Unit 11: Drugs that affect the CNS

About This Presentation

Title:

Unit 11: Drugs that affect the CNS

Description:

Nancy Pares, RN, MSN NURS 1950 Metropolitan Community College ... – PowerPoint PPT presentation

Number of Views:251

Avg rating:3.0/5.0

Slides: 79

Provided by: ITS51

Category:

more less

Transcript and Presenter's Notes

Title: Unit 11: Drugs that affect the CNS

1
Unit 11 Drugs that affect the CNS

Nancy Pares, RN, MSN
NURS 1950
Metropolitan Community College

2
Obj. 1 Describe the general cause of seizures
and the two major clinical findings associated
with seizures.

Seizures
Abnormal or uncontrolled neuronal discharges in
the brain
affect
Consciousness
Motor activity
Sensation
Symptom of an underlying disorder-not a disease
itself

3
Obj 2 Factors that precipitate seizures

Infectious diseases
Trauma
Metabolic disorders
Vascular diseases
Pediatric disorders
Neoplastic diseases

4
Different etiologies of seizure activity

Most common serious neurologic problem affecting
children
May present as an acute situation, or they may
occur on a chronic basis

Figure 15.1 EEG recordings showing the
differences between normal, absence seizure, and
generalized tonicclonic seizure tracings

6
Drugs as cause of seizures

High dose of local anesthetics
Drug abuse
Withdrawal from alcohol
Withdrawal from sedative-hypnotics

7
Convulsion

Involuntary violent spasm of large muscles of the
face, neck, arms and legs
Not synonymous with seizure

8
Obj. 3 Name and describe major types of
epileptic seizures

Signs and symptoms
Related to the area of the brain with abnormal
activity
Types-based on International Classification
Partial (focal)
Generalized
Special epileptic syndromes

9
Simple partial (focal) seizures

Occur in limited portion of brain
Point of origin abnormal focus or foci
Clients experience
Feeling that is vague
Hallucinations with all senses
Extreme emotions
Twitching of arms, legs or face

10
Complex partial (focal) seizures

Altered levels of consciousness
Involve sensory, motor, autonomic symptoms
Aura commonly precedes seizure
No memory of seizure

11
Generalized seizures

Travel throughout the entire brain
Subcatagories
Absence
Atonic
Tonic-clonic

12
Absence seizures

Common in children
Subtle symptoms
Staring
Transient loss of consciousness
Eyelid fluttering
Myclonic jerks

13
Atonic seizures

Usually last only a few seconds
Characterized by stumbling or falling

14
Tonic clonic

Most common
Usually preceded by aura
Tonic phase
Intense muscle contractions
Hoarse cry at onset
Loss of bowel/bladder control
Shallow breathing

15
Tonic clonic, cont

Clonic phase
Alternating contraction and relaxation of muscles
Postictal state (post seizure)
Drowsiness, disorientation, deep sleep

16
Special epileptic syndromes

Febrile seizures
Myoclonic seizures
Status epilepticus

17
Febrile seizures

Last one two minutes
Tonic clonic motor activity
Common in 3-5 year olds
Occur with rapid rise in body temperature
Affect 5 of all children

18
Myoclonic seizures

Large jerking body movements
Quick contraction of major muscles
Stumbling and falling
Similar to normal infantile Moro reflex

19
Status epilepticus

Medical emergency
Continuously repeating seizure
Common with generalized tonic-clonic
Continuous muscle contractions
May compromise airway
May cause hypoglycemia, hypothermia, acidosis
May produce lactic acid

20
Obj. 4, 5, 6,and 7 (inclusive)

The choice of drug depends upon
Type of seizure
Client history and diagnostic studies
Pathologic process causing seizures

21
Once Medication is Selected

Patient placed on low initial dose
Amount gradually increased
If seizure activity remains, different medication
added in small increments
Newer antiseizure drugs have less adverse side
effects than older drugs
Most cases require only a single drug

22
(No Transcript)
23
New FDA Warnings

Study included patients with epilepsy, bipolar
disorder, psychoses, migraines, and neuropathic
pain
Popular antiseizure examples found to almost
double risk of suicidal behavior and ideation

24
Antiseizure Pharmacotherapy

Goal suppress neuronal activity enough to
prevent abnormal or repetitive firing
Drugs act through three mechanisms
Stimulating an influx of chloride ions
Delaying an influx of sodium
Delaying an influx of calcium

25
Antiseizure Pharmacotherapy (cont'd)

Directed at controlling movement of electrolytes
across neuronal membranes or affecting
neurotransmitter balance
Some drugs act by more than one mechanism

