Pharm #4 Flashcards
Seizure disorder
Epilepsy
Abnormal electric discharges from cerebral neurons
Seizure disorder
Seizure disorder Characteristics
Loss of consciousness
Involuntary, uncontrolled movements
Seizure disorder Causes
Idiopathic
Secondary
Isolated seizures
Neurological disorder
Epilepsy
____ of the seizures are unknown reason
75% Epilepsy
____ related to brain injury, trauma, anoxia, infection, cerebral vascular disorders (Stroke)
25% Epilepsy
Chronic condition lasting a lifetime-
epilepsy, long term tx
If seizure nonrelated to epilepsy
electrolyte imbalance and hypoglycemia
International Classification of Seizures
Generalized and Partial
Generalized seizure definition
Both hemispheres of the brain
Types of Generalized Seizures
Tonic-Clonic (Grand-Mal)
Absence (petit mal)
Tonic-Clonic (Grand-Mal)
Most common generalized alternating muscle spasms, extremities jerking, tonic phase of the muscles contracting, colonic phase spasming and jerking.
Absence (petit mal)-
seen in children, causes sudden and brief loss of consciousness
Partial Seizure Definition
One hemisphere of the brain, can progress into generalized seizures
Types of Partial Seizure
Simple Partial and Partial complex
Simple Partial-
No loss of consciousness
Partial complex-
Loss of consciousness
Antiseizure Drugs
Anticonvulsants or antiepileptic drugs
Antiseizure Drugs Basic Action:
Stabilize nerve cell membranes
Suppress abnormal electric impulses in cerebral cortex
Antiseizure Drugs Specific Types of Action:
- Suppress sodium influx into the cells which inactivates the sodium channel, prevents neurons from firing the electrical impulses
- Suppress calcium influx- preventing the electrical current generated by those calcium ions
- Enhance action of GABA- amino acid that is inhibiting the neurotransmitters in the brain
Antiseizure Drugs Dosing
- Start low of antiseizure medication to get a therapeutic drug serum level
- Consistency- need to take these medications at the same time everyday
- Hard to control so they have to try multiple meds
CNS depressants because it depresses CNS function
Antiseizure Drugs
Effective in 75% of patients with seizures
Antiseizure Drugs
Does not cure seizures it manages the symptoms
Antiseizure Drugs
Taken for lifetime
Antiseizure Drugs
If not seizure activity for 3-5 years
Antiseizure Drugs
First group of anti seizure meds developed in 1938. prototype for antiseizure drugs
Hydantoins
Phenytoin (Dilantin)
Hydantoins
Phenytoin (Dilantin) Action
Inhibits sodium influx into the nerves cells, decreasing neuron from firing
Phenytoin (Dilantin) Dosing
Decrease dose with lower metabolism and liver disease. Increased dose for someone (children with high function liver) with a high metabolic rate.
Age-related
Based on serum drug levels.
Phenytoin (Dilantin) Therapeutic serum level
10 to 20 mcg/mL
Phenytoin (Dilantin) Contraindications
Pregnancy- Teratogenic drug
Phenytoin (Dilantin) Benefit
Slightly sedating and not addictive- benefit
Phenytoin (Dilantin) Highly protein bound=
more free drug= more risk of toxicity
Psychiatric effects- Depression or suicidal ideation
Phenytoin (Dilantin) Side effect
Nystagmus- involuntary eye movement, diplopia- double eye vision
Phenytoin (Dilantin) Side effect
Headache, dizziness, drowsiness(can occur at a therapeutic drug level)
Phenytoin (Dilantin) Side effect
N/V, constipation
Phenytoin (Dilantin) Side effect
Gingival hyperplasia- overgrowth of the gums that causes easily bleeding, normal side effect at a therapeutic level
Phenytoin (Dilantin) Side effect
Alopecia- hair loss
hirsutism- excessive body hair
Phenytoin (Dilantin) Side effect
Discolored urine- pink or red, brownish. educate clients, normal side effect
Phenytoin (Dilantin) Side effect
Hyperglycemia- happens in long-term use, inhibits release of insulin. Blood sugar checks
Phenytoin (Dilantin) Side effect
Blood dyscrasias0 thrombocytopenia(low platelet) leukopenia(low WBC counts)
Phenytoin (Dilantin) Side effect
Purple glove syndrome- swelling discoloration and decrease blood flow to the hands can require amputation
Phenytoin (Dilantin) Side effect
Stevens-Johnson syndrome- Rare, effects skin, mucus membranes, genitals and eyes. Flu-like symptoms and painful rash that causes blisters. Educate flulike or rash report immediately. Life threatening
Phenytoin (Dilantin) Side effect
Phenytoin Drug Interactions: Anticoagulants & ASA-
displace the anticoagulant (beats it), adds longer acting time of the anticoagulant
Phenytoin Drug Interactions: Barbiturates, rifampin, & alcohol-
increase metabolism, may need a higher dose
Phenytoin Drug Interactions: Sulfonamides and cimetidine-
can increase action of a hydantoin by inhibiting liver metabolism.
