Pediatric Seizures: IV or IM Benzodiazepines?

Abstract & Commentary

Source: Chamberlain JM, et al. A prospective, randomized study comparing intramuscular midazolam with intravenous diazepam for the treatment of seizures in children. Pediatr Emerg Care 1997;13:92-94.

Investigators from an urban pediatric ed and a suburban community ED compared IM midazolam and IV diazepam in the treatment of pediatric motor seizures. Eligible patients were younger than 18 years, and these patients presented to either ED with motor seizures lasting at least 10 min. Patients were excluded if an IV was already in place on arrival or an anticonvulsant had been administered for the current seizure episode. In a non-blinded fashion, patients were randomized to receive either 0.2 mg/kg IM midazolam or 0.3 mg/kg IV diazepam.

Twenty-four children were enrolled and completed the study protocol; 11 received diazepam, and 13 received midazolam. The two groups were similar in age, gender, and prior seizure history. Both medications were effective at stopping the seizures; there was one treatment failure in each group. Children in the IM midazolam group received their medication sooner (3.3 ± 2.0 min vs 7.8 ± 3.2 min), and this group had more rapid cessation of seizures after arrival to the ED (7.8 ± 4.1 min vs 11.2 ± 3.6 min). Time-to-cessation of seizures after medication administration was 4.5 ± 3.0 min for IM midazolam and 3.4 ± 2.0 min for IV diazepam (P = 0.32).


Both in the ED and prehospital setting, IV access in children can be difficult, particularly in a child having a seizure. Two recent surveys revealed that only 55-66% of pediatric offices stock supplies to start an IV line. Despite the small sample size and the possibility that some of the patients’ seizures might have stopped spontaneously rather than from the medication, this study demonstrates that IM midazolam is an effective anticonvulsant for children. Midazolam is dependably absorbed when given IM, and subsequent distribution to the brain is rapid. The availability of an effective, reliable, and rapidly-absorbed IM anticonvulsant is welcome for children when IV access is not possible or difficult to obtain.


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