Antiparkinsonian drugs

Question 1

what is Parkinson’s disease characterized by?

Answer 1

a neurological disorder of impaired voluntary movements

Question 2

what are the impaired voluntary movements caused by?

Answer 2

degeneration of dopaminergic neurons in the substantia nigra of the midbrain

Question 3

causes of Parkinson’s

Answer 3

hereditary
environmental toxins -> irreversible destruction of nigrostriatal dopamine
virally
aging
idiopathic
drugs (antipsychotics + valproate)

Question 4

causes of disruption

Answer 4

imbalance between dopamine & ach (low dopamine & high ach)

Question 5

how much of DA neurons must be removed to be recognized as Parkinson’s

Answer 5

70-80% of Dopamine neurons must be lost to be recognized by Parkinson’s

Question 6

age of onset? which gender gets it more?

Answer 6

55-65 years of age, males more than females

Question 7

symptoms

Answer 7

Bradykinesia
Resting tremors
Rigidity and muscle stiffness
(mask-like face)
Postural instability
Gait disorders
Dysarthria (speech disorders)
dysphagia (swallowing disorders)
dementia (late symptoms).
Death may result from complications of immobility as pulmonary embolism

Question 8

what is bradykinesia

Answer 8

slowness of movement, the difficulty of initiating and continuing movement

Question 9

gait disorder

Answer 9

shuffling and small steps

Question 10

treatment modalities

Answer 10

1- Decrease cholinergic activity → antimuscarinics e.g. benztropine
2- Increase dopamine level:
a. Replacement of missing dopamine e.g. L-dopa.
b. Activation of dopamine receptors e.g. pergolide & bromocriptine.
c. increase the release of stored Dopamine e.g. amantadine.
d. decrease Dopamine degradation e.g. selegiline (MAO b), entacapone