PD- L-Dopa DI

Question 1

L-dopa is a precursor to what?

Answer 1

DA!

Question 2

PK/PD of L-dopa: transportation

Answer 2

Transported via a large amino acid transporter in the GI tract and BBB

Question 3

PK/PD of L-dopa: metabolism

Answer 3

95% metabolized into DA by LAAD

Question 4

PK/PD of L-dopa: CNS penetration

Answer 4

<1% of the dose reaches the CNS without a decarboxylase inhibitor (CARBIDOPA!)

Question 5

PK/PD of L-dopa: elimination

Answer 5

Renally eliminated

Question 6

CIs of L-dopa:

Answer 6

breastfeeding and closed-angle glaucoma

Question 7

L-dopa ADEs

Answer 7

Dyskinesia, “on-off” phenomena when the effectiveness decreases over time, psychiatric disturbances, vivid dreams, GI effects, orthostatic hypotension, saliva, sweat, urine discoloration, NMS with abrupt D/C

Question 8

NMS symptoms

Answer 8

rigidity, fever, autonomic instability, delirium, increased plasma CDK

Question 9

DDIs with L-dopa

Answer 9

DA antagonists (metoclopramide, APS)

Non-selective MAOIs

High protein intake

Iron salts

Pyridoxine