Seizure-Inducing Drugs Used for the Critically Ill

Abstract

Critically ill patients are subjected to numerous medication effects during their stay in the intensive care unit (ICU). Some of them have epileptogenic potentials. The most common pathophysiologic mechanism is through blockade of the γ-aminobutyric acid (GABA) receptor, and the most commonly used family of ICU drugs, reducing the seizure threshold, is the antibiotics. The exact role of these medications in inducing a clinical or subclinical seizure, in the context of cerebral injury or other multiorgan failure, is in many cases unclear. Fortunately, the ability to prevent seizures in critically ill patients is within our grasp. However, the intensivist should always seek a medication as the cause of the witnessed seizure and should consider replacing it with another having less epileptogenic potential.

To minimize seizures, the same cautious measures used to minimize or eliminate any unwanted drug side effect should be followed. Always attempt to start and keep the patient on the lowest dose of the medication necessary to exert the desired therapeutic effect. When upward titration in dosage is necessary, increase slowly, keeping a watchful eye on all laboratory and clinical indicators of success or failure. Free levels of antiepileptic or other medications must be considered in the critically ill because of the numerous factors affecting their final action on the target in the central nervous system. A GABAergic receptor agonist antiepileptic drug should be used as first-line antidote in most of the cases.