Drugs for Parkinson's Flashcards

1
Q

A progressive disorder of movement that occurs most commonly in the elderly

A

Parkinson’s Disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The result of loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc) in the basal ganglia

A

Parkinson’s Disease (PD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In PD dopamine is progressively lost, the effect of acetylcholine is relatively

A

Increased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Parkinson’s Disease is diagnosed at an advanced stage of approximately

A

80% cell loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In PD there is a late appearance of symptoms - probably because of adaptive increase in dopamine receptors until the effect

A

“Max out”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

MPTP is metabolized to the free radical, MPP+, which produces oxidative stress resulting in

A

Cell Death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Lead to the hypothesis that metabolism of dopamine could lead to the same effect via production of free radicals

A

MPTP Toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The goal of treatment in PD is to facilitate

A

Dopaminergic Neurotransmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The single most effective agent in treatment of PD

A

Levodopa (L-Dopa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Is normally synthesized from L-tyrosine

A

L-Dopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

L-dopa is largely inert and unlike dopamine, it can cross the

A

Blood-brain barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The rate and extend of Levodopa absorption is dependent upon the rate of gastric emptying and

A

pH of gastric juice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Absorbed rapidly from small intestine by active transport system

-Competitive with aromatic amino acids

A

L-Dopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

High protein meal will delay absorption and reduce peak plasma concentration of

A

L-Dopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The peak plasma concentration of L-Dopa is reached 1-2 hours after oral dose and the plasma half-life is

A

1-3 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

An L-aromatic amino acid decarboxylase inhibitor

A

Carbidopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Increases the fraction of levodopa that remains unmetabolized and available to enter the CNS

-Does not itself penetrate the blood-brain barrier

A

Carbidopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Allows reduced dosage of levodopa which reduces peripheral side effects

A

Carbidopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

A Carbidopa + Levodopa combo drug with a 1:4 and 1:10 ratio of carbidopa : levodopa

A

Sinemet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

If Levodopa is given without peripheral decarboxylase inhibitor (carbidopa) then 80% of patients experience

A

Anorexia, Nausea, and Vomiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Combination with carbidopa reduces GI effects to occurrence in

A

20% of patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Can also cause arrhythmias and postural hypertension

A

L-Dopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Markedly accentuates levodopa actions and may precipitate a life-threatening hypertensive crisis

A

Administration with nonspecific MAO inhibitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Enhances extracerebral metabolism of levodopa

A

Pyridoxine (B6)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Accenuate peripheral effects of L-dopa and can cause hypertensive crisis

A

MAO-A inhibitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

L-dopa is contraindicated in

A

Psycotic patients and patients with angle-closure glaucoma and active peptic ulcer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What percentage of patients will experience response fluctuations after 5 years of L-dopa therapy?

A

50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What percentage of patients will experience response fluctuations after 15 years of L-dopa therapy?

A

70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Long term use of L-dopa can result in an increase in the side effects of

A

Dyskinesias and psychiatric disturbances

30
Q

In early PD, the duration of the beneficial effects of levodopa exceeds the plasma lifetime of the drug, because the nigrostriatal dopamine system retains some capacity to

A

Store and Release Dopamine

31
Q

After the long-term use of levodopa therapy this “buffering“ capacity is lost, and the patient’s motor state may fluctuate dramatically with each dose of levodopa. This is called the

A

Wearing Off Phenomenon

32
Q

Each dose of levodopa effectively improves mobility for 1-2 hours, but symptoms return rapidly at the end of the

A

Dosing Interval

33
Q

Patients fluctuate rapidly between having no apparent effects of medication (“off”) and having effects of medication (“on”)

A

The unpredictable O/Off phenomenon

34
Q

Off-periods of marked akinesia alternate over the course of a few hours with on-periods of improved mobility, but often of marked

A

Dyskinesia

35
Q

For severe off-periods if not responding to other measures, we can use

A

Apomorphine

36
Q

What are the two COMT inhibitors used to treat PD?

