Parkinson's - Block 1 Flashcards
What is the problem with PD?
Low dopamine from low producing neurons
-> less instructions to the brain -> motor symptoms
What is the mechanism of dopamine?
- Produced by neurons in the substantia nigra
- Activation of DR signals the motor cortex
- Smooth, coordinated function of body muscles and movement
*Dopamine gives the brain instructions to move
What are the sx of PD?
Tremor
Rigidity
Akinesia/Bradykinesia
Postural instability
What is the most common sx of PD? Most common type?
Tremor; pill rolling
Occurs at rest
How occurs during rigidity?
Stiffness and pain with alterations of motion
What is Akinesia/Bradykinesia?
Absence or slowness of movement and difficulty to move
* Decreased dexteritity
What is postural instability?
- Shuffling walk
- Stooped posture
- Unable to recover balance
- Risk of falling
Other motor sx of PD?
Falls
Freezing
Dysphagia
Micrographia
Slurred speech
Drooling
Reduced voice volume
Dystonia
Difficulty rising from a seated position
Non motor sx of PD?
Hypotension
Bladder dysfunction
Sexual dysfunction
Sleep disturbances
Depression
Anxiety
Psychosis/hallucinations
Cognitive impairment
Decreased sense of smell
How do we diagnose PD?
- Presence of bradykinesia and at least 1 other TRAP symptom
- Other conditions have been ruled out
- Presence of 3 supportive findings:
* Asymmetry of motor features
* Unilateral onset
* Resting tremor
* Progressive disorder
* Responsive to dopaminergic therapy
What does it feel like for a PD patient?
Put yourself in the patient’s shoes.
What can we do about PD?
Replace dopamine
How do we replace dopamine? Tx for PD
Give dopamine (precursor): Sinemet
Give something to preserve dopamine: COMT Inhibitors, MAO-B Inhibitors
Give something that acts like dopamine: Dopamine Agonists
Give drugs to treat specific symptoms: Anticholinergics, Amantadine, Adenosine A2A Antagonists
What are the first line agents for PD?
- MAO-B Inhibitors
- Dopamine Agonists
- Sinemet
Sinemet
Generic, Indication, ADR, CI, Counseling
Carbidopa-Levodopa
Indication: Bradykinesia and rigidity are predominant, patient is elderly or has cognitive impairment
* prevents peripheral conversion of levodopa
ADR: GI, orthostasis, dz, psych, dark body fluids, dyskinesias, wearing off phenomenon
CI: MAOI use within 14 days, narrow angle glaucoma
Counseling: Do not DC abruptly
* Best absorbed on an empty stomach (avoid iron and high protein foods)
* Don’t crush or chew
* Dry powder levodopa inhaler may be used for breakthrough symptoms
What is the on/off phenomenon?
Fluctuations in movement sx:
* On: good movement
* Off: poor movement
Wearing off is the worsening sx prior to the next dose of med
* Short half-life of levodopa and decline in the ability of the brain to store dopamine
What are the tx for wearing off sx?
- Give Sinemet more frequently (reduce dosing interval)
- Give IR formulation on empty stomach (consistent absorption)
- Add COMT inhibitor, MAO-B inhibitor, or DA to extend action of Sinemet
- Add ER formulation