The effect of physiological manoeuvres on the absorption of inhaled nedocromil sodium.

In a previous study we showed, in both asthmatic patients and in healthy subjects, a marked increase in plasma concentration of nedocromil immediately following an exercise challenge with associated FEV1 measurements. To identify which component of the exercise challenge is responsible, we have now studied the effect of various manoeuvres on plasma nedocromil concentration in eight healthy subjects after inhalation of 1 ml nedocromil solution (1% w/v) via a Wright nebuliser. Each patient was dosed on six occasions, separated by at least 3 days. Between 15 and 23 min after dosing one of the following manoeuvres was performed: control (no manoeuvre); steady exercise for 8 min, a series of FEV1 measurements, exercise plus FEV1 measurements, three Valsalva manoeuvres and hyperventilation for 3 min. Mean plasma drug concentrations under control conditions were similar at 15 and 23 min after dosing. However, there were significant increases in plasma drug concentration following exercise, FEV1 manoeuvres and exercise plus FEV1 manoeuvre. There were no significant changes in plasma drug concentration following Valsalva manoeuvres and hyperventilation. The results suggest that certain manoeuvres increase the absorption of nedocromil sodium, probably as a consequence of an increase in lung volume.

RCT Entities:   Population Interventions Outcomes