Benzodiazepines: Mechanism of Action and Side Effects
BZDs are sedative-hypnotic agents. Examples: Lorazepam, Diazepam, Clonazepam, Alprazolam.
Pharmacokinetics Absorbed by GI tact and metabolized by liver
Pharmacodynamics 1 BZD bind to site on GABA-A receptor
Dose adjustment if liver disease or older age
Interaction with inhibitors of CYP 3A4
Authors: Usama Malik Amy Fowler Reviewers: Aaron Mackie* * MD at time of publication
Accumulation of metabolites vir 4, LOC
Note: • GABA is the principal inhibitory neurotransmitter in the brain and plays an important regulatory role in reducing the activity of many neurons Amygdala-centered circuit regulates fear while CSTC regulate worry Lorazepam, Oxazepam, and Tamazepam are not metabolized by the liver, and excreted by the kidney.
Muscle relaxant 1 Binding triggers influx of Cl- ions leading to hyperpolarization of membrane • • 4, seizures, hypnotic
spinal activity cord firing of neurons 4, cerebral Abbreviations: • BZD: Benzodiazepines • GABA: Gamma aminobutyric acid • CSTC: Cortico-Striato-Thalamo-Cortical NI, cortex activity • Respiratory amygdala-centered CSTC circuit activity Adverse Effects Depression circuit activity Overdose 4, fear, 4, panic Anxiolytic Anterograde Ataxia, slurred Dependence, Rare unless co-and 4, phobia amnesia, speech, tolerance ingestion with other CNS depressant confusion weakness