Theophylline mitigates the bronchoconstrictor effects of sulfur dioxide in subjects with asthma

J Allergy Clin Immunol. 1992 Apr;89(4):789-94. doi: 10.1016/0091-6749(92)90432-2.


The objective of the study was to investigate the ability of a sustained-release (SR) theophylline tablet (Uniphyl; Purdue Frederick Co., Norwalk, Conn.) to block or mitigate sulfur dioxide (SO2)-induced bronchoconstriction in adult subjects with asthma. Eight subjects participated in a double-blind, crossover study with a 400 mg theophylline tablet or placebo once a day for a week before a 10-minute SO2 challenge. FEV1 and total respiratory resistance (RT) were measured before and after the SO2 challenge and on a different day before and after an air exposure. After exposure to SO2, average values of FEV1 dropped 16% after placebo treatment and 7% after theophylline treatment. The corresponding percentages for RT were a 37% increase after placebo and a 7% increase after theophylline treatment. Analysis of variance demonstrated a significant difference between the SO2-induced decrease in FEV1 and increase in RT after SR theophylline treatment compared with that of placebo treatment. Thus, we conclude that SR theophylline tablets, taken at this concentration for 1 week, mitigate SO2-induced bronchoconstriction.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Asthma / drug therapy*
  • Bronchoconstrictor Agents / pharmacology*
  • Delayed-Action Preparations
  • Double-Blind Method
  • Female
  • Forced Expiratory Volume
  • Humans
  • Male
  • Middle Aged
  • Sulfur Dioxide / pharmacology*
  • Theophylline / administration & dosage*
  • Theophylline / therapeutic use


  • Bronchoconstrictor Agents
  • Delayed-Action Preparations
  • Sulfur Dioxide
  • Theophylline