The effect of different nebulizers with and without intermittent positive pressure breathing on the absorption and metabolism of salbutamol.

1 The absorption and metabolism of [(3)H]-salbutamol have been studied to assess whether intermittent positive pressure breathing (IPPB) or a particular nebulizer have any advantages in delivering bronchodilator drugs to asthmatic patients. 2 [(3)H]-salbutamol (10 mg) was given to asthmatic patients from either the Bird Mark 7 ventilator without intermittent positive pressure, the Bird micronebulizer attached to an electric air compressor, or the Wright's nebulizer attached to the same compressor. 3 All patients showed a high early plasma level of radioactivity due mainly to free salbutamol. This pattern suggests absorption from the lung and is similar to that seen after giving the drug from the Bird nebulizer using IPPB. 4 In all cases less than 20% of the original dose was absorbed by the patient. 5 Improvement in forced expiratory volume in one second (FEV(1)) was seen with all three treatments.