|P. Chervinsky, MD, New England Research Center, North Dartmouth, Mass, evaluated oral theophylline (Uniphyl Tablets) and albuterol (Proventil Repetabs) in sleep-interrupted asthma patients. Once daily evening controlled-release theophylline compared with twice daily extended-release albuterol showed improved morning pulmonary function beyond the initial l4 days of treatment. Both medications produced similar symptom improvement and side effects.|
Nocturnal asthma patients, reporting night awakenings on >3
days per week, participated in this double-blind, randomized
parallel design study. One group of 54 prequalified to tolerate
oral albuterol twice daily at 4 mg or higher. The remaining 43
patients underwent titration to achieve a morning serum theophylline
level in the 12-18 mcg/ml range.
Each patient continued on the titrated dose of theophylline or albuterol for the 28-day study period. Clinic visits included pretreatment (baseline), Day 14, and Day 28 for symptom assessment and morning pulmonary function tests. Twice daily (morning and evening) peak expiratory flow rates (PEFRs), taken at home, provided additional efficacy data.
|Results of treatment||
Once daily theophylline compared with twice daily albuterol led
to higher improvements in pulmonary function. The observations
included forced vital capacity (FVC), expiratory volume (FEV),
expiratory flow over 25% to 75% of FVC (FEF 25-75), and PEFR
measured on Day 14. The improvements, on average, increased
further on Day 28, but only in the theophylline group.
Albuterol patients averaged a slight decrease or no change in
pulmonary function between Day 14 and Day 28; however, pulmonary
function values were significantly higher than at prestudy.
Daily at home PEFR results support the laboratory spirometric
Overall, mean symptom scores improved similarly in both treatment groups, according to physician assessment on Day 14 and Day 28. The symptom battery included cough, wheeze, dyspnea, chest tightness, and night awakening.
The incidence of reported side effects was 40.9 percent with once daily theophylline and 37.3 percent with twice daily albuterol. Headache occurred more often with theophylline treatment and nervousness with albuterol. In the investigator's opinion about one half of the reported side effects are not related to the assigned study drugs.
|Investigator's interpretation of results||Chervinsky found that once daily theophylline led to improvement in pulmonary function beyond the first two weeks of treatment. Is this difference "due to theophylline's nonbronchodilator effects" as proposed by the presenter? Perhaps, a follow-up study controlling for dosing schedule would help clarify the observed Day 28 difference in pulmonary function.|
For professional correspondence, please contact Dr. Chervinsky at: firstname.lastname@example.org
Presented at the Annual Meeting of the American College
of Allergy, Asthma and Immunology on 9-10 November 1996
CONRAD NOTES, © January 1997 All Rights Reserved
Eugene A. Conrad, PhD, MPH / ISSN 1078 / posted 8-Feb-1997