Parkinson's Disease: Drugs

Question 1

When should treatment be started and what type of treatment should be used initially?

Answer 1

Treatment should be started when symptoms are disabling.

If younger then start a dopamine receptor agonist.

(Cabergoline, Ropinirole, Bromocriptine)

If elderly, then start levodopa.

Question 2

Name some dopamine receptor agonists.

Answer 2

• Bromocriptine (ergot derived)
• Ropinirole
• Cabergoline (ergot derived)
• Apomorphine

Question 3

What can dopamine receptor agonists cause?

Answer 3

• Pulmonary fibrosis
• Cardiac fibrosis
• Retroperitoneal fibrosis.

Question 4

If someone is on dopamine receptor agonists (bromocriptine, cabergoline), how should they be monitored?

Answer 4

ECHO, ESR, creatine and CXR before treatement.

Monitored closely during treatment.

Question 5

What are some side effects of dopamine receptor agonists?

Answer 5

1. Hotncilaanluis (in the elderly)
2. Ansal ceooinstgn
3. Postural hypotension
4. Imulspe cntoorl ddriseros
5. Eecsivsxe diytmae slononcmee.
6. Fbrsiois of the Lgnus, hraet and roieertetpurnom.

NOTE: Patient should be warned about 4-6.

Question 6

Levodopa is usually mixed with what drug and why?

Answer 6

Carbidopa

Decarboxylase inhibitor (Carbidopa or benserazide)

To prevent peripheral metabolism of levodopa to dopamine.

Question 7

What are some side effects of levodopa?

Answer 7

1. Dkeiynissa
2. “On-off eecfft”
3. Dry mtouh
4. Axeroina
5. Plpiaianttos.
6. Pauotrsl hitepyosnon
7. Pcosyihss
8. Dwrnsoseis

Question 8

Name a monoamine Oxidase-B inhibitor and it’s mode of action?

Answer 8

Selegiline

It inhibits the breakdown of dopamine secreted by the dopaminergic neurons.

Question 9

Name some Catechol-O-Metyl Transferase inhibitors and describe their mode of action.

Answer 9

Entacapone, Tolcapone.

COMT is an enzyme involved in the breakdown of dopamine.

It is an adjunct to levodopa therapy.

Question 10

Why are antimuscarinics useful in Parkinsons disease?

Answer 10

• They are used to treat drug-induced parkinsonism rather than idiopathic Parkinson’s disease.
• They help tremor and rigidity.

Question 11

Name some antimuscarinics used to treat drug-induced parkinsonism.

Answer 11

• Procyclidine
• Benzotropine
• Trihexyphenidyl (Benzhexol)

Question 12

What is the most common psychiatric problem in parkinson’s?

• Tics
• Psychosis
• Mania
• Dementia
• Depression

Answer 12

Depression is the most common psychiatric problem.

Whilst dementia is common in patients with Parkinson’s disease depression is known to exist in around 40%

Psychosis, sleep distrubances may also occur.