Post on 12-Jan-2016
CNS – ANTIEPILEPTIC DRUGS Compare and contrast the terms seizure, convulsion
and epilepsy.
Discuss the indications for antiepileptic therapy (AED).
Compare and contrast the first line drugs of choice for AED.
Discuss the nursing process related to the care of the patient receiving AEDs in acute and chronic situations.
CNS – ANTIEPILEPTIC DRUGSINTERNATIONAL CLASSIFICATION OF
SEIZURES
Partial Seizures – short alterations of consciousness; repetitive unusual movements (chewing or swallowing); psychologic changes; confusion
Simple Seizures – No impaired consciousness; motor symptoms of face, arm or legs; hallucinations of sight, hearing, or taste; tingling sensation; ANS changes; personality changes
Complex Seizures – Impaired consciousness; memory impairment; behavioral effects; purposeless behaviors; aura, unreal feelings, bizarre behavior
Generalized Seizures – Temporary lapses in consciousness; staring off into space; rhythmic movements of eyes, head, or hands; may have tonic, clonic, myoclonic, atonic, or tonic-clonic seizures; brief loss of consciousness without confusion; head drop or falling down symptoms
CNS – ANTIEPILEPTIC DRUGSSYNDROME OF CNS
DYSFUNCTION
Convulsion – Involuntary spasmodic contractions of any or all voluntary muscles throughout the body, including skeletal and facial muscles. Postictal state
Seizures – Brief episode of abnormal electrical activity in the nerve cells of the brain -- detected on EEG
Epilepsy – Chronic, recurrent pattern of seizures
CNS ANTIEPILEPTIC DRUGS /ANTICONVULSANT
DRUGS Terms overlap and are used
interchangeably to achieve the goal of maintaining a reasonable quality of life.
Antiepileptic Drugs: management of all types of epilepsy, not just convulsions (AED Therapy)
Anticonvulsant Drugs: used to prevent the seizures typically associated with epilepsy.
CNS – ANTIEPILEPTIC DRUGSMECHANISM OF ACTION
ION Theory – movement of K+, Na+, Ca+, Mg+:
Stabilizes neurons: from becoming hyperexcited prevents excessive impulses to adjacent neurons
1. Increase threshold of activity in the motor cortex
Makes it more difficult to excite; reduces response
2. Depress the seizure discharge from its origin
Suppress transmission of impulses from one nerve to the next
3. Decrease the speed of nerve impulse conduction within a given neuron
CNS – ANTIEPILEPTIC DRUGSINDICATIONS
Prevention or control of seizure activity Long-term maintenance treatment of epilepsy Acute treatment of convulsions and status
epilepticus Status epilepticus: common seizure disorder –
life-threatening emergency characterized by tonic-clonic convulsions that occur in succession.
Loss of consciousness, hypotension, hypoxia, cardiac dysrhythmias – brain damage and death may quickly result
Once controlled, long term therapy is begun to prevent future seizures
Brain Surgery - Head injuries = prophylactic AED Therapy
CNS – ANTIEPILEPTIC DRUGSCONTRAINDICATIONS
Known drug allergy
Pregnancy – consider risks to mother & infant if untreated
CNS – ANTIEPILEPTIC DRUGSDRUGS OF FIRST CHOICE
AED Therapy Therapeutic Level (mcg/mL)
Adverse Effects
carbamazepine (Tegretol)
3-14 N/V; drowsiness; dizziness; orthostatic hypotension; hypertension; dyspnea; edema; nephrotoxicity; hepatotoxicity; blood dyscrasias; dermatologic reactions
phenytoin (Dilantin)
10-20 Cardiac dysrhythmias; hypotension; N/V indigestion; sedation, drowsiness, dizziness, blurred vision, fatigue, lethargy; confusion; gingival hyperplasia; hyperglycemia; blood dyscrasias; hepatoxicity; dermatologic reactions
primidone (Mysoline)
5-12 Sedation; drowsiness; dizziness; blurred vision; blood dyscrasias; paradoxical excitability
valproic acid (Depakote)
50-100 Drowsiness; N/V; tremor; weight gain; transient hair loss; blood dyscrasias; hepatotoxicity; pancreatitis
CNS – ANTIEPILEPTIC DRUGSTreatment of Status Epilepticus
AED Therapy Dose mg/kg
Onset Adverse Effects
diazepam (Valium)
0.3-0.5
3-10 mins Apnea, hypotension, somnolence
Fosphenytoin (Cerebyx)
15-20 15-30 mins
Cardiac dysrhythmias, hypotension
Lorazepam (Ativan)
0.05-0.1
1-20 mins Apnea, hypotension, somnolence
Phenobarbital 15-20 10-30 mins
Apnea, hypotension, somnolence
Phenytoin (Dilantin)
15-20 5-30 mins Cardiac dysrhythmias, hypotension
CNS – ANTIEPILEPTIC DRUGSBENZODIAZEPINES
Actions Not fully understood May enhance the inhibitory effects of GABA in postsynaptic
clefts between nerve cells Uses
Diazepam (Valium), clonazepam (Klonopin), clorazepate (Tranxene), lorazepam (Ativan) Diazepam - drug of choice for status epilepticus
must be given intravenously -- slowly never mixed with any other medication
