Benzodiazepine Class (Dr. E's lecture) Flashcards
Please note that the drug card information is for Educational Use ONLY, and the source is from Carrie Bowman's glossary of drug cards permitted by use of Georgetown NAP students. No permission is given to use these cards for anything other than as a study resource for our program.
What are the 5 pharmacological effects of Benzos?
Anxiolysis Sedation Anterograde Amnesia Anticonvulsant Actions Muscle Relaxation (Spinal Level)
Do Benzos produce skeletal muscle relaxation? Is this good for surgery?
do NOT produce skeletal muscle relaxation adequate for surgery
Action of Benzos does NOT alter the dose of _________ _________ required.
muscle relaxants
What is the potential for tolerance/abuse in Benzos?
LESS than that for opioids and Barbs b/c there is a ceiling effect
Is there an issue for OD?
Greater margin of safety in OD
What are the effects of Benzos on hepatic enzymes?
DO NOT induce hepatic enzymes
What drugs have Benzos replace? What for? Which benzo is the main one used?
Replaced Barbiturates for premeds and MAC (Sedation) –> MIDAZOLAM
What do the Benzos as a class have that makes them well liked for their sedative qualities?
Have a SPECIFIC Antagonist- Flumazenil
What is the structure of the Benzos?
Benzene Ring
fused with a 7-membered diazepine ring
-opens at physiologic pH and is activated
What is the MOA of the Benzos?
- Facilitate the action of GABA at the GABAa receptor
- DO NOT activate GABAa receptor
- Increase affinity/potency of GABA for GABAa receptor
- FACILITATE, DO NOT activate!
Describe the GABAa receptor. (with affinity of GABA binding to GABAa receptor)
- opening of Cl gated channels
- increases Cl conductance
- hyperpolarization of the POST-synaptic membrane
- increases resistance of post-synaptic membrane to excitation
Do Benzos act pre- or post- synaptically?
POST SYNAPTICALLY
Which subunits does GABA bind to on the GABAa receptor
alpha subunits
What subunits do the Benzos bind to on the GABAa receptor?
gamma
What is the principal inhibitory neurotransmitter in the CNS?
GABA
Mostly, the GABAa receptors are found where? minimal effects where?
postsynaptic membranes in the CNS!- minimal effects OUTSIDE the CNS!!!!
Describe the 2 different Alpha subunits of the GABAa receptor and the effects when a ligand is bound to them.
Alpha 1 subunit
- Sedative effects
- Most Abundant (60% in the CNS are this type)
- Cortex and Thalamus (they integrate pain and stress)
Alpha 2 subunit
- Anxiolytic effects
- Hippocampus and Amygdala (memory and emotion/behavior)
What are the main differences between the Benzodiazepine drugs? (hint, there are 3)
- Potency (receptor binding affinity)
- Lipid Solubility (ability to cross the BBB, and redistribute to peripheral tissues)
- Pharmacokinetics (uptake, distribution, metabolism, and elimination)
In general Benzos are highly _______ _______ AND highly ________ to ________ _________
Lipid soluble
bound to plasma proteins (like albumin)
Which of the Benzos is water soluble in preparation?
Midazolam/ Versed
Which is the most potent Benzo?
Lorazepam/Ativan: 5 - 10 x potency of Diazepam
Which benzo is the most potent amnestic used in anesthetic practice?
Lorazepam/Ativan
