Breast Cancer Drugs Could Potentially Stop Seizures

Blocking estrogen production by using an aromatase inhibitor stopped seizures in animal models.

In a recent study, researchers found that a drug class for treating breast cancer, aromatase inhibitors, effectively reduces seizures in animal models. Investigators also learned that seizures stimulate estrogen production in both male and female brains, which makes the seizure more severe.

Current seizure medications are typically not targeted and can cause drowsiness, dizziness, or difficulty concentrating. Stopping estrogen production at the beginning of the seizure could be a new treatment approach, according to the study.

"Status epilepticus is a neurological emergency. This occurs when large groups of connected neurons fire excessively and in synchrony for a prolonged time,” said senior study author Catherine S. Woolley, PhD. “Recognizing that estrogen synthesis during seizures fuels seizure activity gives researchers a specific target for therapeutically breaking the dangerous escalation cycle."

According to the study, published in eLife, researchers were able to stop estrogen synthesis just after seizure onset and found that seizures were suppressed in both animals and in hippocampal electroencephalogram (EEG) recordings.

The researchers injected animals with either an inert substance or an aromatase inhibitor (either letrozole or fadrozole) after the onset of a chemically-induced seizure and monitored the animals for up to 6 hours.

Researchers found that the aromatase inhibitors suppressed seizures in both sexes. In another part of the study, researchers found that there was a 2- to 3-fold increase in estrogen production in the hippocampus of both sexes.

Researchers said that new approaches to control acute seizures are needed and are hopeful their findings can contribute to filling this unmet need.

"Hopefully, this new study will trigger clinical trials to determine the efficacy and safety of currently available aromatase inhibitors in patients with status epilepticus," said Stephen M. Smith, MB, BS, PhD, director of medical critical care at the VA Portland Health Care System.