A Drug’s Mechanism of Action

Image credit: Chad Hagen

What it is. The term “mechanism of action,” or MOA, refers to the biochemical process through which a drug produces its effect. The brain is like an incredibly complex computer, with billions of neurons organized in electrical circuits and networks. These neurons send signals back and forth to each other and control the flow of information through the brain. Drugs affect the way neurons send, receive, and process these signals. 

Why it matters. Seizures occur when the circuits in the brain become imbalanced—the neurons fire off signals in an abnormal fashion, causing a burst of electrical activity. This so-called “electrical storm” can produce a variety of symptoms, including physical convulsions, unusual behavior, and loss of consciousness. Antiepileptic drugs (AEDs) are designed to restore balance in the brain by keeping neurons under control. 

How it works. AEDs have a variety of MOAs that work on certain “targets” in the brain to prevent seizures. But not all AEDs are the same; some make neurons send signals and some stop neurons from sending signals. This, again, is to achieve balance and to make sure that the neurons are working properly—without any rebels firing or misfiring when they shouldn’t be.

Although research has been done to determine how an AED may work in the brain, it is still difficult to know the exact MOA for an AED and how it impacts seizure control. To learn more, talk to your doctor 
or epileptologist.

Originally printed in EpilepsyAdvocate, Spring 2019