Drugs Affecting the Nervous System Flashcards
Chemical messengers of NS
Exert actions through receptors in postsynaptic membrane
Interaction of transmitter/receptor results in specific physiologic response
Rapid removal of transmitter needed to maintain precise control of neural transmission
Receptors named for type of neurotransmitter with which they interact
Basic concepts neurophysiology: communication neurotransmitters
Neurotransmitters, neuromodulators, neurotrophic or nerve growth factors
Chemical messengers of NS
Missing Ach in Alzheimers
Undersupply dopamine = Parkinson’s
GABA - major inhibitory NT; treatment of seizures
Review neurotransmitters
Simultaneous disruption of electrical activity/onset originate in bilateral hemispheres
Tonic–clonic seizure is most common major motor seizure: the 2 phases of seizure activity
Generalized Seizures
Begin in a specific area of cerebral hemisphere
With impaired consciousness (impaired awareness) or without impairment of consciousness (aware)
Focal Seizures
Chronic disorder of recurrent seizures
Epilepsy
When has Multiple seizures occur back to back with no recovery between them- hypotension, hypoxia, brain damage, and death (more sig implications result); med Emergency to get stop so no cardiac/resp probs or brain damage – diazepam (benzo - slow seizure activity) - not fine line on when given; vary between pats
Status epilepticus
alter movement of sodium, potassium, calcium, and magnesium ions; changes in movement of ions result in more stabilized and less excitable cell membranes; nerve membranes less excitable to decrease seizures; some later movement electrolytes, some enhance action GABA; whole goal: neurons less excitable
MoA: - Gen: anti-seizure (AS) meds
GI upset (n/v)
CNS depression (drowsiness, lethargy, fatigue) - less excitable; do more than want to see this and experience this; lot drugs cause CNS depression so aware and monitor for this
Confusion
Ataxia - rigid and clumsy like movements - gait; inability do fluid muscle movement esp with gait; diff with speech
Adverse Effects - Gen: anti-seizure (AS) meds
Hepatotoxicity - LFTs yearly; meds for long period time
Toxicity: - Gen: anti-seizure (AS) meds
CNS depressants (more than 1 worse), alcohol, many others (highly protein bound - compete for protein binding sites and higher levels of drug free to exert effect and higher risk for toxicty)
Drug-drug: - Gen: anti-seizure (AS) meds
Risk of birth defects with many anti-seizure meds; weigh benefit vs. risk - not have seizures all time - not have O2 deprivation
Risk severe seizure activity with abrupt withdrawal of medication - balance NT and through out balance and cause probs with pat - r/f major seizure
Monitor drug levels for toxicity - blood monitoring imp
Black box waring: Suicidal ideations - less NT activity - r/f depression and SI
Cautions: AS meds
Advise contraception, notify PCP if pregnancy occurs or want to be pregnant
Medications pregnancy cat C/D/X
Risk of birth defects with many anti-seizure meds; weigh benefit vs. risk - not have seizures all time - not have O2 deprivation
potentiates effects of GABA; drug of choice in acute care when having a seizure
MoA: - Benzodiazepines: Prototype: diazepam (Valium)
status epilepticus
Use: - Benzodiazepines: Prototype: diazepam (Valium)
IVP (2 mg/min) - not swallow since acute seizure; onset: 1-5 min; peak 30 min; duration: 60 min
Route: - Benzodiazepines: Prototype: diazepam (Valium)
respiratory depression, bradycardia, hypotension
AE: - Benzodiazepines: Prototype: diazepam (Valium)
Monitor cessation of seizure activity - if not might give second dose of med - wait 5 min until give 2nd dose, once activity stops monitor VS for certain period of time and not having any AE
Nursing: - Benzodiazepines: Prototype: diazepam (Valium)
Stabilize nerve membranes throughout CNS-less excitability
MoA: - Hydantoins: Prototype: phenytoin (Dilantin)
see general; gingival hyperplasia (overgrowth of gum tissue)
AE: - Hydantoins: Prototype: phenytoin (Dilantin)
Many - highly protein bound, hepatic enzyme inducer; warfarin - increased risk for bleeding
Drug-Drug: - Hydantoins: Prototype: phenytoin (Dilantin)
therapeutic blood level: monitor levels; see next slide for IV administration; teach and maintain good oral hygiene - more bacteria in mouth - increased risk for dental probs
Nursing: - Hydantoins: Prototype: phenytoin (Dilantin)
Intravenous push: use large vein and large catheter; do not exceed 50 mg/min
Intravenous infusion: only dilute in NS; use with particular kind of filter - so not percipitate
Follow with normal saline flush to decrease risk of local venous irritation
Monitor IV site for inflammation and extravasation
More sig AE: Monitor cardiac rhythm (bradycardia) and affect blood pressure; on cardiac monitor and monitor BP frequently during IV infusion
Phenytoin IV admin
Enhances action of GABA neurotransmitter to slow down activity in brain and less excitability
