BENZODIAZEPINES' MECHANISM OF ACTION, CLINICAL USES AND CLASSIFICATION

Introduction

Benzodiazepines are a class of drugs that have the pharmacologicall actions of anxiolitics, sedatives, hipnotics, muscle relaxants and anticonvulsivants. Their clinical indication cannot be generalized but specified by each agent.

Some of the most prescribed benzodiazepines are:

Alprazolam Anxiety
Diazepam Anxiety,muscle relaxation,status epilepticus
Flurazepam Insomnia
Lorazepam Anxiety
Midazolam Anesthesia
Oxazepam Anxiety
Prazepam Anxiety
Temazepam Insomnia
Triazolam Insomnia


Mechanism of Action

Gamma amino butyric acid (GABA) is an inhibiting neurotransmitter that is present on human brains. As shown in the animation, gamma amino butyric acid promotes opening of a postsynaptic receptor, the GABA-A receptor.

This opening leads to a increased conductance to cloride ions, which produces membrane hiperpolarization, this induces a neuronal inhibition.

The binding of benzodiazepines to the GABA-A receptor increases the affinity of gamma amino butyric acid (GABA) and its receptor, thereby increasing the opening frecuency of GABA-A receptor.As a consequence of this, benzodiazepines potentiate GABAergic neurotransmission.

 

References:

  • Modern Pharmacology with Clinical Applications, Sixth Edition by Charles Craig
  • Principles of Pharmacology: The Pathophysiologic Basis of Drug Therapy, Second Edition by David E Golan