Copyright ©ERS Journals Ltd 2003 Distribution of technetium-99m-labelled QVARTM delivered using an AutohalerTM device in children1 Dept of Paediatrics, University of Western Australia, and Depts of 2 Respiratory Medicine and 3 Nuclear Medicine, Princess Margaret Hospital for Children CORRESPONDENCE: S.G. Devadason, University Dept of Paediatrics, Princess Margaret Hospital for Children, Roberts Road, Subiaco WA 6008, Australia. Fax: 61 893882097. E-mail: sunalene@paed.uwa.edu.au Keywords: aerosol delivery to children, lung deposition, paediatric asthma therapy
Received: September 24, 2002
This study was funded, in part, by 3M Pharmaceuticals Pty Ltd, Sydney, Australia. S.G. Devadason was supported by a grant from the National Health and Medical Research Council of Australia.
QVARTM, an extrafine hydrofluoroalkane/beclomethasone dipropionate formulation, has been shown to double lung deposition in adults. The aim of the present study was to assess the total body deposition and distribution oftechnetium-99m-labelled (99mTc) QVARTM in children after inhalation via an AutohalerTM.
Sixteen male asthmatic children (514 yrs) inhaled labelled drug (<4 MBq 99mTc; 100 µg beclomethasone dipropionate) via an Autohaler within 30 min after salbutamol (200 µg) administration. Simultaneous anterior and posterior planar scintigraphic scans(120 s acquisition time) were collected after inhalation of labelled drug.
Mean±sd lung deposition of labelled drug (attenuation-corrected; percentage of ex-actuator dose) was 36.9±9.2, 46.5±11.6 and 54.1±10.7% in children aged 57, 810 and 1114 yrs, respectively. Combined oropharyngeal and gastrointestinal deposition was 59.7±8.2, 48.9±12.3 and 40.3±11.8%. Lung deposition positively correlated with the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Gastrointestinal dose negatively correlated with the FEV1, FVC, height and age.
In older children (1114 yrs), lung deposition was almost identical to that reported inadults using QVARTM. In children aged 510 yrs, lung deposition using QVARTM was greater than the levels measured using other commercial aerosol delivery systems. Oropharygeal and gastrointestinal deposition was inversely related toage.
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