Therapeutic outcomes Reduced frequency of seizures, reduced injuries Minimal adverse effects from therapy
CNS – ANTIEPILEPTIC DRUGSHYDANTOINS
Actions – mechanism unknown phenytoin (Dilantin) – most commonly used ethotoin (Peganone) fosphenytoin (Cerebyx)
Uses Anticonvulsants used to control tonic-clonic seizures CAUTION:
Phenytoin must be administered slowly Do not mix with other medications in the same syringe Dilute only with 0.9% NaCl to avoid precipitation Infuse slowly <150mg/min
CAUTION: toxicity may cause nystagmus CAUTION: infiltration causes sloughing of tissue
Therapeutic outcomes Reduced frequency of seizures, reduced injuries Minimal adverse effects from therapy
CNS – ANTIEPILEPTIC DRUGSCARBAMAZEPINE
Actions -- carbamazepine (Tegretol) Blocks up the reuptake of norepinephrine Decreases release of norepinephrine and rate of
dopamine and GABA turnover Mechanisms of action as anticonvulsant are
unknown Uses
Used in combination with other anticonvulsants to control tonic-clonic seizures
Not effective for myoclonic or absence seizures Should not be given with grapefruit – increased
levels of the AED Therapeutic outcomes
Reduced frequency of seizures, reduced injuries Minimal adverse effects from therapy
CNS – ANTIEPILEPTIC DRUGS SUCCINIMIDES
Actions ethosuximide (Zarontin), methsuximide (Celontin)
Mechanism of action unknown
Uses To control absence (petit mal) seizures
Therapeutic outcomes Reduced frequency of seizures, reduced
injuries Minimal adverse effects from therapy
CNS – ANTIEPILEPTIC DRUGS TOPIRAMATE
Actions topiramate (Topomax) Mechanisms of action are unknown May prolong blockade of sodium channels,
enhance activity of GABA, and antagonize certain neurotransmitter receptors
Uses Used in combination with other anticonvulsants
to control tonic-clonic seizures Prevention of migraine headaches
Therapeutic outcomes Reduced frequency of seizures and injuries Minimal adverse effects from therapy
CNS – ANTIEPILEPTIC DRUGS PRIMIDONE
Actions primidone (Mysoline) Metabolized into phenobarbital and PEMA - both
active anticonvulsants Exact anticonvulsant mechanism of action is
unknown
Uses Used in combination with other anticonvulsants
to treat tonic-clonic seizures
Therapeutic outcomes Reduced frequency of seizures and injuries Minimal adverse effects from therapy
CNS – ANTIEPILEPTIC DRUGSGABAPENTIN
Actions gabapentin (Neurontin) Mechanisms of action are unknown Does not appear to enhance GABA
Uses Used in combination with other anticonvulsants
to control partial seizures
Therapeutic outcomes Reduced frequency of seizures Minimal adverse effects from therapy Also used for pain reduction – shingles, peripheral
neuropathy – nerve pain
CNS – ANTIEPILEPTIC DRUGSNURSING IMPLICATIONS
Nurses may play an important role in diagnosis and treatment
Comprehensive history – allergies/medication reconciliation Describe seizures – precipitating events,
duration/frequency, intensity of the seizure activity, postictal behavior – observe & record
Safety – positioning – assist pt during seizure, proper supplies Medication administration guidelines – specific for IV meds
Lab values – check therapeutic blood levels on admission Patient and family support: discuss lifestyle and feelings with
patient
CNS – ANTIEPILEPTIC DRUGSPATIENT EDUCATION
Medication: adherence to prescribe regimen Do not Stop Abruptly – Life Time Treatment - Rebound
Convulsions Medic Alert Bracelet Protective environment Driving – physician prescription/State laws Sedating effects of the drugs – may decrease with time
Avoid alcohol & cigarettes Photosensitivity with certain AEDs – sunscreen &
protective clothing Avoid stimulants Oral hygiene – hyperplasia
CNS – ANTIEPILEPTIC DRUGSREVIEW
When caring for a patient with epilepsy who was hospitalized and successfully treated for status epilepticus, a precaution that the nurse institutes includes:
a. placing oxygen and suction equipment at the bedside. b. assigning an assistant to stay with the patient at all
times. c. keeping an airway available to insert as needed. d. instructing the patient to stay in bed and call for
assistance to go to the bathroom.
CNS – ANTIEPILEPTIC DRUGSREVIEW
A nurse witnesses a patient with a seizure disorder as he suddenly jerks his arms and legs with tonic-clonic type movement, falls to the floor, temporary loss of consciousness, which he regains immediately. The type of seizure demonstrated by this patient and that the nurse documents is:
a. atonic seizure b. myoclonic seizure c. complex partial seizure with automatisms d. generalized seizure