Parkinson's disease (Test 1)

Question 1

Chronically progressive neurodegenerative disease

Answer 1

PARKINSON’S DISEASE

Question 2

PARKINSON’S DISEASE Results from loss of dopaminergic neurons in the __________pars compacta region of the basal ganglia

Answer 2

substantia nigra

Question 3

The presence of _______ is also a consistent feature of parkinson’s disease

Answer 3

Lewy bodies

Question 4

Dopamine does not readily cross the blood brain barrier (bbb). Approaches to therapy have involved _________(precursor of dopamine) or drugs that mimic the actin of dopamine

Answer 4

Levodopa

Question 5

Levodopa Crosses the bbb and is converted to dopamine by __________________

Answer 5

L-amino-acid decarboxylase (dopa decarboxylase enzyme)

Question 6

Levodopa usually administered with a _______________.

Answer 6

peripheral decarboxylase inhibitor (carbidopa or benserazide)

Question 7

Abrupt d/c of levodopa may result in a precipitous return of symptoms of Parkinson’s disease and associated with __________________-like syndrome.
Thus levodopa should be continued through the perioperative period

Answer 7

neuroleptic malignant-like syndrome

Question 8

Inhibition of the peripheral activity of the _________ enzyme greatly increases the fraction of administered levodopa that remains intact to cross the bbb.

Answer 8

decarboxylase

Question 9

Metabolism of Levodopa

Answer 9

metabolized in liver excreted by kidney

Question 10

Most common SE (in first few weeks) with levodopa and dopamine agonists is __________ and ________.

Answer 10

nausea and hypotension

Question 11

What color urine is normal with levodopa?

Answer 11

red or black

Question 12

Levodopa may cause a _____ _____ tests: Test for antibodies in blood stream determining if the immune system is destroying the patient’s own blood cells causing anemia

Answer 12

Positive Coomb’s

Question 13

Drug Interactions Levodopa:

Answer 13

Antipsychotic Drugs:
Butyrophenones and phenothiazines can antagonize effects of dopamine and should not be given to Parkinson’s patients (known or suspected).
Droperidol: causing severe skeletal muscle rigidity and pulmonary edema (may be d/t sudden antagonism of dopamine)
Droperidol as been know to produce a Parkinson’s disease-like syndrome in otherwise healthy patients
Metoclopramide may also interfere with dopamine activity
Monoamine Oxidase Inhibitors:
Can exaggerate PNS and CNS effects of levodopa. Hypertension and hyperthermia are side effects with concurrent administrations
Anticholinergic Drugs: Act synergistically with levodopa to improve certain symptoms of Parkinson’s disease especially tremor
Large doses of anticholinergics can slow gastric emptying such that absorption of levodopa from the GI tract is decreased
Pyridoxine (Vitamin B): in doses as a low as 5 mg can abolish the therapeutic efficacy of levodopa by enhancing the activity of pyridoxine-dependent dopa decarboxylase and thus increasing the metabolism of levodopa in the circulation before it can enter CNS

Question 14

Peripheral Decarboxylase Inhibitors
Allows more levodopa to escape metabolism into dopamine in the peripheral circulation and thus is more available to enter CNS
N/V and cardiac dysrhythmias are diminished or absent
Does not treat abnormal involuntary movements and psychiatric disturbances.

Answer 14

Carbidopa and Benserazide:

Question 15

levodopa and carbidopa in a 10:1 or 4:1

Answer 15

Sinemet

Question 16

levodopa and benserazide in a 4:1 ratio

Answer 16

Madopar:

Question 17

SYNTHETIC DOPAMINE AGONISTS

Do not require transformation or facilitated transport across the bbb.

Answer 17

Bromocriptine and Pergolide (tetracyclic ergot alkaloids)

Pramiperxole, ropinirole, and rotigotine (non ergot alkaloids)

Question 18

Bromocriptine metabolized in _____, excreted in _____.

Answer 18

liver, bile

Question 19

Bromocriptine side effects

Answer 19

Visual and auditory hallucinations
Hypotension
Dyskinesia
These occur more using bromocriptine than levodopa
Asymptomatic increases of serum transaminase and alkaline phosphatase

Question 20

Doxapram moa

Answer 20

Centrally acting analeptic that also acts peripherally on chemoreceptors augmenting breathing efforts.

Question 21

Doxapram use

Answer 21

Used as a temporary measure to maintain ventilation during administration of supplemental O2 to patients with chronic obstructive airway disease who would otherwise rely on hypoxic drive to maintain

Post-operatively has been used to prevent ventilatory depression produced by opioids without altering analgesia

Been shown to be useful in stopping post-op shivering

Question 22

Baclofen moa

Answer 22

Acts as an agonist at GABAB receptors in the dorsal horn of the spinal cord and is often administered for treatment of spastic hypertonia of cerebral and spinal cord origin.
Relieves spasticity by activating G protein-linked presynaptic GABAB receptors that hyperpolarize muscle spindle afferent neurons, thereby decreasing the number and amplitude of excitatory postsynaptic potentials along the dendrites of motor neurons.

Question 23

Baclofen treatment

Answer 23

Flexor spams

Skeletal muscle rigidity associated with spinal cord injury or MS

Question 24

Baclofen:

Therapeutic plasma concentrations _____mg/mL

Answer 24

80-400

Question 25

Baclofen Side Effects:

Answer 25

Sedation
Skeletal muscle weakness
Confusion

Question 26

Baclofen sudden d/c may result in:

Answer 26

Multiple organ system failure
Tachy
Auditory and visual hallucinations
A known case of cardiac arrest has been reported
Vocal cord spasm following abrupt d/c of intrathecal infusion
Coma, depression of ventilation and seizures with overdose
Threshold for initiation of seizures may be lowered in pts with epilepsy
Mild hypotension in awake pts
Bradycardia, hypotension and delayed awakening when general anesthesia is used

Question 27

Dantrolene moa

Answer 27

Exerts antispasmodic effect by decreasing calcium release from sarcoplasmic reticulum

Question 28

Dantrolene Dose

Answer 28

DOSE: 2.5 MG/KG TO MAX 10 MG/KG GIVEN EVERY 5 MINUTES UNTIL EPISODE HAS STOPPED

Question 29

Dantrolene half life

Answer 29

6hrs

Question 30

Dantrolene AFTER EPISODE IS CONTROLLED dose

Answer 30

1 MG/KG IV Q 6 HOURS FOR 24 - 48 HOURS TO PREVENT RELAPSE (MH CAN RECUR WITHIN 24 HOURS AFTER INITIAL EPISODE)

Question 31

Dantrolene side effects

Answer 31

MOST SERIOUS COMPLICATION OF USE: GENERALIZED MUSCLE WEAKNESS THAT MAY RESULT IN RESPIRATORY INSUFFICIENCY OR ASPIRATION PNEUMONIA