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

5. Figure 15.1 EEG recordings showing the differences between normal, absence seizure, and generalized tonic–clonic 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

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 Receptor–Chloride 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 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 • 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

47. Symptoms of Parkinson’s 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