The findings of the study, “Potassium Bromide in the Treatment of Pediatric Refractory Epilepsy,” were published in the Journal of Child Neurology.
KBr is the oldest type of anticonvulsant, and has been used to control seizures since the 19th century. It works by activating the gamma-aminobutyric acid (GABAA) receptors, which are channels sitting on the surface of neurons that allow the passage of GABA, a neural signal that inhibits nerve cell activity.
“However, adverse effects on the central nervous system and skin were recognized, and KBr’s use drastically decreased after the introduction of phenobarbital in the 1910s, phenytoin in the 1930s, and carbamazepine and valproate in the 1960s and 1970s,” the investigators said.
“Following reports of efficacy for refractory epilepsy in the 1980s and 1990s, [including for the treatment of severe myoclonic epilepsy in infancy (i.e., Dravet syndrome), acute encephalitis with refractory, repetitive partial seizures, and malignant migrating partial seizures in infants], it has been regaining attention,” they said.
In this study, a group of researchers from the Chiba Children’s Hospital in Japan set out to examine the efficacy and tolerability of KBr for the treatment of children with refractory epilepsy.
The study enrolled 42 children (mean age 6.2 years) with refractory epilepsy — a form of epilepsy that requires more than two medicines to be controlled and has not been successfully suppressed for more than a year — who were treated with KBr (mean treatment duration 15 months) at the hospital between 2008 and 2016.
From the children enrolled in the study (22 with generalized epilepsy, 18 with focal epilepsy and two with Dravet syndrome), 24 experienced a significant improvement in the control of seizures after receiving KBr. These included 21 who experienced a more than 50% reduction in seizure frequency from baseline (moderate effect) and three who became seizure-free (excellent effect).
Treatment was found to be effective in more than half of the children diagnosed with generalized epilepsy (59.1%) and focal epilepsy (55.6%). In addition, KBr also led to significant improvements in seizure control among the two children who had been diagnosed with Dravet syndrome.
The treatment was more effective in children who had tonic seizures (72.2%), generalized tonic-clonic seizures (66.6%), or secondary generalized seizures (75.0%). KBr therapy was less effective among children who had focal seizures (46.2%), infantile spasms (20.0%), or myoclonic seizures (0%).
“KBr is particularly effective for tonic, generalized tonic-clonic, and secondary generalized seizures. However, it is much less effective for myoclonic seizures or infantile spasms. Although its associated adverse effects require further attention, KBr should be considered as a promising and relatively inexpensive anti-epileptic drug for pediatric refractory epilepsy,” the scientists concluded.