A medicine called tranexamic acid can block certain brain and spinal cord signals by attaching to specific receptors, and it works much better on some types of signals than others — like a key that fits one lock better than another.

A medicine called tranexamic acid, at levels found in the spinal fluid after heart surgery, might interfere with a natural calming system in the spinal cord and brain, which could make seizures more likely.

A common anesthesia gas called isoflurane can undo the blocking effect that a blood-clotting drug (tranexamic acid) has on certain brain signals in the spine, bringing those signals back to normal — but another anesthesia drug, propofol, needs to be given in much higher doses to do the same thing.

After heart surgery, a drug called tranexamic acid can build up in the fluid around the brain and spinal cord, and this buildup might interfere with brain signals in a way that increases the chance of seizures after surgery.