Format

Send to

Choose Destination
J Cyst Fibros. 2008 Jan;7(1):79-84. Epub 2007 Jun 27.

Pharmacokinetics and sputum penetration of azithromycin during once weekly dosing in cystic fibrosis patients.

Author information

1
Central Hospital Pharmacy, Escamplaan 900, 2547EX The Hague, The Netherlands. e.wilms@ahz.nl

Abstract

In this study we examined pharmacokinetics, systemic exposure and sputum penetration of azithromycin (AZM) in CF patients on chronic daily AZM therapy after changing to a once weekly dosing scheme. Eight adult CF patients using AZM 500 mg/day were changed to a once weekly dose of 1000 mg during 3 months. Once per month sputum and blood samples were collected. AZM was quantified in blood plasma and polymorphonuclear neutrophils. The cumulative weekly dose was reduced with a factor of 3.5 (7x500 mg vs. 1x1000 mg weekly). This led to a reduction in area under the curve (AUC+/-S.D.) with a factor of 2.5+/-0.8 in plasma, 2.8+/-0.9 in blood, 2.2+/-1.1 in PMNNs and to a reduction in average sputum concentration with a factor of 3.0 (+/-1.5). At 1000 mg once weekly reduced but still substantial concentrations were achieved in PMNNs and in sputum. Although not significant, a tendency towards less than linear reduction was found. In order to calculate and propose an optimal dosing scheme we need to establish a relation between exposure levels and clinical efficacy.

PMID:
17599845
DOI:
10.1016/j.jcf.2007.05.005
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center