Flashcards in Psyc ppt (Part 2) Deck (40):
1
What is the pathological finding of Parkinson's?
Degeneration of the neurons
2
The degeneration of Neurons originate where in the Brain
The substantia nigra of the midbrain and terminate in the basal ganglia
3
Name the 2 most reliable and effective drugs to treat Parkinson's
Levodopa and Carbidopa
4
Levadopa crosses the blood brain barrier and is converted by what enzyme ______into what?
L-aromatic amino acid decorboxylase
Dopamine
5
Does dopamine cross the BBB?
NO
6
Levadopa works for Parkinson's disease because it is a ________ to _______ and is converted upon crossing the BBB
precursors
Dopamine
7
Does Carbidopa cross the BBB?
NO
8
Carbidopa is classified as a ________ ________ ?
decarboxylase inhibitor
9
Carbidopa inhibits decarboxylase in the Liver, Kidneys and GI tract and prevents the breakdown of _________?
Levadopa (Carbidopa just prevents Levadopa from being broken down before it crosses the BBB)
10
First symptoms to improve with the use of Levodopa/Carbidopa are?
rigidity and bradykinesia late improvement is the tremors
11
Levodopa/Carbidopa side effects
NV and anorexia D/T activation of the chemoreactive trigger zone in the medulla oblangata
orthostatic hypotension
Cardiac arrythmias D/T Beta adrenergic dopamine stimulation
12
Long term therapy Side Effects
Abnormal Choreiform movements of the limbs and hands, trunk and tongue.
serious mental disturbances such as psychotic episodes and a need for a 1 week drug holiday
13
Levodopa/Carbidopa contraindications
MAO Inhibitors
narrow angle glaucoma
cardiac arrythmias
recent MI
Phenothiazines, butrophenones and reserpine can cause extrapryamidal symptoms
14
Selegiline first line drug for parkinsons before moving to levodopa by?
Enhancing endogenous dopamine
15
Interacts with TCA's causing
Fever agitation deilerium and coma
16
Belladonna Alkaloids
Used in mild cases
combats tremors and dystonia
17
Antihistamines like benadryl
Can be used to control minor tremors in the elderly
18
What % of people respond favorably to Dopamine agonists
only 20-30%
19
Names of Dopamine agonists
Bromocriptine (parlodel), Pergolide (permax)
20
Dopamine agonists side effects are
Anorexia and Nausea due to stimulation of the Chemotatic trigger Zone (CTZ)
21
Anesthetic Implications
-Have Pt take meds preoperatively effects last 6-12 hrs
-Avoid Phenothiazines, butyrophenones, metoclopramide
-Muscle rigidity may impede mask ventilation
-Increased aspiration risk
-Intravascularly volume depleted
22
Anesthetic Implications
-Normal response to muscle relaxants
-Increased risk of post op laryngospasm
-violent tremors on emergence
- No ephedrine in taking Deprenyl
-Ketamine can cause exaggerated sympathetic response
-Potential hyperkalemic response to Sucs
23
Anesthetic Implications
-Skeletal muscle tremor may mimic VFIB on ECG
-May have diminished reserve due to poor exercise tolerance
-Muscle relaxants will relax even the most rigid of patients
24
Anticonvulsants _______ the Seizure threshold
Raise
25
Only ____ % of Pts become SZ free on meds
40%
26
______% of Pts get no benefit from currently avalilable meds
20%
27
Anticonvulsants MOA
Inhibition of neuronal Na+ channels in hyperexcitable cells
Disinhibition may increase SZs
Reduction in GABA increases SZs
28
Anticonvulsants Classes
I-IV based on MOA
29
Type I
Blocks sustained high frequency repetitive firing by enhancing Na+ channel inactivation
-Phenytoin
-Carbamazepine
30
Type II
Multiple actions: enhances GABA inhibition reduces T calcium currents, possibly blocks SRF
-Valproic Acid
-Benzos
-Phenobarbital
31
Type III
Blocks T calcium currents only
-Trimethadione
32
Type IV
only enhances GABA inhibition
-Gabapentin
33
Na+ Channel blocking agents such as
Dilantin used for general tonic clonic and partial SZ
34
Dilantin adverse effects
Overdose- nystagmus, ataxia, vertigo, diplopia
Common- enlarged lips and nose, gingival hyperplasia
idiosyncratic- dermatitis, hepatic necrosis
35
Carbamazepine (Tegretol)
Used for tonic clonic and absent SZ
common SE id drowsiness
Increases metabolism in other anticonvulsants
36
Barbiturated
Increases GABA inhibition
main SE sedation and disturbance in cognitive function
37
Valproic Acid
Blocks Na+ channels and increases GABA in the brain
SE hepatotoxic and Fetal neural tube defects
38
Benzos
interacts with GABA and causes sedation with a rapid development of tolerance
39
Phenytoin
resistant to NDNMB
causes decreased duration of muscle relaxants
rate of administration is 25-50 mg / min to avoid hypotension
Stevens-Johnson syndrome
40