Estimation of the dose of fluticasone propionate inhaled by infants after bronchiolitis: Effect on urinary cortisol excretion.
BACKGROUND
Information on the dose of steroid infants inhale from spacer devices and its potential effect on adrenal suppression is limited.


OBJECTIVE
We sought to determine the total dose of fluticasone propionate (FP) inhaled from a spacer device (Babyhaler) with face mask attachment by infants recovering from acute bronchiolitis and the effect of inhaled FP on the infants' overnight urinary cortisol/creatinine ratios (UCCRs).


METHODS
Infants studied were recovering from acute bronchiolitis. In study 1, 22 infants inhaled 150 microg of FP through the Babyhaler. The likely inhaled dose was estimated by trapping it on a filter held within the face mask. In study 2, 40 infants had UCCRs measured before and during 3 months of treatment with either FP (150 microg twice daily, n = 20) or placebo (n = 20).


RESULTS
In study 1 the mean +/- SD dose of captured FP was 12.8 +/- 6.9 microg (ie, 2.1 +/- 1.2 microg/kg). In study 2 the pretreatment UCCR medians (interquartile ranges) were as follows: FP, 22.8 (23.0) nmol/mmol; placebo, 24.0 (28.3) nmol/mmol. Within-group UCCR changes (median and interquartile range DeltaUCCR) were significantly different in the FP group (-8.9 and -20.6 nmol/mmol at 6 weeks and -12.6 and -25.9 nmol/mmol at 12 weeks, respectively; P =.0008) but not in the placebo group ( -5.8 and -10.7 nmol/mmol at 6 weeks and +0.3 and -17.9 nmol/mmol at 12 weeks, respectively; P =.45). Intergroup changes were insignificant in the follow-up period (6 weeks, P =.52; 12 weeks, P =.19).


CONCLUSIONS
After bronchiolitis, infants are likely to inhale approximately 8 % of the nominal steroid dose from the Babyhaler. UCCRs can be used to monitor the bioavailability of inhaled steroids in young infants.
Wong
Jackson
J
Department of Child Health and Institute of Lung Health, University of Leicester, Clinical Sciences Building, Leicester Royal Infirmary, United Kingdom.
Davies
Tim
T
O'Callaghan
Christopher
C
D000208:Acute Disease; D000280:Administration, Inhalation; D000730:Androstadienes / Q000008:administration & dosage* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001988:Bronchiolitis / Q000188:drug therapy* / Q000652:urine; D003404:Creatinine / Q000652:urine; D004311:Double-Blind Method; D000068298:Fluticasone; D006801:Humans; D006854:Hydrocortisone / Q000652:urine*; D007223:Infant; D007231:Infant, Newborn; D036501:Metered Dose Inhalers; D013997:Time Factors
D000730:Androstadienes; D000893:Anti-Inflammatory Agents; D003404:Creatinine; D000068298:Fluticasone; D006854:Hydrocortisone