over a two-and-a-half-year period , 22 patients ( group 1 ) had plasma theophylline concentrations of 37 +/- 1 micrograms/ml ( mean +/- se ) and experienced no severe toxicity ( i.e. , ventricular extrasystoles or tachycardia , seizures , cardiovascular collapse , or death ) .
C0039771
theophylline
C0036572
seizures