MoA: - Barbiturates: Prototype: phenobarbital (Luminal)
See general; general AE resolve over time
AE: - Barbiturates: Prototype: phenobarbital (Luminal)
respiratory depression, coma (particularly sig and higher risk with IV route, be cautious)
Toxic: - Barbiturates: Prototype: phenobarbital (Luminal)
therapeutic blood level: monitor levels; admin once daily dosing at HS due to sedating effects - more sedating than other drugs so take HS if only taking qday
Nursing: - Barbiturates: Prototype: phenobarbital (Luminal)
Increases levels of GABA in brain
MoA: - Miscellaneous: Prototype: valproic acid
See general; weight gain; increased bleeding time; toxic: pancreatitis
AE: - Miscellaneous: Prototype: valproic acid
Many - Highly protein bound; warfarin - increased bleeding: monitor bleeding times if taking with this, labs likely drawn frequently
Drug-Drug: - Miscellaneous: Prototype: valproic acid
Do not crush or chew extended release (ER) - available immediate and ER forms
Nursing: - Miscellaneous: Prototype: valproic acid
Focused neuro: LOC and orientation; assessments related to AE
Consider Pregnancy status, drug-drug interactions (CNS depressants)
Labs: drug levels (if appropriate), kidney/liver if toxicity suspected
Assessment
Risk for injury
Nursing Diagnosis
The client will have an absence of seizure activity
The client will understand drug therapy, adverse effects, safety measures
Expected Outcomes
Reduce risk for falls
Seizure precautions: padding around bed rails, suction available, O2 ready and available; keep them as safe as possible
Counsel women of childbearing age
Lab monitoring for therapeutic levels (if appropriate); below: not problematic if not having seizures; get to make sure not becoming toxic; care if above: at risk for toxicity
Educate:
Nursing care plan: interventions
Seizure disorder will need med therapy for lifetime
Discontinue drug slowly; abrupt withdrawal may precipitate seizures; take as directed; call if having certain AE
Caution with driving until effects of medication known - CNS depression and impact driving and seizure
Lab monitoring - AS drugs q3months once stable; start more often
Educate:
Therapeutic response
Monitor for Adverse effects
Teaching
Nursing care plan: eval
Absence of seizure activity
Therapeutic response
CNS depression, confusion, ataxia
GI effects
Signs of toxicity
Med specific
Monitor for Adverse effects
More sensitive to sedating effects, monitor closely
Children 2 months – 6 years absorb and metabolize quickly; may require larger dose per kilogram to maintain therapeutic levels
Child - Lifespan considerations: anti-seizure meds
Medic Alert identification
Consider lifestyle changes (work [impacts financial status], transportation, etc.)
Adult - Lifespan considerations: anti-seizure meds
More susceptible to adverse effects, toxicity
Dose adjustments for reduced liver/kidney function
Older adult - Lifespan considerations: anti-seizure meds
PD: dopamine; CM: tremors, shuffling gait, drooling, mask like facial expression, anticholinergic effects because AcH levels higher than dopamine
AD: neuronal death because of amyloid plaque- lack AcH; memory impairment, loss motor func and speech
Recall the pathophysiology of Parkinson’s disease and Alzheimer’s disease with special attention to levels of neurotransmitters. Recall common clinical manifestations of Parkinson’s disease and Alzheimer’s disease
No cure for Parkinson’s disease or Alzheimer’s disease
Medications used for treatment take several months to take effect
Medications help alleviate manifestations of Parkinson’s disease
Medications slow progression of disease in Alzheimer’s dementia – earlier more benefit
Special considerations
Improvement in several months
Medications help alleviate manifestations of Parkinson’s disease
Improvement in 4-6 weeks
Medications slow progression of disease in Alzheimer’s dementia – earlier more benefit
Restores dopamine concentration in brain (combo); Levodopa - active part, broken down in periphery, not liver like norm, if given on own body break down quickly and faster than get to BBB to restore dopamine levels; Carbidopa - given to prevent breakdown Levodopa before body can use it, lower doses Levodopa can be given - major AE higher doses: huge GI effects (n/v)
MoA: - Dopaminergic agent: Prototype: Levodopa/Carbidopa (Sinemet)
Parkinson’s disease - main stage disease treatment
Indication: - Dopaminergic agent: Prototype: Levodopa/Carbidopa (Sinemet)
antihypertensives (inc. hypotension); CNS dep (increase sedation)
Drug-drug: - Dopaminergic agent: Prototype: Levodopa/Carbidopa (Sinemet)
CV disease, asthma, urinary obstruction, peptic ulcer disease
Caution: - Dopaminergic agent: Prototype: Levodopa/Carbidopa (Sinemet)
(low BP and anticholinergic effects): orthostatic hypotension, dry mouth, constipation, urinary retention, confusion, agitation, insomnia
AE - Dopaminergic agent: Prototype: Levodopa/Carbidopa (Sinemet)
