[Comparative effects of bamifylline and theophylline on allergenic bronchospasm induced by the provocative inhalation test : double-blind cross-over study].

Protective and curative effects of parenterally administered bamifylline and theophylline on bronchospasm induced by standardized house dust inhalation were studied in two series of eight patients with allergic asthma to house dust. Preventive effects were assessed by variations in liminal allergen dose (LAD) required to double resistance of the air passages (Rap), measured by barometric body plethysmography after determining basal LAD levels. Thirty minutes afer a slow i.v. injection of bamifylline, and LAD mean value reached 920 +/- 950 % of control value, and was still at 830 +/- 1 000 % after 60 minutes. After theophylline, mean LAD values were 750 +/- 980 % at 30 minutes and 700 +/- 970 % at 60 minutes, a non-significant difference. Curative activity was evaluated by studying changes in Rap after the provocative inhalation test with house dust, the test being immediately followed by the administration of either bamifylline or theophylline. Similar results were also obtained employing this test : reduction in Rap of 35 +/- 17 % for bamifylline and 48 +/- 13 % for theophylline (non-significant difference) after 30 minutes, and of 38 +/- 25 % for bamifylline and 48 +/- 14 % for theophylline (non-significant difference) after 60 minutes. These findings suggest that these two xanthine derivatives possess comparable protective and curative effects against bronchospasm induced by allergen inhalation.