Aminophylline toxicity--how many hospital asthma deaths does it cause?

Aminophylline administration was compared in 43 patients who died from asthma and 43 matched controls who were admitted, suffering from acute asthma, to hospitals in the North East Thames Region. A computer program, which used information about individual characteristics, medical history and drug intake, was employed to calculate the serum theophylline levels which were likely to have resulted from the hospital treatment each patient received. Toxic theophylline levels were estimated to have occurred in 21% (9/43) of fatal cases and 7% (3/43) controls. Details of four patients who died when their serum theophylline levels were likely to have been very high are presented. Six fatal cases suffered gastro-intestinal bleeds during their final illness: four of these had theophylline levels which were calculated to have been toxic at the time of bleeding.