A comparison of intraosseous and intravenous routes of administration for antiseizure agents.

Intravenous (i.v.) access for administration of antiepileptic drugs can be time-consuming and difficult in an infant during a seizure. This study examined the intraosseous (i.o.) route as an alternative means of vascular access for drug administration in an animal-seizure model. Domestic swine (13-20 kg) were anesthetized with ketamine (20 mg/kg i.m.) and alpha-chloralose (80 mg/kg i.v.) and given gallamine (4 mg/kg i.v.) to prevent muscle fasciculations. Tracheosotomies were performed and the animals were ventilated with a Harvard respirator. The left femoral vein was cannulated and pentylenetetrazol (PTZ) (100 mg/kg) was given to elicit epileptogenic activity. Sixty seconds after onset of epileptogenic activity, the animals received saline or diazepam (DZP) (0.1 mg/kg) or propranolol (2.5 mg/kg) i.v. or via the i.o. route (18-gauge spinal needle placed in the right proximal tibia). Both DZP and propranolol were effective in suppressing epileptogenic activity via the i.v. or i.o. routes. Thus, the i.o. route is a rapid and effective alternative route for the administration of antiepileptic drugs when an i.v. route cannot be readily established.