Oral Salbutamol and Acute Exacerbation of Airway Obstruction

The management principles of asthma are well established and the subject of numerous readily available clinical practice guidelines. First-line symptomatic treatment is short-acting, inhaled ß2-agonists (SABAs), such as salbutamol or terbutaline.2In Australia, salbutamol is available in various forms, including pressurised, metered-dose inhalers, nebuliser solution, intravenous solution and a syrup for oral administration.3

Most current guidelines recommend the use of salbutamol by metered-dose inhaler via a spacer in the treatment of mild, moderate and severe acute asthma. Nebulised salbutamol is indicated in critical, life-threatening presentations.2

Outcomes for children with acute asthma in the community or hospital setting are no worse for salbutamol delivered via a spacer than nebulised salbutamol. In fact, outcomes for salbutamol delivered via a spacer are favourable in terms of limiting time in the emergency department and minimising side effects.4 Spacers are now widely used in the community. They are inexpensive, portable and easy to maintain.

There is minimal evidence to support the use of oral salbutamol for the management of asthma in developed countries. The practice is specifically – and increasingly strongly – discouraged in a number of guidelines (Box 1). Additionally, there is no evidence for any benefit in bronchiolitis5 or acute cough.6

Box 1. Specific reference to oral ß-agonist administration in recent asthma guidelines

Australia, 200613	‘Oral therapy with SABAs is discouraged in all age groups due to a slower onset of action and the higher incidence of behavioural side effects and sleep disturbance. It may have a limited role in the treatment of children under 2–3 years of age with mild occasional asthma.’
Australia, 20142	‘Oral short-acting ß2 agonists are associated with adverse effects and should not be used in any age group.’
New Zealand, 200514	‘Oral ß2-agonists for treatment of asthma symptoms should be discouraged in all age groups because the onset of action is slow (30–60 minutes), they are relatively ineffective, and the incidence of behavioural side-effects and sleep disturbance is relatively high.’
Malaysia, 201415	‘Routine oral bronchodilator use is discouraged due to its narrow therapeutic index and erratic gastrointestinal absorption resulting in variable and inconsistent efficacy.’
Global Initiative for Asthma (GINA), 201416	‘Oral bronchodilator therapy is not recommended due to its slower onset of action and higher rate of side-effects compared with inhaled SABA.’
Singapore, 200817	‘Inhaled bronchodilators are preferred as they have quicker onset of action and fewer side effects than oral or IV administration.’ ‘Oral therapy is seldom required as most children are able to use inhaler therapy with the appropriate spacer device.’
British Thoracic Society/Scottish Intercollegiate Guidelines Network, 201418	‘Oral ß2 agonists are not recommended for acute asthma in infants.’

Oral salbutamol preparations lead to a slower bronchodilator response than inhaled salbutamol.9 They also pose the risk of unintentional ingestion by young children. Although most ingestions are benign, potential complications include hypokalaemia, hypoglycaemia, restlessness and tachycardia.10

Despite recommendations against the use of oral bronchodilators in developed countries, the World Health Organization (WHO) has been reluctant to delete oral salbutamol from its list of essential medicines.11 Reasons for continued use – particularly in resource-poor settings – include:

• non-availability and relatively high cost of inhaled dosage forms
• ease of use of oral medication
• improved compliance9
• perceived social stigma of using inhalers
• lack of time and resources to enable patient education regarding inhaler technique.12

In Malaysia:

1. Formulari Ubat Kementerian Kesihatan Malaysia stated that:

Generic Name	Cate-gory	Indication(s)	Dosage
Salbutamol 2 mg Tablet	B	Asthma and other conditions associated with reversible airways obstruction	CHILD 2 - 6 years : 1 - 2 mg 3 - 4 times daily, 6 - 12 years : 2 mg 3 - 4 times daily. CHILD over 12 years and ADULT : 2 - 4 mg 3 - 4 times daily
Salbutamol 2 mg/5 ml Syrup	B		CHILD 2 - 6 years : 1 - 2 mg 3 - 4 times daily, 6 - 12 years : 2 mg 3 -4 times daily

2. Paediatric Protocols for Malaysian Hospitals (4th Edition) stated that oral salbutamol has no role  during acute asthma attack, acute bronchiolitis and croup.

For any usage of medication outside the FUKKM indication and Malaysia Paediatric Protocols recommendation (e.g. below two years old), the responsibility lies solely on the prescriber.

References:

* https://www.racgp.org.au/afp/2016/april/it-is-time-to-stop-prescribing-oral-salbutamol/

* FUKKM [online]: Accessed on 15 July 2019