Drugs For Movement Disorders CIS

Question 1

List dopamine receptor agonists

Answer 1

Apomorphine
Bromocriptine
Pramipexole
Ropinirole

Question 2

List monoamine oxidase inhibitors

Answer 2

Rasagiline

Selegiline

Question 3

List catechol-O-methyltransferase inhibitors

Answer 3

Entacapone

Tolcapone

Question 4

List antimuscarinic drugs

Answer 4

Benztropine
Biperiden
Orphenadrine
Procyclidine
Trihexyphenidyl

Question 5

72 y/o male complains of 6 month history of left-hand tremor at rest. He also notes a stooped posture, a tendency to drag his left leg when walking, and slight unsteadiness on turning that has progressively worsened over past 4 months. He remains independent in all activities of daily living. Exam reveals hypomimia (flat facies), hypophonia, rest tremor of left arm and leg, mild rigidity in all limbs, and impaired rapid alternating movements in left limbs. Neurologic and general examinations are otherwise normal. CBC is normal.

1. Most likely diagnosis?
A. Huntington disease
B. Parkinson disease
C. Restless leg syndrome
D. Tics
E. Wilson disease

2. Loss of neurons in which region is most likely associated?
3. Levodopa is prescribed. Which agent is most likely prescribed to greatly improve efficacy of levodopa, reduce adverse effect of levodopa, and improve patient’s motor symptoms?
4. Patient is successfully treated for next 3 years. He presents for a regular checkup. Which symptoms most likely?

5. At this appt, an agent that targets catechol-O-methyltransferase is prescribed to treat his presenting symptoms. Which drug is prescribed?
A. Amantadine
B. Apomorphine
C. Bromocriptine
D. Rasagiline
E. Tolcapone

6. Adverse effect of above?

Answer 5

1. B. Parkinson disease
   Huntington disease: no dementia, no psychiatric symptoms, no chorea, diagnosis mid-life
   Restless leg syndrome: no leg symptoms
   Wilson disease: majority diagnosed between 5-35 years of age. Many pts present with liver disease, neurologic symptoms, and psychiatric symptoms
2. Substantia nigra
3. Carbidopa
   DOPA decarboxylas inhibitor that does not cross BBB
   Decreases peripheral metabolism, increases plasma levels, increases half-life, increases levodopa available for entry into brain, decreases daily requirements of levodopa (only 1-3% levodopa actually enters brain unaltered due to BBB and DOPA decarboxylase)
4. Multiple episodes of immobility per day
   Fluctuations in response: wearing off phenomenon (due to dose timing) vs on-off phenomenon (unrelated to dose timing)
5. E. Tolcapone
   COMT inhibitors (tolcapone and entacapone) prolong activity of levodopa by inhibiting its peripheral metabolism, which decreases clearance and increases bioavailability
   Amantadine: antiviral
   Apomorphine and bromocriptine: dopamine agonist
   Rasagiline: MAO inhibitor. This and selegiline prolong activity of levodopa by inhibiting metabolism by MAO (selective for MAO-B)
6. Hepatotoxicity
   Reserved for patients who are experiencing inadequate symptom control or who are not appropriate candidates for other treatments. Pts must provide written consent.

Question 6

55 y/o male with a 3 yr history of Parkinson disease presents with increasing frequency and duration of akinesia. Episodes occur randomly throughout week and last up to 4 hours. He experiences an average of 4-6 episodes per week. Current medications include levodop, carbidopa, and pramipexole.

1. This is an example of?

2. What injectable agent is most appropriate?
A. Amantadine
B. Apomorphine
C. Bromocriptine
D. Rasagiline
E. Trihexyphenidyl

3. Shortly after administration of above, he begins to vomit. Adverse effect is associated with activation of what receptor?

Answer 6

1. On-off phenomenon

2. *B. Apomorphine*
Amantadine: antiviral
Bromocriptine: dopamine agonist
Rasagiline: MAO inhibitor
Trihexyphenidyl: mAChR antagonist

3. Dopamine (D2)
   Apomorphine is a DA agonist