A

Tolcapone and entacapone

37
Q

Has central and peripheral effects

A

Tolcapone

38
Q

Has peripheral effects only

A

Entacapone

39
Q

Adjunct to levodopa/carbidopa allowing reduction of levodopa dose

A

COMT inhibitors

40
Q

Prolongs plasma half-life of levodopa and increases availability of levodopa to brain

A

Inhibition of COMT

41
Q

Approved for patients with late PD who have developed response fluctuations

A

COMT inhibitors

42
Q

Concurrent use with a non-specific MAO inhibitor could severely limit metabolism of levodopa and is contraindicated

A

COMT inhibitors

43
Q

Can cause an increase in aminotransferase and transaminase activity which results in hepatotoxicity

A

Tolcapone

44
Q

Is not associated with hepatotoxicity

A

Entacapone

45
Q

Are secondary pharmacologic therapies of PD

A

Dopamine agonists like pramipexole, ropinrole, bromocriptine, and pergolide

46
Q

Agonists selectively affecting certain (but not all) dopamine receptors may have more limited adverse effects than

A

Levodopa

47
Q

A D2 agonist that is an ergot derivative

A

Bromocriptine

48
Q

A non-ergot derivative D2 agonist

A

Ropinirole

49
Q

A non-ergot derivative D3 agonist

A

Pramipexole

50
Q

Could be used as monotherapy in patients with mild disease

  • Well absorbed orally
  • Plasma hlf life of 3-7 hours
A

Bromocriptine

51
Q

Has similar affects to levodopa but more severe hallucinations than with levodopa alone

A

Bromocriptine

52
Q

Metabolized by CYP1A2, so drugs that are metabolized by the liver may significantly reduce clearance

A

Ropinirole

53
Q

Excreted largely unchanged in urine

A

Pramipexole

54
Q

Has the RARE side effect of uncontrollable tendency to fall asleep at inappropriate times; requires discontinuation of medication

A

Ropinirole and pramipexole

55
Q

Administered as a once-daily transdermal patch allowing continuous absorption leading to less serum fluctuation as compared to oral administration several times a day

A

Rotigotine

56
Q

In addition to producing adverse side effects seen with other DA receptor agonists, application site reactions (erythema [redness] and pruritis [itching]) were reported in 37% of patients in clinical studies

A

Rotigotine

57
Q

Available as a subcutaneous injection to treat “off” episodes in patients with advanced PD

-Mostly interacts with D2 receptors

A

Apomorphine

58
Q

Rapidly taken up in the brain leading to clinical benefit that begins within 10 min of injection

A

Apomorphine

59
Q

Causes emesis (vomiting/nausea) and requires pretreatment with antiemetic trimethobenzamide 3 days before initial treatment and continued for at least 2 months of therapy, if not indefinitely

A

Apomorphine

60
Q

Contraindicated with antiemetics of the 5HT3 receptor class. Causes severe hypotension and loss of consciousness

A

Apomorphine

61
Q

Metabolizes dopamine selectively

A

MAO-B

62
Q

Metabolizes norepinephrine, serotonin, and dopamine; also found in liver and GI tract

A

MAO-A

63
Q

Irreversible MAO-B inhibitor => B selective at 10 mg/day or less (at higher doses also inhibits MAO-A)

A

Selegiline

64
Q

Retards breakdown of dopamine in striatum without inhibiting peripheral metabolism of catecholamines

A

Selegiline

65
Q

Should not be taken together with analgesic meperidine - stupor, rigidity, agitation, and hyperthermia (mechanism is unknown), tramadol, methadone, cyclobenzaprine, St. John’s wort

A

Selegiline

66
Q

More selective MAO-B inhibitor than selegiline

-Does not produce amphetamine metabolites

A

Rasagiline

67
Q

Retards breakdown of dopamine in striatum without inhibiting peripheral metabolism of catecholamines

A

Rasagiline

68
Q

Studies suggest that rasagiline and selegiline might have a

A

Neuroprotective effect

69
Q

Provide neuroprotection by reducing the oxidation of dopamine

A

Selegiline and Rasagiline

70
Q

Mechanism is unclear but may cause:

  • Increase in dopamine release
  • Blocking of dopamine reuptake
  • Increase in dopamine synthesis
A

Amantidine (antiviral)

71
Q

May favorably influence bradykinesia, rigidity, and tremor

-It also has antidyskinetic properties

A

Amantidine

72
Q

Amantidine overdose may cause acute toxic

A

Psycosis