26
Pharmacotherapy Illustrated Model of the GABA
ReceptorChloride Channel Molecules in
Relationship to Antiseizure Pharmacotherapy
27
Barbiturates and GABA Agents

GABA gamma aminobutyric acid
Primary neuro transmitter of brain.
Drugs that potentiate GABA action
Barbiturates
Benzodiazepines
Misc. agents

28
Barbiturates

Prototype phenobarbital (Luminal)
Mechanism of action
Changing the action of GABA
Primary use
Controlling seizures
Adverse effects
Dependence, drowsiness, vitamin deficiencies,
laryngeospasm

29
Benzodiazepines

Prototype diazepam (Valium)
Mechanism of action
Similar to barbiturates, but safer
Primary use
Short term seizure control
Adverse effects
Drowsiness and dizziness

30
Miscellaneous GABA Agents

Prototype valproic acid (Depakene)
Mechanism of action
similar to benzos and barbiturates
Primary use
Adjunct therapy
Adverse effects
Sedation, drowsiness, GI upset, prolonged
bleeding time

31
Hydantoins

Prototype phenytoin (Dilantin)
Mechanism of action
Desensitize sodium channel blockers
Primary use
Treatment of all types of seizures, except
absence seizures
Adverse effects
CNS depression, gingival hyperplasia, skin rash,
cardiact dysrhythmias, and hypotension

32
Phenytoin-like Drugs

Prototype drug valproic acid (Depakene)
Mechanism of action
Desensitize sodium channels
Primary use
Absence seizures
Adverse effects
Limited CNS depression, visual disturbances,
ataxia, vertigo, HA, GI, hepatotoxicity,
pancreatitis

33
Succinimides

Prototype ethosuximide (Zarontin)
Mechanism of action
Suppress calcium influx
Primary use
Absence seizures
Adverse effects
Rare, but include drowsiness, dizziness, lethargy
Rare, but serious lupus, leukopenia, aplastic
anemia, Stevens-Johnson syndrome

34
Nurses role in pharmacological management

Barbiturates
Monitor for liver and kidney function
Category D in pregnancy
Depletion of nutrients
Alcohol and ginko biloba interactions
Client teaching
Use reliable contraception
Immediately report pregnancy
Report excessive bleeding,drowsiness, bone pain
Avoid alcohol and gingko biloba

35
Benzodiazepines-schedule IV drug

Monitor for drug abuse potential
Pregnancy risk (category D)
Contraindicated in narrow angle glaucoma
Liver and kidney function monitored
Respiratory depression
In event of overdose
Give flumazenil (Romazicon)

36
Status epilepticus

Give IV valium and ativan
Do not mix with other drugs in IV line
Client teaching
Avoid ETOH, OTC drugs, herbal preps, nicotine,
driving and hazardous activities
Rebound seizures if d/c abruptly
Take with food
These drugs most often used illegally

37
Hydantoin and Phenytoin-like drugs

Monitor serum drug levels, liver and kidney
function
Monitor for bleeding disorders
Fatal hepatotoxicity can occur
Contraindicated
Hx of heart block or seizures due to low BS
Client teaching
Routine labs report s/s of toxicity, bleeding,
pregnancy, hypoglycemia

38
Succinimides

Monitor for liver and kidney function
Pregnancy category C
Adverse reactions
Drowsiness, HA, euphoria, n/v, weight loss, abd.
Pain
Life threatening reactions
Mental depression with suicide intent
Blood dyscrasias and Stevens-Johnson syndrome

39
Succinimides

Symptoms of overdose
CNS depression, stupor, ataxia, coma
Client teaching
Report mood changes or suicidal thoughts
Avoid driving and hazardous activities
Take with food
Do not stop abruptly
Report weight loss and anorexia

40
General client teachings for epilepsy

Start with smallest dose of med
Add additional drugs, if needed
Monitor serum drug levels
Withdrawal of meds
Seizure free for three years
Done gradually
Resume meds if seizures return
Knowledge of rebound seizures

41
Nursing diagnosis for epilepsy

Disturbed sensory perception RT seizure activity
Risk for injury RT seizure activity
Deficient knowledge RT disease/drugs
Noncompliance RT drug regime
Noncompliance RT serum lab testing

42
Goals in epilepsy treatment

Absence/reduction in number of seizures
No injury during seizure
Understanding of disease
Understanding of drug regimen
Compliance with lab testing

Objective 8 Describe common symptoms of
Parkinsons Disease.
Objective 9 Describe the role of dopamine in
the body.
Objective 10 name the preparations used to
treat Parkinsons.

Objective 11 describe the role of the
anticholinergic drugs in the treatment of
Parkinsons
Objective 12 Apply nursing process as it relates
to the care of the client with Parkinsons and
accompanying drug therapy.