Phenytoin Drug Interactions: Antacids, calcium preparations, sucralfate, and antineoplastic-
Decrease the absorption
Phenytoin Drug Interactions: Antipsychotics and certain herbs-
decrease the seizure threshold, lowers drug therapeutic range, low enough so a seizure can be induces.
Highly protein bound drug it competes with other highly protein bound drugs for the receptor sites
Phenytoin
Phenytoin Assessment
Med history
Renal and hepatic lab function values
Urinary output
Kidney function is appropriate to excrete the drugs
Level of knowledge(compliance)
Ask about seizure history, is it chronic, is it related to a fever etc.
Phenytoin NSG Interventions
Monitor drug levels of antiseizure drugs to determine therapeutic range.
If increased number of seizures ask them about drug regimen and assess serum drug level.
Use seizure precautions.
Always address nutritional intake (electrolytes balanced, well balanced diet) because the amount of caloric intake.
Phenytoin Education
Compliant and consistent with medication regimen.
If female client is taking an oral contraceptive and taking an antiseizure drugs they need to change contraceptive.
Do not stop abruptly.
Once in steady state in the system they must be weaned off of it.
If the client is already diabetic, blood sugar levels will increase so they have to monitor BGL.
Avoid alcohol, decrease serum drug levels, effectiveness.
Any seizure meds, keep a log of their seizure medications for neurologist to show times and triggers.
Phenobarbital
Barbiturate
Phenobarbital Action
Enhances GABA activity, reduce the excitability of the CNS
Phenobarbital Used to tx
Tonic–clonic, partial, status epilepticus
Longer than 5 minutes seizures or so close together that the pt cannot recover in-between
status epilepticus
Phenobarbital Therapeutic serum range
15 to 40 mcg/mL
Wider therapeutic range, longer half life, allows for once daily dosing regimen.
More effective for someone because its a longer acting drug (once a day)
Phenobarbital Side effects
Sedation
tolerance-gradually withdrawal
decreased teratogenic risk- safest drugs for pregnancy and seizures
Phenobarbital Discontinuation
Should be gradual
What type of acting barbiturate is Phenobarbital
Long acting barbiturate
What type of acting are Sedative hypnotics
Short acting
Ethosuximide (Zarontin)
Succinimides
Ethosuximide (Zarontin) Action
Decreases calcium influx which prevents the electrical current generated by the calcium ions
Ethosuximide (Zarontin) Use to tx
Absence seizures (petit mal)- found in children
Ethosuximide (Zarontin) Therapeutic serum range-
40 to 100 mcg/mL
wide therapeutic range
GI upset- educate to take with food
Ethosuximide (Zarontin) Side effects/Adverse effects
Dizziness, drowsiness, headache, nightmares
Ethosuximide (Zarontin) Side effects/Adverse effects
Suicidal ideation
Ethosuximide (Zarontin) Side effects/Adverse effects
Gingival hyperplasia- measurable side effect and manageable, does not mean toxic level
Ethosuximide (Zarontin) Side effects/Adverse effects
Ataxia- lack of coordination
Ethosuximide (Zarontin) Side effects/Adverse effects
Blood dyscrasias
Ethosuximide (Zarontin) Side effects/Adverse effects
Renal and liver impairment
Ethosuximide (Zarontin) Side effects/Adverse effects
Systemic lupus erythematous -Once med is stopped= SLE will stop
Ethosuximide (Zarontin) Side effects/Adverse effects
Can have anti seizure effects
Benzodiazepines
Benzodiazepines that have anti seizure effects
Clonazepam (Klonopin)
Clorazepate dipotassium (Tranxene)
Diazepam (Valium)
Treats absence seizures
Tolerance may occur in 6 months of starting therapy, increase dosage after that time frame
