Flashcards in Benzodiazepine Class (Dr. E's lecture) Deck (22)
What are the 5 pharmacological effects of Benzos?
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.
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?
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?
Which subunits does GABA bind to on the GABAa receptor
What subunits do the Benzos bind to on the GABAa receptor?
What is the principal inhibitory neurotransmitter in the CNS?
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
-Most Abundant (60% in the CNS are this type)
-Cortex and Thalamus (they integrate pain and stress)
Alpha 2 subunit
-Hippocampus and Amygdala (memory and emotion/behavior)
What are the main differences between the Benzodiazepine drugs? (hint, there are 3)
1. Potency (receptor binding affinity)
2. Lipid Solubility (ability to cross the BBB, and redistribute to peripheral tissues)
3. Pharmacokinetics (uptake, distribution, metabolism, and elimination)
In general Benzos are highly _______ _______ AND highly ________ to ________ _________
bound to plasma proteins (like albumin)
Which of the Benzos is water soluble in preparation?
Which is the most potent Benzo?
Lorazepam/Ativan: 5 - 10 x potency of Diazepam