W20-L5: Transmitters and Receptors Flashcards Preview

Matt's Block 06 - Neuro block > W20-L5: Transmitters and Receptors > Flashcards

Flashcards in W20-L5: Transmitters and Receptors Deck (14):

Where can drugs effect the CNS?

They can effect action potentials, synthesis of NT, release of NT, re-uptake, breakdown and actions at receptor


Difference between cocaine and amphetamine

Cocaine blocks re-uptake

Amphetamine causes non-exocytotic release


What are two treatment options for epilepsy?

A. Reduce excitatory input (Phenytoin)
B. Enhance inhibitory input (Benzodiazepines)


What are benzodiazepines used in?

– Epilepsy
– Anxiety
– Sleep disorders
– Premedication
• Sedation for medical
– Acute alcohol withdrawal


What is the problem with barbiturates?

They have a low therapeutic index and are highly addictive


How do benzodiazepines work?

Interact with GABA A receptors only, increases the frequency of Cl- channel opening


What type of modulation do benzodiazepines work by?

Allosteric modulation


Why can you not die from an overdose of a single benzodiazepines?

There is a ceiling in the amount of activation a receptor channel can open which is below death


What are some advantages of allosteric modulators?

• Ceiling of effect of inhibitors – increased therapeutic window
• Positive modulation of endogenous agonist effect rather than continuous effect of exogenous agonist
– physiological regulation continues
• Great receptor subtype selectivity possible


What are some problems with benzodiazepines?

• Tolerance
– Gradual escalation of dose needed
• Dependence
– Signs of physical & psychological withdrawal
• Nausea, tremor, also anxiety, depression, insomnia – Gradual dose reduction


What is potency?

Relative position of the dose-effect curve along the dose axis


When is the only case in which low potency is a disadvantage?

if the dose is so large that it is awkward to administer


What is efficacy?

The ability of a drug to do the right thing


Barbiturates V Benzodiazpines

Both potentiate the effect of GABA
• Benzodiazepines increase the frequency of the chloride ion channel opening at the GABAA receptor (increases GABA potency)
• Barbiturates produce their pharmacological effects by increasing the duration of chloride ion channel opening at the GABAA receptor (increase GABA efficacy)

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