Clonazepam (Klonopin)-
Treats partial seizures and anxiety, alcohol withdrawal
Clorazepate dipotassium (Tranxene)
Treats status epilepticus (drug of choice)
Must be administered IV for status epilepticus
Short-term effect- used with longer acting seizure medications
Used for anxiety and induce sedation
Diazepam (Valium)
Carbamazepine (Tegretol)- most commonly used drug in this drug class
Iminostilbenes
Carbamazepine (Tegretol) Tx
Tonic–clonic, partial seizures
Also used for psychiatric disorders (BPD), nerve pain (trigeminal neuralgia, diabetic neuropathy), and alcohol withdrawal
Carbamazepine (Tegretol) Therapeutic serum range
4 to 12 mcg/mL (narrow TR)
Monitor drug serum level closely
Carbamazepine (Tegretol) Side Effects
Dizziness, drowsiness, headache, blurred vision
GI distress
Ataxia
Weakness
Anemia
Agranulocytosis- low WBC count
Stevens-Johnson syndrome- rare
Grapefruit juice increases bioavailability of this drug, increasing risk for drug toxicity
Carbamazepine (Tegretol)
Valproic Acid (Depakote) Uses
tonic–clonic & absence
Valproic Acid (Depakote) Therapeutic serum range
50 to 100 mcg/mL
Wide therapeutic range
Valproic Acid (Depakote) Side effects/Adverse reactions
Dizziness
Drowsiness
Insomnia
Diplopia
Weakness
GI distress
Suicidal ideation
Thrombocytopenia
Hepatotoxicity- major adverse reaction, monitor liver labs closely
Not safe for children under the age of 2
Valproic Acid (Depakote)
Antiseizure Drugs and Pregnancy: Seizure episodes can increase and
Teratogenesis
Antiseizure Drugs and Pregnancy: ____ are linked to cardiac defects, cleft lip, palate defects
Phenytoin & Carbamazepine
Antiseizure Drugs and Pregnancy: Occur in small percentage of infants, 4-8% chance of congenital defects if they take it during pregnancy
Valproic acid
Antiseizure Drugs and Pregnancy: least amount of effects on fetus
Phenobarbital
Antiseizure Drugs and Pregnancy: Inhibits vitamin k- seizure medications, baby has an increased risk of clotting.
Should take a vitamin K supplement a week-10 days before delivery and baby receive vitamin k injection
Vitamin K
Antiseizure Drugs and Pregnancy: Risk for neural tube defects.
Increase Folic acid
Seizures in pregnant women can increase by __ because of increased metabolism rate during pregnancy
Hypoxia can occur- mother and fetus at risk (placental blood flow)
25%
More than one drug to have a decrease seizure activity in pregnancy bc of metabolic rate
increases
Antiseizure Drugs and Febrile Seizures: Febrile Seizures-
increase in body temp, most commonly seen of 3 month-5yrs.
About 2.5% of children who have febrile seizures develop epilepsy.
Antiseizure Drugs and Febrile Seizures: Seizures associated with
fever
Antiseizure Drugs and Febrile Seizures: Development of epilepsy is
uncommon
Antiseizure Drugs and Febrile Seizures: Prophylactic treatment for high-risk patients- if using preventative meds
Phenobarbital
Diazepam
Preventative seizures meds are not indicative
Only at a high risk for developing seizures
Antiseizure Drugs and Febrile Seizures
Antiseizure Drugs and Status Epilepticus: Medical
emergency
Antiseizure Drugs and Status Epilepticus: Needs
Tx
Antiseizure Drugs and Status Epilepticus: Diazepam IV (drug of choice, benzo) or Lorazepam IV followed by
Followed by IV Phenytoin or Phenobarbital
Antiseizure Drugs and Status Epilepticus: Continued Seizures worry about (sedation, depression, respiratory)
Used for surgical procedures, depression of CNS
Midazolam-versed
Propofol
If not treated it can result in death
Status epilepticus
What is the highest priority nursing diagnosis for a patient taking phenytoin (sedative effect, dizziness, ataxia)?