maintain compliance; Abrupt cessation may cause parkinsonism crisis - acute exacerbation: severe presentation of Parkinson’s disease; take as prescribed and do not double doses - can build up tolerance over time - start lowest dose so careful in how increase med - once increase med lower doses never effective again
Nursing: - Dopaminergic agent: Prototype: Levodopa/Carbidopa (Sinemet)
Enhances the effects of acetylcholine in neurons in cerebral cortex that have not been damaged
MOA: - Alzheimer’s Disease: Cholinesterase Inhibitor (cholinergic agonist): Prototype: donepezil (Aricept)
Alzheimer’s disease - first line treatment and delay progression
Indication: - Alzheimer’s Disease: Cholinesterase Inhibitor (cholinergic agonist): Prototype: donepezil (Aricept)
n/v/d, insomnia or drowsiness (more common), bradycardia/AV block
AE: - Alzheimer’s Disease: Cholinesterase Inhibitor (cholinergic agonist): Prototype: donepezil (Aricept)
Assess BP/HR; monitor mental status; give at bedtime unless insomnia occurs; Teach - not to increase or decrease dose abruptly; Risk cholinergic crisis (too much AcH and cause it; risk present but rarely seen but NT missing); earlier start the better; once increase no turning back
Nursing: - Alzheimer’s Disease: Cholinesterase Inhibitor (cholinergic agonist): Prototype: donepezil (Aricept)
are drugs that reduce or eliminate pain by depressing nerve function in the central and/or peripheral nervous system
Anesthetics
involves complete loss of consciousness and loss of body reflexes so adequately perform surgery, including respiratory muscles (requires ventilatory support to avoid brain damage); endotracheal tube
General anesthesia
allows patient to relax and tolerate procedure but maintains respiratory function and response to stimuli; colonoscopy/EGD; breathing on own
Registered nurses may be trained to administer moderate sedation
Must have advanced cardiac life support (ACLS) training
Moderate sedation (conscious sedation, procedural sedation)
Ensure life support equipment readily available prior to start of procedure
Ensure patent IV for administering drugs
Gather supplies to administer drugs intravenous push (IVP): Syringes, alcohol prep, flushes, drug vials
Monitor patient’s level of consciousness and pain during procedure
Monitor patient’s vital signs during procedure
Alert provider of concerning changes in patient status
Monitor LOC and VS following procedure
Standard protocols on how often monitor after procedure - VS and LOC - waking up after
Nurse role: moderate sedation
Trained intensive care registered nurses
Assist with intubation of patient
Manage sedation to keep patient comfortable and tolerant of endotracheal tube
Taper drugs prior to extubating (removing endotracheal tube)
Nurse role: medically-induced coma
Gather supplies to administer drugs IVP (i.e.; midazolam, rocuronium)
Administer drugs as directed by anesthesia provider
Sequence: benzodiazepine/some kind sedative - sedate and make them more comfy, then paralytic - paralyze muscles so stop breathing so can insert ET tube in right spot and once there attach ambu back attached to ventilator
Assist with intubation of patient
Cont give Intravenous infusions of midazolam and fentanyl - comfy and tolerate presence of ventilator
Manage sedation to keep patient comfortable and tolerant of endotracheal tube
Moderate sedation for diagnostic procedures, induction of anesthesia (surgery), sedation of intubated patients, decrease anxiety prior to procedure
Indications: - Benzodiazepines (Anesthetic): Prototype: midazolam (Versed)
(IVP in acute care to help with sedation): 1-5min/<30 min/2-6 hours
Onset/peak/duration - Benzodiazepines (Anesthetic): Prototype: midazolam (Versed)
CNS depressants, opioids
Drug-drug: - Benzodiazepines (Anesthetic): Prototype: midazolam (Versed)
respiratory depression, CNS depression, disorientation, amnesia, restlessness, bradycardia, hypotension
AE: - Benzodiazepines (Anesthetic): Prototype: midazolam (Versed)
Assume patient will remember things said/done during sedation/anesthesia
Nursing: - Benzodiazepines (Anesthetic): Prototype: midazolam (Versed)
Bind to ACh receptors at neuromuscular junction, blocking action of ACh; induces paralysis of skeletal muscle and beneficial for sedation (peripheral to central); paralytic drug
MoA: - Neuromuscular Blocking Drugs: Prototype: Rocuronium
Endotracheal intubation; surgery
Indication: - Neuromuscular Blocking Drugs: Prototype: Rocuronium
(IV): 1-2 min/4 min/30 min - quickly relaxed so hooked up quickly to ventilator imp
Onset/peak/duration - Neuromuscular Blocking Drugs: Prototype: Rocuronium
muscle damage, hyperkalemia, cardiovascular collapse (more likely with larger dose, prolonged administration when at highest risk)
AE: - Neuromuscular Blocking Drugs: Prototype: Rocuronium
Administer prescribed sedation prior to neuromuscular blocking agent/paralytic drug
Nursing: - Neuromuscular Blocking Drugs: Prototype: Rocuronium