45
Parkinsons Disease

Second most common CNS disease
Progressive loss of dopamine
Tremor, muscle rigidity
Abnormal movement and posture

46
(No Transcript)
47
Symptoms of Parkinsons Disease

Symptoms known as parkinsonism
Tremors
Muscle rigidity
Bradykinesia
Postural instability
Affective flattening

48
Health Problems in Parkinsons Patients

Primarily affects muscle movement
Patients often experience other health issues
Anxiety, depression
Sleep disturbances
Dementia
Autonomic nervous system disturbances

49
Cause of Symptoms

Degeneration and destruction of
dopamine-producing neurons
Substantia nigra portion of brain
Corpus striatum
Normally controls unconsciousness muscle movement

50
Neurotransmitters

Dopamine and acetylcholine in corpus striatum
Affect balance, posture
Affect muscle tone, involuntary movement
Absence of dopamine
Allows acetylcholine stimulation

51
Drug Therapy for Parkinsonism

Restores dopamine function
Blocks acetylcholine
Extrapyramidal side effects (EPS)

52
(No Transcript)
53
Antiparkinsonism Agents

Restore balance of dopamine and acetylcholine in
brain
Dopaminergic drugs
Dopaminergic adjunct agents
Anticholinergics (cholinergic blockers)

54
Dopaminergics

Restore balance of dopamine and acetylcholine
Dopaminergic examples
Levodopa (Larodopa),
Levodopa and carbidopa (Sinemet)

55
Levodopa (Larodopa)

Levodopa (Larodopa) is drug of choice
Increases biosynthesis of dopamine within nerve
terminals
Effectiveness boosted by combining with carbidopa
(Sinemet)

56
Dopaminergic Adjunct Agents

Inhibit enzymes
Example Tolcapone (Tasmar)
Activate dopamine receptors (dopamine agonists)
Example Ropinirole (Requip)
Cause dopamine release from nerve terminals
Example Amantadine (Symmetrel)

57
Anticholinergic Agents

Centrally acting
Block acetylcholine
Inhibits overactivity in brain
Used in early stages
Examples
Benztropine mesylate (Cogentin)
Triexyphenidyl hydrochloride (Artane)

58
Catechol-O-Methyl Transferase (COMT) Inhibitors

Reduce requirement for L-dopa
Increase concentration of existing dopamine
improve motor fluctuations
Examples
entacapone (Comtan)
tolcapone (Tasmar)

59
Dopaminergic Agents

Prototype drug levodopa (Larodopa)
Mechanism of action Increases biosynthesis of
dopamine within nerve terminals
Primary use to restore dopamine function or
stimulate dopamine receptors within the brain

60
Dopaminergic Agents (continued)

Adverse effects dizziness, light-headedness,
sleep dysfunction, fatigue, nausea, vomiting,
constipation, orthostatic hypertension, dystonia,
dyskinesia

61
(No Transcript)
62
(No Transcript)
63
Levadopa Animation

Click here to view an animation on the topic of
levadopa.

64
Anticholinergic Agents

Prototype drug benztropine mesylate (Cogentin)
Mechanism of action block acetylcholine inhibit
overactivity in brain
Primary use in early stages of disease
Adverse effects dry mouth, blurred vision,
photophobia, urinary retention, constipation,
tachycardia, glaucoma

65
(No Transcript)
66
(No Transcript)
67
Role of the Nurse Dopaminergic Drug Therapy

Contraindicated in narrow-angle glaucoma
Monitor for hypotension and tachycardia
Look for symptoms of drug toxicity

68
Dopaminergics Client Teaching

Increase fiber and fluids
Avoid food and drugs high in pyridoxine
May take several months for full effect
Abruptly stopping the drug may cause Parkinsonism
crisis

69
Anticholinergics Client Teaching

Relieve dry mouth with frequent drinks or
sugarless hard candy
Take with food or milk to prevent GI upset
Avoid alcohol
Wear dark glasses avoid bright sunlight
Do not stop taking abruptly

70
Nursing Considerations with AChE Inhibitors

Assess baseline vitals
Monitor for hypotension
Monitor for change in mental status or mood
Monitor for dizziness, insomnia, anorexia
Clients with narrow-angle glaucoma should not
take revastigmine (Exelon)

71
Obj. 13 define sedative and hypnotic

Sedative
An agent that calms nervousness, irritability and
excitement
Hypnotic
An agent that induces sleep

Objective 14 describe actions, use and s/e of
barbiturates (covered earlier)
Objective 15 identify the commonly used
barbiturates and benzo (covered earlier)

73
Obj. 16 Name the conditions that may cause
muscle spasticity.