Aminophylline and isoproterenol in the treatment of cerebral vasopasm

Eighteen patients with cerebral vasospasm following subarachnoid hemorrhage were treated with 21 trials of intravenous aminophylline and isoproterenol. After angiographic demonstration of spasm, all patients were started on a continuous intravenous infusion of aminophylline 125 mg/hr and isoproterenol 125 micrograms/hr, preferably for a period of at least five days before the medications were tapered. Of the 21 treatment trials, there were 11 definite beneficial responses and ten failures. This study emphasizes the importance of instituting this therapy as rapidly as possible following the confirmation of symptomatic cerebral vasospasm. In addition, if a response occurs it will be noted within 24 hours of institution of the medications. If no response is noted following this time period, the medications should be discontinued. The major complications of this therapy include hypotension, tachycardia and arrythmias. These complications may necessitate diminishing the dosage of the medications. However, if a response has been obtained, every effort should be made to avoid discontinuing therapy prematurely since cerebral vasospasm may recur. The use of isoproterenol and aminophylline is based on their demonstrated ability to increase cyclic adenosine monophosphate (cyclic AMP) levels in vascular smooth muscle, thus producing relaxation of vasospasm.