Benzodiazepines: Mechanism of action
Sedative-hypnotic, anxiolytic & anti-convulsive agents composed of a fused benzene and diazepine ring that is administered orally or intravenously to produce desired effect (ie., lorazepam, midazolam, diazepam)
Authors: Tracey Rice Usama Malik Amy Fowler Victoria Silva Reviewers: Sara Cho Keira Britto Luiza Radu Brienne McLane* Aaron Mackie* * MD at time of publication
Benzodiazepine binds to gamma-aminobutyric acid (GABAA) receptors in vascular smooth muscle & the central nervous system (CNS)
↑ Opening of chloride channels
Influx of chloride ions into the neuron Hyperpolarization of nerve membrane causing it to be more negative The cell membrane falls below the normal resting potential
Medulla oblongata inhibition
↓ Respiratory drive; ↓ depth & rate of respirations
Temporary cessation of breathing leads to reduced oxygen supply to the brain
↓ Level of consciousness
Pharyngeal muscle relaxation leading to obstruction
Hypoventilation and/or apnea
General CNS inhibition
↓ Neuronal activity
↓ Electrical brain activity
↓ Seizure activity & hypnotic effect
Thalamic & hypothalamic inhibition
Disruption of short & long- term memory consolidation
Limbic system inhibition
↓ Fear emotions (panic & phobia)
Anxiolytic effect (↓ Anxiety)
Smooth muscle inhibition
Smooth muscles become relaxed &/or less spastic
Vasodilation
↓ Preload Hypotension
↓ Cerebral blood flow
Pre-syncope or syncope
Anterograde amnesia
↓ Visuospatial ability, speed of processing & verbal learning
Confusion
↓ Deep stage of non-REM sleep & delayed REM sleep
Rapid sleep
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published July 21, 2024 on www.thecalgaryguide.com