SELECTED ARTICLES FROM THE RECENT LITERATURE 2005
12/21/05
Ciclesonide-pharmacokinetics and deposition
Summary
Background - Ciclesonide (Cic) is an inhaled corticosteroid (ICS) with unique properties. Some ICS propelled by hydrofluoroalkane (HFA) in MDI devices have different patterns of deposition in the lower airways than seen with the same ICS propelled by the previously used CFC.
Findings - Newman et al of Pharmaceutical Profiles in Nottingham, UK examined the pulmonary deposition and pharmacokinetics (P-K ) of HFA- propelled Cic labeled with technicium 99 in 12 patients with mild asthma. Using 2- dimensional gamma scintigraphy they found that Cic deposition was greater in lung (52%) than in the oropharynx (20%). Furthermore, 3-dimensional SPECT studies showed that Cic deposition in the lungs was highest in the periphery, containing the smaller airways. P-K studies shoed low deposition of the Cic and its active metabolite desiso butyryl-Cic (des-Cic) in the oropharynx, consistent with previous reports of a low incidence of oropharynx side effects in patients using Cic therapy.
Reference
Respir Med 2005;Nov. 3 E pub
Editor's Comments
I have been very impressed with earlier studies of Cic showing that a very low percentage of inhaled Cic is converted into its active metabolite des Cic with an attendant low incidence of adverse side effects in the oropharynx/larynx. The use of the HFA propellant with Cic appears to lead to a "soft" inhaled ICS with low deposition in the pharynx and a greater peripheral deposition in the lower airways.
However, other studies have shown that not all HFA-ICS behave this way with some having a rapid aerosol stream (with more sizable oropharyngeal deposition) similar to that seen in CFC-propelled ICS.
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