Dose-ranging study of the clinical efficacy of twice-daily triamcinolone acetonide inhalation aerosol in moderately severe asthma.
OBJECTIVE
This multicenter, double-blind, placebo-controlled study evaluated the dose response to 6 weeks of triamcinolone acetonide inhalation aerosol (TAA, 100 microg per puff) in patients with moderately severe asthma.


METHODS
A total of 285 patients were randomly assigned to treatment with 1, 2, 4, or 8 puffs TAA (total daily doses of 200, 400, 800, and 1,600 microg, respectively), administered twice daily, or matching placebos. Efficacy was assessed by changes in FEV1, asthma symptom scores, albuterol use, and peak flow rates.


RESULTS
Linear trend analyses showed a dose response for all efficacy variables across the dose range of 200 to 1,600 microg daily. Therapeutic activity was evident at a dose of 200 microg daily for all variables, with significant clinical efficacy (p<0.05) demonstrated for all doses except for reduction in inhaled albuterol use which achieved statistical significance at 400 microg/d. Daily doses of 400 microg and higher showed response plateaus at 3 weeks of treatment that were maintained for the remainder of the trial. The incidence of adverse events was similar in all treatment groups, although more patients treated with TAA reported pharyngitis in a dose-related manner.


CONCLUSIONS
Our findings suggest that most patients with chronic, moderately severe asthma can be treated adequately with doses of TAA between 200 microg (1 puff bid) and 800 microg (4 puffs bid) daily. At this dose range, clinically significant improvements are evident in symptoms, pulmonary function, and rescue medication use.
Welch
M J
MJ
Allergy and Asthma Medical Group and Research Center, San Diego, USA.
Levy
S
S
Smith
J A
JA
Feiss
G
G
Farrar
J R
JR
D000280:Administration, Inhalation; D000293:Adolescent; D000318:Adrenergic beta-Agonists / Q000627:therapeutic use; D000328:Adult; D000336:Aerosols; D000420:Albuterol / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002908:Chronic Disease; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005069:Evaluation Studies as Topic; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D005938:Glucocorticoids / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D015994:Incidence; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D010612:Pharyngitis / Q000139:chemically induced; D010919:Placebos; D013997:Time Factors; D014222:Triamcinolone Acetonide / Q000008:administration & dosage* / Q000009:adverse effects
D000318:Adrenergic beta-Agonists; D000336:Aerosols; D000893:Anti-Inflammatory Agents; D001993:Bronchodilator Agents; D005938:Glucocorticoids; D010919:Placebos; D014222:Triamcinolone Acetonide; D000420:Albuterol