Salbutamol has a duration of action of 4-6 hrs in most patients.
Increasing use of beta2-agonists may be a sign of worsening asthma. Under these conditions, a re-assessment of the patient's therapy plan may be required and concomitant glucocorticosteroid therapy should be considered. As there may be adverse effects associated with excessive dosing, the dosage or frequency of administration should only be increased on medical advice.
Tablet/Syrup: Adults: The usual effective dose is 4 mg (two 2-mg tabs or 10 mL of syrup) 3 or 4 times/day. If adequate bronchodilation is not obtained, each single dose may be gradually increased to as much as 8 mg or 20 mL of syrup.
Some patients obtain adequate relief with 5 ml of syrup (2 mg salbutamol) 3 or 4 times daily.
Children >12 years: 2-4 mg as one to two 2-mg tab or 5-10 mL of syrup; 6-12 years: 2 mg as one 2-mg tab or 5 mL of syrup; 2-6 years: 1-2 mg as half to one 2-mg tab or 2.5-5 mL of syrup. All doses should be administered 3 or 4 times daily.
Special patient groups: In elderly patients or in those known to be unusually sensitive to beta- adrenergic stimulant drugs, it is advisable to initiate treatment with 5 ml of syrup (2 mg salbutamol) 3 or 4 times per day.