Study Supports NIH Guidelines for Spacer Use in Asthma Drug Delivery

In a study to assess drug deposition and distribution of an inhaled asthma medication, researchers at Case Western Reserve University, University Hospitals of Cleveland, and Rhone-Poulenc Rorer Pharmaceuticals demonstrated that use of the Azmacort (triamcinolone acetonide) built-in spacer, a device designed to enhance drug delivery and minimize local side effects, increased drug delivery to the lungs 180% over drug delivery without the spacer.

The researchers measured drug deposition with advanced positron emission tomography (PET), a non-invasive imaging technology that produces powerful images of the human body's metabolic activity and biological functions. PET has previously been used in diagnostic areas including oncology, cardiology and neurology, in the detection of disease and to measure the effectiveness of therapies to treat disease. The Azmacort study marks the first use of PET technology to provide a quantitative measure of drug deposition of an inhaled medication by area and amount in the body.

Last year, the National Institutes of Health (NIH) released updated guidelines for the diagnosis and management of asthma. In those guidelines, NIH recommended spacer use with inhaled corticosteroids to improve inhalation technique and reduce local side effects.

A spacer is a chamber through which medication is released. The chamber reduces the velocity of released medication, providing a more gentle mist of suspended particles. The suspended particles have an optimized particle size distribution, which targets medication to the lungs, decreases drug deposition in the mouth (lowering the incidence of local side effects), and improves coordination of inhalation technique.

When comparing drug deposition of triamcinolone acetonide with the use of Azmacort's built-in spacer versus drug deposition without a spacer, researchers found on average a 180% increase in lung deposition as well as 333%, 142% and 113% increases in drug deposition to the central, intermediate and peripheral regions of the lungs, respectively.

Researchers also found a 22% decrease in oropharyngeal (mouth and throat) deposition based on actual dose delivered, and a 41% decrease in mouth and throat deposition based on amount of drug leaving the Azmacort canister.

For more information: Lise Geduldig, Rhone-Poulenc Rorer, 500 Arcola Road, PO Box 1200, Collegeville, PA 19426-0107. Tel: 610-454-2735.

Edited by Beth Brindle