Risk for falls
Before administering a daily dose of phenytoin, it is most important for the nurse to
check phenytoin levels.
10-20 therapeutic range, narrow
When assessing a patient taking hydantoin therapy for seizure disorder, which indicates an adverse reaction to this therapy?
Thrombocytopenia (blood dyscrasias)
A patient is experiencing status epilepticus. The nurse anticipates immediate administration of which drug?
Diazepam
Chronic progressive neurologic disorder
Parkinson’s Disease Pathophysiology
Degeneration of dopaminergic neurons leading to a lack of dopamine
Parkinson’s Disease Pathophysiology
Imbalance of neurotransmitters not enough dopamine compared to acetylcholine
Parkinson’s Disease Pathophysiology
No cure, effects the extrapyramidal system, controls out posture balance and locomotion
Parkinson’s Disease
Results from loss of neurons that are producing dopamine, part of the brain called the substantia nigra
Parkinson’s Disease
Dopamine controls excitatory response from the acetylcholine
Parkinson’s Disease
Too much acetylcholine stimulates too much GABA which causes the symptoms
Parkinson’s Disease
Effects more men than women
Parkinson’s Disease
Can occur with Carbon monoxide and manganese poisoning
Parkinson’s Disease
Pseudoparkinsonism
Result of getting Parkinson like symptoms that are caused by other drugs
Frequently occurs as an adverse reaction to various drugs
Pseudoparkinsonism causing meds
Chlorpromazine
Haloperidol
Lithium
Metoclopramide
Methyldopa
Reserpine
Parkinson’s Disease Characteristics
Involuntary tremors of limbs (extremities)
Rigidity of muscles
Bradykinesia – slow movements
Postural changes- head and chest pushed forward and shuffling gait
Lack of facial expression
Pill-rolling motion of hands
Extrapyramidal system- posture effected, rebalance themselves by compensating
Nonpharmacologic measures for Parkinson’s Disease:
Exercise, Nutrition, and Group support
Exercise-
Improve mobility and flexibility, used to help slow the decline in the quality of life
Nutrition-
fiber and fluids diet to prevent weight loss and constipation.
Constantly tremoring, caloric intake and output equal imbalanced
Group support-
family members/caregivers because of chronic progressive disease, coping
Parkinson’s Disease Treatment
Anticholinergics, Dopamine replacements, Dopamine agonists, MAO-B inhibitors, COMT inhibitors,
Anticholinergics-
blocking receptors of acetylcholine bc too much. Allows dopamine balance to be restored
Dopamine replacements-
replacing endogenous dopamine and binding with dopamine receptors
Dopamine agonists-
dopamine replacement, stimulating dopamine receptor
MAO-B inhibitors-
inhibits monoamine oxidase b enzyme, involved in the metabolism of dopamine, decrease dopamine metabolism to increase dopamine receptors. Inhibiting the break down
COMT inhibitors- catechol o methyltransferase
Enzyme that deactivates dopamine, inhibiting that from occurring. Allows more dopamine to be available. Antagonist agonist
Replace dopamine and reduce symptoms
Parkinson’s Disease Treatment
Antiparkinson Drugs
Anticholinergics
Anticholinergics Example
Benztropine & Trihexyphenidyl
Benztropine & Trihexyphenidyl Action
Reduces rigidity and some of the tremors
Minimal effect on bradykinesia
Benztropine & Trihexyphenidyl Side effects
Blurred vision
Mydriasis
Ocular hypertension (Glaucoma contra)
Weakness
Dry mouth (regulate drooling),
Constipation
Anhidrosis(decreased sweating)
Urinary retention
Activating the nicotinic receptors and muscuenic receptors through out the body
Anticholinergics
Helps reduce the muscle tone and tremors, does not have good effect on the bradykinesia
Anticholinergics
Also used to treat pseudo Parkinson, drug induced Parkinson’s
Anticholinergics
Antiparkinson: Anticholinergic Agent Assessment
Full medical history looking for glaucoma and parkinsonism
Worried if they already have GI constipation, dysfunction, urinary retention, myasthenia gravis
Drug history, Antihistamine can increase the effect of an anticholinergic (trihexyphenidyl)
Baseline vital signs
See the stage of Parkinson disease progression, current s/sx.
