Comparing Bronchodilation of Symbicort With and Without Valved Holding Chamber (Aerochamber Plus)

A Comparison of the Bronchodilating Activity of Symbicort Pressure Metered Dose Inhaler (pMDI) 160/4.5 Used in the Conventional Manner and With a Valved Spacer Holding Chamber (Aerochamber Plus)

This study will compare the amount of bronchial tube relaxation from the Formoterol medicine contained in the Symbicort pressure Metered Dose Inhaler(pMDI)(a combination of Budesonide, a steroid, and Formoterol, a drug which relaxes the bronchial smooth muscle. The comparison will be using the pMDI in the usual fashion to the pMDIs and a spacer which allows more time for breathing in the medication. Breathing tests will be measured over a 12 hour period for the comparison.

Sixteen subjects will receive treatment in a cross-over design. They will inhale Symbicort 160/4.5 two inhalations in the manner prescribed in the approved package insert. The second intervention will be the inhalation of Symbicort 160/4.5 two inhalations through a valved holding chamber (Aero Chamber Plus). Breathing tests including spirometry will be measured at various time periods over a 12-hour time frame in each intervention. Comparison will be made of the two periods to demonstrate that the use of the valved holding chamber does not adversely affect the bronchodilation of the formoterol component of the combination drug.

Inclusion Criteria:

• Asthma with 15% or more increase in Forced expiratory volume at 1 second (FEV-1) after 180-360 mcg of albuterol pMDI

Exclusion Criteria:

• Any illness or condition which might place subject at risk in the study;e.g. some cardiovascular disorders Inability to understand and sign informed consent