title: Quantification of Aerosol Hydrofluoroalkane HFA-134a Elimination in the Exhaled Human Breath Following Inhaled Corticosteroids Administration.
abstract: Inhaled corticosteroids (ICS) and β2-agonists are the primary pharmacotherapies of asthma management. However, suboptimal medication compliance is common in asthmatics and is associated with increased morbidity. We hypothesized that exhaled breath measurements of the aerosol used in the inhaled medications might prove useful as surrogate marker for asthma medication compliance. To explore this, 10 healthy controls were recruited and randomly assigned to ICS (Flovent HFA) or short acting bronchodilators (Proventil HFA). Both inhalers contain HFA-134a as aerosol propellant. Exhaled breath sampling and pulmonary function tests were performed prior to the inhaler medication dispersion, immediately after inhalation, then at 2, 4, 6, 8, 24, and 48 hours postadministration. At baseline, mean (SD) levels of HFA-134a in the breath were 252 (156) pptv. Immediately after inhalation, HFA-134a breath levels increased to 300 × 10(6) pptv and were still well above ambient levels 24 hours postadministration. The calculated ratio of forced expiratory volume in 1 second over forced vital capacity did not change over time following inhaler administration. This study demonstrates, for the first time, that breath HFA-134a levels can be used to assess inhaler medication compliance. It may also be used to evaluate how effectively the medicine is delivered.
authors.affiliation: Department of Pediatrics and Pediatrics Exercise Center, University of California, Irvine, Irvine, California, USA.
authors.forename: Hye-Won
authors.initials: HW
authors.lastname: Shin
authors.affiliation: Department of Chemistry, University of California, Irvine, Irvine, California, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Barletta
authors.affiliation: Miller Children's Hospital, Orange, California, USA.
authors.forename: Leila
authors.initials: L
authors.lastname: Yoonessi
authors.affiliation: Department of Chemistry, University of California, Irvine, Irvine, California, USA.
authors.forename: Simone
authors.initials: S
authors.lastname: Meinardi
authors.affiliation: Department of Pediatrics and Pediatrics Exercise Center, University of California, Irvine, Irvine, California, USA.
authors.forename: Szu-Yun
authors.initials: SY
authors.lastname: Leu
authors.affiliation: Department of Pediatrics and Pediatrics Exercise Center, University of California, Irvine, Irvine, California, USA.
authors.forename: Shlomit
authors.initials: S
authors.lastname: Radom-Aizik
authors.affiliation: Miller Children's Hospital, Orange, California, USA.
authors.forename: Inderpal
authors.initials: I
authors.lastname: Randhawa
authors.affiliation: Miller Children's Hospital, Orange, California, USA.
authors.forename: Eliezer
authors.initials: E
authors.lastname: Nussbaum
authors.affiliation: Department of Chemistry, University of California, Irvine, Irvine, California, USA.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Blake
authors.affiliation: Department of Pediatrics and Pediatrics Exercise Center, University of California, Irvine, Irvine, California, USA.
authors.forename: Dan M
authors.initials: DM
authors.lastname: Cooper
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage* / Q000737:chemistry; D000328:Adult; D000335:Aerosol Propellants / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D000336:Aerosols; D000420:Albuterol / Q000008:administration & dosage* / Q000737:chemistry; D001944:Breath Tests; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000737:chemistry; D002140:California; D002626:Chemistry, Pharmaceutical; D016903:Drug Monitoring / Q000379:methods*; D045853:Exhalation; D005260:Female; D000068298:Fluticasone / Q000008:administration & dosage* / Q000737:chemistry; D005541:Forced Expiratory Volume; D064368:Healthy Volunteers; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D008297:Male; D008450:Maximal Midexpiratory Flow Rate; D055118:Medication Adherence; D008875:Middle Aged; D011237:Predictive Value of Tests; D014797:Vital Capacity; D005466:Fluorocarbons
chemical_list: D000305:Adrenal Cortex Hormones; D000335:Aerosol Propellants; D000336:Aerosols; D000420:Albuterol; D001993:Bronchodilator Agents; D000068298:Fluticasone; D006845:Hydrocarbons, Fluorinated; C094049:apaflurane; D005466:Fluorocarbons
keywords: 1,1,1,2-Tetrafluoroethane; Albuterol inhaler; HFA-134a; aerosol; asthma; bronchodilator; compliance; gas chromatography; hydrofluoroalkane; inhaled corticosteroids (ICS); propellant