Pharmacology of Parkinson's disease

Question 1

What is the mainstay of treatment for Parkinson’s disease? (Pharm)

State the trade name, ingredients, and the dosage.

Answer 1

L-DOPA and carbidopa, dose 500 to 1500 mg L-DOPA with 250 mg Carbidopa/day

L-DOPA remains by far the most important drug for treating Parkinson’s disease. Combined with the peripheral decarboxylase inhibitor carbidopa as Sinemet, L-DOPA provides useful clinical benefit for 5 to 20 years after diagnosis.

Question 2

Name 2 dopamine receptor agonists.

Answer 2

Pramipexole
Ropinirole

[Bromocriptine]

Largely D2 agonists.

Question 3

Name a drug that facilitates release of endogenous dopamine.

Answer 3

Amantadine

Also produces an NMDA block, presumably by acting as a glutamate antagonist.

[notes explicitly state “glutamate antagonist]

Question 4

Name 3 anticholinergic drugs used in the treatment of Parkinson’s.

Answer 4

1. Trihexyphenidyl
2. Benzotropine
3. Diphenhydramine

**Less used to to sfx

Question 5

Name a MAO inhibitor used in the treatment of Parkinsons’s.

Answer 5

Selegiline.

Question 6

Name 2 COMT inhibitors used in the treatment of Parkinson’s.

What does COMT stand for?

Answer 6

Entacapone
[Tolcapone]

Catechol-o-methyl transferase

Question 7

Pramipexole

Answer 7

Dopamine receptor agonist.

Question 8

Ropinirole

Answer 8

Dopamine receptor agonist.

Question 9

Amantadine

Answer 9

Endogenous dopamine release, NMDA block

Question 10

Trihexyphenidyl

Answer 10

Anticholinergic

Question 11

Benztropine

Answer 11

Anticholinergic

Question 12

Diphenhydramine

Answer 12

Anticholinergic

Question 13

Selegiline

Answer 13

MAO-B inhibitor

Question 14

Tolcapone

Answer 14

COMT inhibitor.

Question 15

Entacapone

Answer 15

COMT inhibitor.

Question 16

What is the average age of onset for Parkinson’s?

What are some environmental risk factors for Parkinson’s mentioned in lecture?

What are some protective factors mentioned in class?

Answer 16

Age 60. Younger onset is more likely to have a genetic underlying cause.

Well water, pesticides, copper/iron exposure are risk factors.

Coffee, tea, nicotine.

Question 17

What do MAO inhibitors and COMT inhibitors do?

Answer 17

MAO - inhibit dopamine breakdown

COMT - inhibit L-dopa and dopamine breakdown

Question 18

What are limiting side effects of anticholinergic agents?

Answer 18

Urinary retention, confusion, drowsiness, and constipation.

Question 19

What are some surgical interventions for Parkinson’s?

Answer 19

DBS - insert into thalamus, GPi, Subthalamic nucleus.

Can surgically remove same structures, imagine this is less done now that DBS can perform the same function reversibly.

Fetal dopamine cell transplantation has also been tried.

Question 20

What are the side effects of L-DOPA?

Answer 20

Long term - dyskinesias

Short term - nausea, hypotension, depression, psychosis

Question 21

What is an important sfx of Dopamine receptor agonists?

Answer 21

Falling asleep (driving).