EFFECT OF (DL) 3,7-DIHYDRO-1,8-DIMETHYL-3-(2-METHYLBUTYL)-1H-PURINE-2,6-DIONE ON EXERCISE-INDUCED BRONCHOSPASM

  • 1 January 1981
    • journal article
    • research article
    • Vol. 19  (7) , 297-302
Abstract
The clinical activity of a synthetic theophylline derivative, (dl)3,7-dihydro-1,8-dimethyl-1-3-(2-methyl-butyl)-1H-purine-2,6-dione was studied, both after short-term treatment and in prevention of exercise-induced asthma (EIA). The action of the new compound at 2 dosages was compared with that of anhydrous theophylline at a standard dose of 600 mg/day. The trial included 15 asthmatics, 11 males and 4 females, who showed EIA with reversible bronchospasm (improvement of at least 15% of forced expiratory volume (FEV1) after administration of salbutamol at a dose of 200 .mu.g by a predosed aerosol). Asthma was provoked by free running on a flat surface. The test was considered positive if the FEV1 was reduced by at least 20% from baseline level. Only 11 patients completed the protocol. In 4 cases the treatment had to be withdrawn due to the onset of adverse side effects. After 3 days of treatment, the drug caused a statistically significant improvement of FEV1 in comparison with baseline, but no difference from that caused by theophylline. No significant difference was noted between low and high doses of the tested drug. In 8 of 14 patients theophylline and the investigational drug proved equally effective. Two patients were protected only by theophylline, 1 only by the investigational drug and 3 failed to be protected by either agent. The higher dose of the investigational drug protected against EIA in all the subjects protected by theophylline with 1 exception. Of the 2 doses tested, the lower one has the same therapeutic effect without the most significant side effects.