.
Overuse of short-acting beta-agonists may mask the progression of the underlying disease and contribute to deteriorating asthma control, leading to an increased risk of severe asthma exacerbations and mortality.
Patients who take more than twice a week “as needed” salbutamol, not counting prophylactic use prior to exercise, should be re-evaluated (i.e., daytime symptoms, night-time awakening, and activity limitation due to asthma) for proper treatment adjustment as these patients are at risk for overuse of salbutamol.
In the event of a previous effective dose of inhaled salbutamol failing to give relief for at least three hours or if they need more inhalations than usual, the patient should be advised to seek medical advice as soon as possible. In this situation patients should be reassessed and consideration given to an increase in their anti-inflammatory therapy, (e.g. higher doses of inhaled corticosteroids or a course of oral corticosteroids). A regular anti-inflammatory controller medication taken on a daily basis is required as soon as the patient needs inhaled ß2-agonists more than twice a week. Severe episodes of asthma must be treated in the normal way.
As there may be adverse effects associated with excessive dosing, the dosage and frequency of administration should only be increased on medical advice.
Salbutamol should be administered with caution in patients with thyrotoxicosis, cardiac insufficiency, hypokalaemia, myocardial ischaemia, tachyarrhythmia and hypertrophic obstructive cardiomyopathy.
Potentially serious hypokalaemia may result from ß2 agonist therapy, mainly from parenteral and nebulised therapy. Particular caution is advised in acute severe asthma, as this effect may be potentiated by concomitant treatment with xanthine derivatives, steroids, diuretics and by hypoxia. It is recommended that serum potassium levels are monitored in such situations (see section 4.5).
Rarely inhalation therapy may cause bronchospasm after dosing. In this event, treatment with Salbutamol must be immediately discontinued and, if need be, replaced with another therapy.
Cardiovascular effects may be seen with sympathomimetic drugs, including salbutamol. There is some evidence from post-marketing data and published literature of rare occurrences of myocardial ischaemia associated with salbutamol. Patients with underlying severe heart disease (e.g. ischaemic heart disease, arrhythmia or severe heart failure) who are receiving salbutamol should be warned to seek medical advice if they experience chest pain or other symptoms of worsening heart disease. Attention should be paid to assessment of symptoms such as dyspnoea and chest pain, as they may be of either respiratory or cardiac origin.
In common with other beta-adrenoceptor agonists, salbutamol can induce reversible metabolic changes such as increased blood glucose levels. Diabetic patients may be unable to compensate for the increase in blood glucose and the development of ketoacidosis has been reported. Concurrent administration of glucocorticoids can exaggerate this effect.
One dose contains less than 10 mg lactose, which probably does not cause symptoms in lactose intolerant patients. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.