Posology : מינונים

Dosage and Administration

Salbutamol has a duration of action of four to six hours in most patients.

Salbutamol parenteral preparations are to be used under the direction of a physician.

Note: The contents of the ampoules of Salbutamol Solution for intravenous infusion must not be injected undiluted. The concentration should be reduced by 50% before administration.

Salbutamol parenteral preparations should not be administered in the same syringe or infusion as any other medication

Populations

RESPIRATORY
Increasing use of beta-2 agonists may be a sign of worsening asthma. Under these conditions a reassessment of the patient's therapy plan may be required and concomitant glucocorticosteroid therapy should be considered.

•    Adults

In severe Bronchospasm and Status Asthmaticus:

Subcutaneous route: 500mcg (8mcg/kg body weight) and repeated every four hours as required.

Intramuscular route: 500mcg (8mcg/kg body weight) and repeated every four hours as required.

Intravenous route: 250mcg (4mcg/kg body weight) injected slowly. If necessary the dose may be repeated.

If Salbutamol Injection 500mcg in 1ml (0.5mg/ml) is used, the injection may be facilitated by dilution with water for injections BP.

Infusion: In status asthmaticus, infusion rates of 3 to 20mcg/minute are generally adequate, but in patients with respiratory failure, higher dosage has been used with success. A starting dose of 5mcg/minute is recommended with appropriate adjustments in dosage according to patient response.

A suitable solution for infusion may be prepared by diluting 5ml of Salbutamol Solution for intravenous infusion in 500ml of an infusion solution such as Sodium chloride and Dextrose Injection BP to provide a salbutamol dose of 10mcg/ml of solution.

•    Children:

At present there is insufficient evidence to recommend a dosage regimen for routine use in children.



OBSTETRIC

In the Management of Premature Labour

For this indication Salbutamol Solution for intravenous infusion is recommended using a solution prepared as above. It should be administered as early as possible after the diagnosis of premature labour, and after evaluation of the patient to eliminate any contra-indications to the use of salbutamol ( see Contraindications). It is essential that the volume of infusion fluid is kept to a minimum to control the level of hydration and so avoid the risk of maternal pulmonary oedema (see Adverse Reactions). A controlled infusion device, preferably a syringe pump, should be used. Infusion rates of 10-45mcg/minute are generally adequate to control uterine contractions, but greater or less infusion rates may be required according to the strength and frequency of contractions. A starting rate of 10mcg/minute is recommended, increasing the rate at 10-minute intervals until there is evidence of patient response shown by diminution in strength, frequency or duration of contractions .Thereafter the infusion rate may be increased slowly until contractions cease. Careful attention should be given to cardio- respiratory function and fluid balance monitoring. The maternal pulse rate should be monitored and the infusion rate adjusted to avoid excessive maternal heart rates (above 140 beats/minute). Treatment discontinuation should be considered should signs of pulmonary oedema or myocardial ischaemia develop (see Warnings and Precautions and Adverse Reactions).

Once uterine contractions have ceased the infusion rate should be maintained at the same level for one hour and then reduced by 50% decrements at 6-hourly intervals. If labour progresses despite treatment the infusion should be stopped. If contractions have been successfully inhibited by the infusion, treatment may be continued orally with Salbutamol Tablets 4mg given three or four times daily.

Dilution: The recommended diluent is 5% Dextrose ( see precautions for use in diabetic patients).
For use in a syringe pump: Prepare a solution providing 200 micrograms salbutamol/ml by diluting 10ml Ventolin solution for intravenous infusion with 40ml diluent. An infusion rate of 10 to 45 micrograms/minute is equivalent to 0.05 to 0.225 ml/minute of this solution.

As an alternative procedure or to counteract inadvertent overdosage with oxytocic drugs, Salbutamol Injection may be administered as a single injection by the intravenous or intramuscular routes. The usual recommended dose is 100 to 250mcg of Salbutamol. The dose may be repeated according to the response of the patient. Data suggest that the main effect of tocolytic therapy is a delay in delivery of up to 48 hours. This delay may be used to administer glucocorticoids or to implement other measures known to improve perinatal health.