Levodopa

Question 1

Levodopa

Answer 1

Amino acid precursor of dopamine.
Can cross the blood brain barrier.
Once it enters the brain it is converted into dopamine.
Replenishes dopamine levels in the brain.

Question 2

When is it used?

Answer 2

1st line treatment in PD
Improvement in motor performance more noticeable than with dopamine-receptor agonists
Taken at specific times of the day to avoid “OFF” periods (periods where symptoms are worse)

Question 3

Co-careldopa

Answer 3

Levodopa + Carbidopa
Associated with more motor complications

Question 4

Co-beneldopa

Answer 4

Levodopa + Benserazide
Associated with more motor complications

Question 5

Co-careldopa/Co-beneldopa

Answer 5

Peripheral dopa-decarboxylase inhibitors
- Prevent levodopa being converted to dopamine in the blood.
- Levodopa enters the brain and is then converted to dopamine

Less SE (e.g. N + V, CV effects)
Lower dose required for therapeutic effect

Question 6

Side effects

Answer 6

1. Impulse control disorders
2. Excessive sleepiness/sudden onset of sleep
3. Motor complications
4. End of dose deterioration with sorter length of benefit

Question 7

Impulse control disorders

Answer 7

Gambling
Hypersexuality
Binge eating
Excessive shopping

Question 8

Excessive sleepiness/sudden onset of sleep

Answer 8

Warning: driving/operating heavy machinery

Question 9

Motor complications

Answer 9

Dyskinesia = involuntary muscle movement.
Response fluctuations = variations in motor performances

“ON” period = normal function
“OFF” period = weakness + restricted mobility

Question 10

End of dose deterioration with sorter length of benefit

Answer 10

MR preparations may help