Use of hydrofluoroalkane propellant delivery system for inhaled albuterol in patients receiving asthma medications.
OBJECTIVE
This study was undertaken to assess drug-use patterns associated with albuterol delivery via a new propellant device compared with conventional chlorofluorocarbon (CFC) metered-dose inhalers (MDIs) in patients taking asthma medications in a population with pharmacy benefits.


BACKGROUND
In addition to their ozone-depleting properties, conventional CFC inhalers often deliver inconsistent doses because of loss of prime and temperature instability. A new propellant, hydrofluoroalkane (HFA), incorporates a re-engineered delivery system associated with dosing reproducibility throughout the life of the canister.


METHODS
Drug markers associated with management of asthma were used to identify a study cohort of new users of inhaled albuterol from a geographically diverse pharmacyclaims database from July 1, 1997, through December 31, 1997. A population of 282,879 members was identified over the 20-month follow-up period. In addition, a subset of chronic albuterol inhaler users (> or = 12 months; n = 96,879) was also identified to support a longitudinal analysis. Disease severity was controlled for by use of inhaled corticosteroids (ICS). To control for canisters received via physician office samples, HFA patient use was corrected by a physician-based canister adjustment based on HFA sample data.


RESULTS
A total of 53.1% of participants were women and 46.1% were men; most of the population (72.5%) was <65 years of age. Canister use for HFA patients was consistently lower (2.7+/-3.2 vs 5.4+/-6.7) than for CFC MDIs for the entire cohort over the 20-month assessment period. This difference was consistently observed for albuterol canister use in patients with and without concomitant ICS use (3.3+/-3.8 HFA vs 7.2+/-7.5 CFC for ICS users and 2.1+/-2.1 HFA vs 4.1+/-5.7 CFC for non-ICS users). Time to next prescription also was longer for HFA patients than for CFC patients (61.6+/-50.9 days HFA vs 47.3+/-40.8 days CFC). When duration of therapy and physician samples associated with product launch were controlled for, similar differences were consistently observed. CFC patients used, on average, 1.3 more canisters per year than did HFA patients (P < 0.001), averaging 10.7 canisters (95% CI, 10.6 to 10.7), compared with 9.4 canisters used by HFA patients (95% CI, 8.9 to 9.9). Further analyses indicated that this finding was consistent when ICS use was controlled for (CFC plus ICS mean, 11.9 canisters vs HFA plus ICS mean, 10.4 canisters; P < 0.001).


CONCLUSIONS
This study provides useful information about the effect of use of a new albuterol delivery system on asthma inhaler management. These data suggest that CFC patients use an average of 1.3 more canisters per year compared with HFA patients independent of asthma severity as measured by ICS use. This improvement in dosing characteristics has the potential to translate into enhanced economic outcomes.
Boccuzzi
S J
SJ
The Institute for Effectiveness Research, LLC, Bridgewater, New Jersey 08807, USA.
Wogen
J
J
Roehm
J B
JB
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000335:Aerosol Propellants; D000368:Aged; D000420:Albuterol / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D017402:Chlorofluorocarbons; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006845:Hydrocarbons, Fluorinated; D007223:Infant; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D005466:Fluorocarbons
D000335:Aerosol Propellants; D000420:Albuterol; D001993:Bronchodilator Agents; D017402:Chlorofluorocarbons; D006845:Hydrocarbons, Fluorinated; C094049:apaflurane; D005466:Fluorocarbons