Parkinson's disease drugs

Question 1

What goes wrong in parkinson’s disease?

Answer 1

The dopaminergic neurons projecting from the substantial nigra to the striatum are degenerating

Question 2

What happens in a normal person when dopamine receptors in the striatum are bound with dopamine?

Answer 2

Ach and GABA are released. GABA is inhibitory, so it stops unwanted muscle movement

Question 3

Does regular dopamine cross the blood brain barrier? What do you do?

Answer 3

Nope

Give them L-DOPA- it does cross the BBB and is turned into dopamine in the brain

Question 4

T/F, generally L-DOPA treatment is only good for 3-4 years? Why or why not?

Answer 4

True
Patients become less responsive to it- can be due to more degeneration
There can be adverse side effect as well

Question 5

L-DOPA is generally given with carbidopa. Why?

Answer 5

It helps you get more of the drug into the CNS. Dopamine doesn’t get through BBB. L-DOPA with carbidopa keeps the L-DOPA from getting turned into regular DOPA too early. If you don’t take carbidopa with L-DOPA then the L-DOPA will get turned into regular DOPA in the gut and will make you vomit and have nausea

Question 6

L-DOPA requires what for delivery to the striatum?

Answer 6

a neuron from the substantial nigra

Question 7

What is epilepsy?

Answer 7

It is an electrical disturbance in the brain caused by an inherited biochemical defect.

Question 8

Some anti-seizure drugs block high frequency firing of action potentials.

Answer 8

Truth

Question 9

Some anti-convulsants potentiate the effects of GABA to dampen the synaptic nerve impulses. Why?

Answer 9

Increasing GABA is good because GABA release (via Cl- influx) hyper polarizes membranes so it’s more difficult to depolarize them. This can stop unwanted movement.

Question 10

There are a couple of way increase the action of GABA. Give me a few:

Answer 10

Inhibition of GABA transaminase. GABA transaminase is involved in the metabolism of GABA. So this will potentiate the effects of GABA.
Inhibition of GABA uptake- this will increase its effects by allowing it to stay there for longer
GABA works because it opens up the Cl- channel, thereby hyper polarizing the membrane. If you can facilitate the opening of the Cl- channel, you will make the GABA system work better.

Question 11

What are two ways to facilitate the Cl- channel opening?

Answer 11

Benzodiazepines and barbituates

Question 12

What does blocking the T-type calcium channels do? What could it be used to treat?

Answer 12

It decreases the calcium in the cell and doesn’t allow for the calcium mediated calcium release. This doesn’t allow muscles to contract, so this could be used to treat convulsions.

Question 13

What drug is favored by dentists in emergency treatment of seizures?

Answer 13

Benzodiazepines

Question 14

What do benzodiazepines do?

Answer 14

It facilities the opening of Cl- channels. This hyper polarizes the membrane, thereby acting in an inhibitory capacity

Question 15

What do barbiturates do?

Answer 15

It facilities the opening of Cl- channels. This hyper polarizes the membrane, thereby acting in an inhibitory capacity

Question 16

T/F benzodiazepines and barbiturates require GABA to function?

Answer 16

True

Question 17

Blockage of voltage-gated calcium channels would be good for anticonvulsants. How come?

Answer 17

In order for neurotransmitter release, Ca++ must be present. So if you block those calcium channels, then you won’t have any neurotransmitter release.

Question 18

Another thing you can do is block the NMDA receptors. Glutamate binding to the NMDA receptor dislodges the Mg++ block so that calcium can come in. So if you block the NMDA receptors then you can block the influx of calcium, thereby stopping the release of neurotransmitter.

Answer 18

Truth