Theophylline toxicity after the use of aminophylline in the treatment of cerebral vasospasm.

We are reporting a case of theophylline toxicity after the initiation of i.v. aminophylline and isoproterenol in the treatment of cerebral vasospasm. The dose of aminophylline (125 mg/hour) previously recommended results in a toxic serum theophylline concentration in a majority of patients if the infusion is continued for more than 24 to 48 hours. The rapid achievement of an optimal serum level is obtained with a standard loading dose of 8.0 mg/kg. The initial infusion rate should be based on calculated pharmacokinetic data. Maintenance dosing adjustments are then based on serum determinations and the presence of toxic effects.