What is used in idiopathic Parkinson’s disease to improve motor symptoms?
Levodopa
Outline the pathology of idiopathic Parkinson’s disease
Clinical features of Parkinsonism
Tremor
Rigidity
Brradykinesia
Postural instability
Diagnosis of idiopathic Parkinson’s disease
What is idiopathic Parkinson’s disease?
Progressive neurodegenerative disorder due to loss of substantia nigra dopamine neurones
At what point of loss of pigment in idiopathic Parkinson’s disease do symptoms present?
> 50% loss
Non motor manifestations of idiopathic Parkinson’s disease
Describe Parkinsonian tremor
Low frequency
Pillrolling
At rest
Stops with movement
Describe Parkinsonian rigidity
Lead pipe
Tension all the way through flexion
Describe Parkinsonian gait
What enzyme converts levodopa to dopamine?
Dopa decarboxylase
Outline catecholamines synthesis
L tyrosine > levodopa > dopamine > noradrenaline > adrenaline
Why is levodopa used instead of dopamine to treat idiopathic Parkinson’s disease?
Levodopa crosses the blood brain barrier but dopamine cannot
Pharmacokinetics of levodopa
How is levodopa converted to dopamine?
Describe the formulation of levodopa
Why is levodopa given in combination with peripheral dopa decarboxylase inhibitor?
Advantages + disadvantages of levodopa
Advantages:
- high efficacy
- low side effects
.
Disadvantages:
- loss of efficacy long term due to degeneration of axons
- needs enzyme conversion
- motor complications long term
Side effects of levodopa
Motor complications of long term levodopa
Important drug drug interactions with levodopa
What drugs are used in treatment of idiopathic Parkinson’s disease
Why do COMT inhibitor have no therapeutic effect alone?
Do not cross BBB
What is stalevo?
Combination tablets of COMT inhibitor, levodopa + peripheral dopa decarboxylase inhibitor