Know ability for drug regimen.
Baseline urinary output for urinary retention
Antiparkinson: Anticholinergic Agent NSG Interventions
vital signs
urinary retention
bowel movements
watch for increase pulse rate
hypervolemia
constipation,
monitor effects on drugs and how effective they are on symptoms.
Antiparkinson: Anticholinergic Agent Education
Safety measures- safety bar in shower, elevated toilet seat, shower chair, removing throw rugs. Adding extra lighting, eliminating danger.
Dopaminergics
Antiparkinson Drugs
Dopaminergics Example
Carbidopa-levodopa
Carbidopa
Prolongs the effect of levodopa
Carbidopa-levodopa action
Converts to dopamine and increases mobility
Carbidopa-levodopa Side effects
Fatigue, insomnia, dry mouth, blurred vision
Orthostatic hypotension- seen beginning the TX, decreases overtime, palpitations, dysrhythmias, Agranulocytosis
Constipation, N/V, urinary retention, urine discoloration
Dyskinesia- involuntary movements, psychosis, severe depression- report immediately
Dopamine itself cannot cross BBB but
levodopa can by converting into dopamine
___ inhibits the enzyme decarboxylase that’s breaking down levodopa in the body
Carbidopa
levodopa turns into dopamine = increasing levels of
dopamine
When levodopa is used alone, only __ reaches the brain because __ converts to dopamine while in the peripheral nervous system
1%
99%
By combining carbidopa with levodopa, carbidopa can inhibit the enzyme __ in the periphery, thereby allowing more levodopa to reach the brain.
decarboxylase
Levodopa taken alone-
10mg of 500mg reaches the brain, 5%
When carbidopa given with levodopa a smaller dose-
10mg of 100mg gets to the brain = 10% effectiveness, decreases side effects
Dopaminergics (carbidopa-Levodopa) Asessment
vital sign baseline, drug history, medical history, s/sx
Dopaminergics (carbidopa-Levodopa) Nursing Interventions-
orthostatic hypotension
increase water and salt intake
take carbidopa and levodopa with low protein foods.
High protein food effects/blocks how the drug goes to the CNS
Dopaminergics (carbidopa-Levodopa) Education
Family support and educating support system
drug regimen is taken properly
Short half life- 1-2 hrs.
Need to take frequently through out the day, cannot abruptly stop med can cause rebound symptoms.
Can cause urine discoloration-will darken with exposure to the air- harmless.
Perspiration(Sweat) not clear, educate.
Can be taken with food (low protein), can cause GI upset.
If given with food, absorption can be delated.
Therapeutic response takes several months, educate to not stop taking med.
Bromocriptine(dopaminergic)
Dopamine Agonists
Bromocriptine(dopaminergic) Action
Acts directly on dopamine receptors in CNS, cardiovascular system, & GI tract
Used when pts do not tolerate carbidopa-levodopa
Dopamine agonist direct acting
Can be taken alone or with carbidopa-levodopa, when given together the dosages of each can be decreased. Can reduce side effects and drug tolerance
Bromocriptine(dopaminergic)
Selegiline
Monoamine Oxidase B Inhibitors
Selegiline Action
Inhibit MAO-B enzyme that interferes with dopamine
Selegiline Interaction
Food high in tyramine can cause hypertensive crisis
CNS toxicity with tricyclic antidepressants or SSRIs
Breaks down dopamine enzyme, Inhibiting from occurring
Selegiline