1. Unit 11: Drugs that affect the CNS
Nancy Pares, RN, MSN
NURS 1950
Metropolitan Community College

2. Seizures Abnormal or uncontrolled neuronal discharges in the brain
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 4

5. Figure EEG recordings showing the differences between normal, absence seizure, and generalized tonic–clonic seizure tracings 5

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 Postictal state (post seizure)
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 21

22. 22

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 23

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 24

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 25

26. Pharmacotherapy Illustrated: Model of the GABA Receptor–Chloride Channel Molecules in Relationship to Antiseizure Pharmacotherapy 26

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 benzo’s 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. Nurse’s 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 Client teaching
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

43. Objective 8: Describe common symptoms of Parkinson’s Disease.
Objective 9: Describe the role of dopamine in the body.
Objective 10: name the preparations used to treat Parkinson’s.

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

45. Parkinson’s Disease Second most common CNS disease
Progressive loss of dopamine
Tremor, muscle rigidity
Abnormal movement and posture 45

46. 46

47. Symptoms of Parkinson’s Disease
Symptoms known as parkinsonism
Tremors
Muscle rigidity
Bradykinesia
Postural instability
Affective flattening 47

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 48

49. Cause of Symptoms
Degeneration and destruction of dopamine- producing neurons
Substantia nigra portion of brain
Corpus striatum
Normally controls unconsciousness muscle movement 49

50. Neurotransmitters Dopamine and acetylcholine in corpus striatum
Affect balance, posture
Affect muscle tone, involuntary movement
Absence of dopamine
Allows acetylcholine stimulation 50

51. Drug Therapy for Parkinsonism
Restores dopamine function
Blocks acetylcholine
Extrapyramidal side effects (EPS) 51

52. 52

53. Antiparkinsonism Agents
Restore balance of dopamine and acetylcholine in brain
Dopaminergic drugs
Dopaminergic adjunct agents
Anticholinergics (cholinergic blockers) 53

54. Dopaminergics Restore balance of dopamine and acetylcholine
Dopaminergic examples
Levodopa (Larodopa),
Levodopa and carbidopa (Sinemet) 54

55. Levodopa (Larodopa) Levodopa (Larodopa) is drug of choice
Increases biosynthesis of dopamine within nerve terminals
Effectiveness boosted by combining with carbidopa (Sinemet) 55

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) 56

57. Anticholinergic Agents
Centrally acting
Block acetylcholine
Inhibits overactivity in brain
Used in early stages
Examples
Benztropine mesylate (Cogentin)
Triexyphenidyl hydrochloride (Artane) 57

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) 58

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 59

60. Dopaminergic Agents (continued)
Adverse effects: dizziness, light-headedness, sleep dysfunction, fatigue, nausea, vomiting, constipation, orthostatic hypertension, dystonia, dyskinesia 60

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63. Click here to view an animation on the topic of levadopa.
Levadopa Animation
Click here to view an animation on the topic of levadopa. 63 63

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 64

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66. 66

67. Role of the Nurse: Dopaminergic Drug Therapy
Contraindicated in narrow-angle glaucoma
Monitor for hypotension and tachycardia
Look for symptoms of drug toxicity 67

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 68

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 69

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) 70

71. Obj. 13: define sedative and hypnotic
An agent that calms nervousness, irritability and excitement
Hypnotic
An agent that induces sleep

72. 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.
Results from damage to the motor area of the cerebral cortex
Conditions:
Cerebral palsy
severe head injury, spinal cord injury or lesions
stroke
dystonia

74. Obj. 17: Goals of drug therapy for muscle spasms
Goals of muscle relaxants
Minimize discomfort
Increase ROM
Improve ability to function independently

75. Obj. 18: Name the musculoskeletal relaxants
Centrally acting muscle relaxants
Prototype: cyclobenzaprine (Flexeril)
Mechanism of action
Inhibits upper motor neuron activity
Alters simple spinal reflexes, causes CNS depression
Primary Use
Treat localized spasms
Adverse effects
CNS depression, hepatic toxicity, physical dependence, anticholinergic effects

76. Obj. 18: cont Direct acting antispasmodics
Prototype: dantrolene (Danantrium)
Mechanism of action
Interferes with release of calcium ions in skeletal muscle
Primary use
Relieve dystonias and leg cramps
Adverse effects
Hepatic toxicity, muscle weakness, drowsiness, diarrhea

77. Obj. 19 Nursing process for CNS drugs
Assessment
Monitor pain, LOC, vital signs
Monitor muscle tone, ROM, degree of spasms
Monitor labs
Nursing Dx
Pain
Impaired physical mobility
Risk for injury
Deficient knowledge

78. Obj. 19 cont Goals Decrease pain Increase range of motion (ROM)
Reduce muscle spasms
No adverse effects of drugs
Knowledge of drug regimen