Comparison of potency of inhaled beclomethasone and budesonide in New Zealand: retrospective study of computerised general practice records.
OBJECTIVE
To determine whether inhaled budesonide and beclomethasone are equipotent in the treatment of asthma in primary care.


METHODS
Retrospective study of computerised clinical records from 28 general practices in New Zealand.


METHODS
5930 patients who received 16 725 prescriptions for inhaled budesonide or beclomethasone from 1 July 1994 to 30 June 1995.


METHODS
General practices on the database of the Royal New Zealand College of General Practitioners Research Unit. Linked information from secondary care was available for a subset of the practices.


METHODS
Mean prescribed daily inhaled corticosteroid dose.


RESULTS
The daily prescribed dose was higher for patients receiving inhaled budesonide (mean 979 microg) than beclomethasone (mean 635 microg), a difference of 344 microg (95% confidence interval 313 to 376 microg). This difference was consistent in all age bands and with different types of inhalation device. Evidence of systematic prescribing of higher doses of budesonide to patients with more severe asthma was not found.


CONCLUSIONS
In primary care in New Zealand evidence suggests that budesonide is less potent than beclomethasone. Consideration of validated, established, and other possible markers of asthma severity did not support confounding by severity as a reason for the higher prescribed doses of budesonide. Pending further epidemiological evaluation, international asthma guidelines may need to be modified on the equivalence of inhaled corticosteroid doses. Furthermore, the comparative potency of newly developed inhaled steroids in clinical trials will need to be confirmed in appropriately designed epidemiological studies based in general practice.
Pethica
B D
BD
Wellington Asthma Research Group, Wellington School of Medicine, University of Otago, Wellington, PO Box 7343, Wellington South, New Zealand. WARG.Sec@wnmeds.ac.nz
Penrose
A
A
MacKenzie
D
D
Hall
J
J
Beasley
R
R
Tilyard
M
M
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy*; D001507:Beclomethasone / Q000008:administration & dosage*; D019819:Budesonide / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D009520:New Zealand; D012189:Retrospective Studies
D018927:Anti-Asthmatic Agents; D019819:Budesonide; D001507:Beclomethasone