Salbutamol

Question 1

Drug class

Answer 1

Beta-adrenergic agonist

Question 2

Pharmacology

Answer 2

Direct acting sympathomimetic agent which mainly affects B2-adrenoceptors. It primarily acts as a bronchodilator but also has inotropic & chronotropic actions. Additionally, it lowers serum potassium levels through its direct stimulation of the sodium/potassium ATPase pump drawing potassium into cells.

Question 3

Metabolism

Answer 3

Hepatic with renal excretion

Question 4

Indications

Answer 4

• Bronchospasm

* Suspected hyperkalaemia (with QRS widening and/or AV dissociation

Question 5

Contraindications

Answer 5

• Allergy and/or adverse drug reaction

* Pts <1yr

Question 6

Precautions

Answer 6

• Acute pulmonary oedema

* Ischaemic heart disease

Question 7

Side effects

Answer 7

• Anxiety
• Tachyarrhythmias
• Tremors
• Hypokalaemia & metabolic acidosis

Question 8

Presentation

Answer 8

• 100mcg/puff metered dose inhaler
• 2.5mg/2.5ml nebule
• 5mg/2.5ml nebule

Question 9

Routes

Onset

Duration

Answer 9

MDI - metered dose inhaler
NEB

2-5min

16-60min

Question 10

Special notes

Answer 10

• COPD pts = 6L/min; all other pts 8L/min

* NEB Salbut will reduce serum potassium by 0.5-1mmol/L within 30mins

Question 11

Adult dosages

Answer 11

Bronchospasm
▪︎ MDI
- 12 (1.2mg) inhalations, repeated at 10mins, no max dose
▪︎ NEB 5mg, PRN, no max dose

Question 12

Paediatric dosages

Answer 12

Bronchospasm
▪︎ NEB
1-5yrs 2.5mg, PRN, no max dose
≥6yrs 5mg, PRN, no max dose