Salbutamol is a synthetic sympathomimetic agent with predominant beta-2 adrenergic activity. Salbutamol produces bronchodilatation through stimulation of beta-2-adrenergic receptors in bronchial smooth muscles, thereby causing relaxation of bronchial muscle fibers. This action is manifested by an improvement in pulmonary function as demonstrated by spirometric measurements.

Salbutamol is indicated as a bronchodilator for use in-

• Asthma
• Chronic Bronchitis
• Emphysema and
• Other conditions associated with airways obstruction.

Salbutamol tablet or syrup-

Children:

• 2-6 years: 2.5 ml syrup, 3-4 times daily
• 6-12 years: 5 ml syrup, 3-4 times daily
• Over 12 years: 5-10 ml syrup, 3-4 times daily (2-4 mg tablet, 3-4 times daily)

Adults: 2-4 mg tablet, 3-4 times daily. Maximum single dose is 8 mg tablet.

Salbutamol Respirator Solution: To be used with a suitable nebulizer device under the direction of a physician. The solution must not be injected or ingested.

Method-1 (Intermittent Administration):

• Adults (and the elderly): 0.5 ml-1.0 ml salbutamol up to four times a day. Up to 40mg per day can be given under strict medical direction in the hospital. 0.5-1 ml solution should be diluted to final volume of 2-4 ml with sterile normal saline solution. It will take time about 10 minutes.
• Salbutamol respiratory solution may be used undiluted for intermittent administration. For this 2.0 ml of the solution is placed in the nebulizer and the patient allowed to inhale until bronchodilation is achieved. This usually takes 3-5 minutes.
• Children under 12 years of age: 0.5 ml of the solution diluted to 2.0-4.0 ml with normal saline. Some children may however require higher doses of up to 1.0 ml of the solution. Intermittent treatment may be repeated four times a day.

Method-2 (Continuous administration): 1-2 ml solution is diluted to make up to 100 ml with normal saline solution. The diluted solution is administered by a suitable nebulizer devise. When there is risk of anoxia through hypoventilation, oxygen should be added to the inspired air.

Salbutamol nebulizer solution: To be used with a suitable nebulizer device under the direction of a physician. The solution must not be injected or ingested.

• Adults & Elderly: 2.5 mg to 5 mg Salbutamol up to 4 times a day. Up to 40 mg/day may be given under strict medical direction in the hospital.
• Children under 12 years: 2.5 mg up to 4 times a day. A higher dose up to 5 mg four times a day may be used if required.

Salbutamol injection:

Adults:

• Salbutamol I.V. infusion solution is used to prepare a solution for continuous intravenous infusion. It should not be injected undiluted. A suitable solution for infusion may be prepared by diluting 5 mL of Salbutamol I.V. infusion solution (1000 mcg/mL) in 500 mL of a chosen i.v. solution to provide a salbutamol concentration of 10 mcg/mL.
• The only recommended diluents are Sodium Chloride Injection, or Sodium Chloride and Dextrose Injection.
• Infusion rates providing 3 to 20 micrograms salbutamol/minute (0.3 to 2ml/minute of the above infusion solution) are usually adequate. Infusion rates can be started at 5 mcg of salbutamol/min., and can be increased to 10 mcg/min., and 20 mcg/min. at 15 - 30 minute intervals, if necessary.
• As with all parenteral drug products, intravenous admixtures should be inspected visually for clarity, particulate matter, precipitate, discoloration and leakage prior to administration.
• All unused admixtures of Salbutamol infusion solution with infusion fluids should be discarded 24 hours after preparation.

Children and Adolescents (<18 years of age): The dosage of Salbutamol infusion solution in the pediatric age group has not been established. At present, there are insufficient data to recommend a dosage regimen for children.

Salbutamol Inhalation Capsule:

• Adults: For the relief of bronchospasm and for managing intermittent episodes of asthma, one or two inhalation capsule may be administered as a single dose. The usual recommended dosage of Salbutamol inhalation capsule for inhalation for adults for maintenance or prophylactic therapy is the contents of one 200 microgram capsule every 4 to 6 hours using a device. In some patients, the contents of two 200 microgram capsules inhaled every 4 to 6 hours may be required. Large doses or more frequent administration is not recommended. The use of salbutamol powder for inhalation can be continued as medically indicated to control recurring/intermittent episodes of bronchospasm.
• Children: One Salbutamol inhalation capsule is the recommended dose for relief of acute bronchospasm in the maintenance of episodic asthma or before exercise of children 4 years of age and older. One inhalation should be administered for three or four times a day for routine maintenance or prophylactic therapy. This dosage may be increased to inhalation of two inhalation capsule, if necessary. The bronchodilator effect of each administration of inhaled Salbutamol inhalation capsule lasts for at least four hours. Such patients should be warned not to increase the dose of inhaler, but should seek medical advice immediately.

Excercise-induced Asthma:

• Adults: 400 microgram
• Child: 200 microgram, 15-30 minutes prior to any physical exertion.

Salbutamol may cause fine tremor of skeletal muscles (particularly the hands), palpitations and muscle cramps. Tachycardia, tenseness, headaches and peripheral vasodilatation have been reported after large doses.

Overdose Effects

The symptoms with overdosage are angina, headache, nausea, vomiting, tremor etc. The preferred antidote for overdosage with Salbutamol is a cardio-selective beta-blocking agent but beta-blocking drugs should be used with caution in patients with a history of bronchospasm.

Salbutamol should be used with caution in patients with hyperthyroidism, cardiovascular disease, occlusive vascular disorders, hypertension and aneurysms. Hypokalaemia associated with high doses of Salbutamol may result in increased susceptibility to digitalis-induced cardiac arrhythmia. Tachyphylaxis with resistance may occur with prolonged use of high dosage. Care is necessary when treating patients with diabetes mellitus or closed angle glaucoma, and in those receiving antihypertensive therapy.

Pregnancy & Lactation

The drug should be used during pregnancy only if the potential benefit justifies the potential risk of the fetus. It is not known whether this drug is excreted in human milk. Because of the potential of tumorigenecity shown for Salbutamol in some animal studies, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.