Term
| netrotransmitters - chemical signaling between cells |
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Definition
- each neuron is a distinct anatomical unit - no structural continuity exists between most neurons
- communication between nerve cells & between nerve cells & effector organs - occurs through the release of specific chemical signals (neurotransmitters) from the nerve terminals
- release of neurotransmitters depends on processes that are triggered by Ca uptake & regulated by phosphorylation of synapitc proteins
- neurotransmitters rapidly diffuse across the synaptic cleft or synapse btwn nerve endings & combine w/ specific receptors on the postsynaptic (target) cell
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Term
| types of neurotransmitters |
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Definition
- over 50 chemical signal molecules have been identified in the nervous system
- six signal compounds are most commonly involved in the actions of therapeutic drugs
- NE and E
- ACh
- dopamine
- serotonin (5-HT)
- glutamate
- gamma-amminobutyric acid (GABA)
- each of these binds to a specific family of receptors
- cholinergic (ACh-transmitter) & adrenergic (NE & E-transmitters) are the primary signals in the autonomic nervous system
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Term
neurotransmitters in the CNS: basic functioning of neurons in the CNS is similar to that of the autonomic NS similarities: |
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Definition
- in both systems, transmission of info involve the release of neurotransmitters that diffuse across the synaptic space to bind to specific receptors on the postsynaptic neuron
- in both systems, recognition of the neurotransmitter by the membrane receptor of the postsynaptic neuron triggers intracellular changes
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Term
neurotransmitters in the CNS differences from those in the autonomic NS |
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Definition
- circuitry of the CNS-much more complex than the autonomic nervous system
- number of synapses in the CNS - much greater
- CNS communicates through the use of >10 (and perhaps as many as 50) different neurotransmitters; in contrast, the autonomic NS uses only 2 primary neutrotransmitters, ACh & NE
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Term
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Definition
- chronic brain disorder characterized by recurrent seizures, ranging from brief unconsciousness to violent, life threatening convulsions
- seizure: an abnormal discharge of electrical impulses within the brain, resulting in changes in awareness, sensory alterations & involuntary muscle movements; in most pts, intelligence is not affected
- 3 or more seizures = epilepsy
- epilepsy affects about 2.3 million Americans (1% population), with circa 181,000 new cases/year
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Term
etiology: primary epilepsy |
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Definition
- no specific anatomic cause is evident & the pt has no other neurologic abnormality
- called idiopathic or primary epilepsy ("essential")
- may be prodcued by an inherited abnormality in the CNS
- about 70% of all seizures
- pts are treated w/ antiepileptic drugs, often for life
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Term
etiology: secondary epilepsy |
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Definition
- can be a sympton of an underlying condition or illness & may resolve spontaneously when the problem is treated
- etiology of isolated seizures:
- electrolyte imbalances (esp low sodium)
- renal & liver failure
- hypertensive encephalopathy (major issue)
- hypoglycemia
- acute head trauma
- ingestion of toxins (e.g. mercury, lead, CO) - esp heavy metals
- CNS infection (meningitis)
- fever (kids usually grow out of this)
- antiepileptic drugs are given untilthe primary cause can be corrected
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Term
CLASSIFICATION OF EPILEPSY Partial (one hemisphere of brain) |
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Definition
- Simple
- no loss of consciousness
- diverse symptoms
- limited motor involvement
- sensory or psychic symptoms
- responsive during attack
- usually less than 1 min
- Complex: psychomotor-temporal lobe seizures
- usually preceeded by aura
- loss of impaired consciousness
- symptoms may be similar to "simple"
- coordinated involuntary movements (drooling, wandering, laughing)
- usually 1-2min in duration
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Term
CLASSIFICATION OF EPILEPSY Generalized (both hemispheres of brain) *partial may spread to this |
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Definition
- Absence seizures: non-convulsive; "petit mal"
- abrupt loss of consciousness
- no loss of postural control
- fixed stare, blinking, mild jerking, mouth movements or grimacing
- usually 15-30sec duration
- abrupt end of seizure
- fully alert (consciousness almost immed. returns)
- Tonic-Clonic seizures: convulsive; "grand mal"
- arms & legs flex rigidly
- audible cry heard
- arms & legs extend rigidly
- whole body jerking and spasms
- loss of consciousness
- tonic-clonic phase usually 1 min
- disorientation & slow recovery (post-ictal phase= 15-30min)
- no recall of event
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Term
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Definition
- continuous seizure state, lasting for 30min or more without the pt regaining consciousness & usually accompanied by respiratory distress - medical emergency
- can occur during all types of seizures
- emergency tx usually consists of diazepam, pheytoin, or phenobarbital
- if seizures are secondary to hypoglycemia - IV dextrose 50%
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Term
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Definition
- about 40-80% of pts w/ epilepsy respond to drug therapy, have good quality of life and a normal life span
- most other cases can be cured by neurosurgery that involves destroying or ablating the epileptic focus within the brain or sectioning the corpus callosum between the hemispheres to decrease the transmission of abnormal impulses
- noncompliance with the drug regime-major reason of seizure control failure
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Term
| nursing considerations with epilepsy |
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Definition
- teach pt to avoid factors that can precipitate a seizure, including stress, excessive heat, ETOH, sleep deprivation & certain drugs
- pregnancy lowers seizure threshold
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Term
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Definition
antiepileptic (anticonvulsant) drugs three basic targets for antiepileptic drugs: - neuronal membrane stabilization (Na or Ca channels)
- potentiate GABA (inhibitory neurotransmitter)
- decrease actions of glutamate and/or aspartate
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Term
antiepileptic drugs: Barbiturates |
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Definition
phenobarbital (Luminal) - only limitation to using these in seizure management is their sedative effect which increases as dosage increases
- controls seizures by inhibiting the spread of focal firing of abnormal neurons in the CNS, which suppresses the seizure
- its mechanism of action is not fully understood; may involve potentiation of the inhibitory effects of GABA-mediated neurons; it also decreases Na/K conduction at high levels
- doses required for antiepileptic action are lower than those that cause pronounced CNS depression
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Term
| pharmacotherapeutics of barbiturates |
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Definition
- all types of seizures, except absence seizures (may actually worsen these seizures)
- more effective in simple partial seizures than in complex partial seizures
- regarded as the first choice in treating recurrent seizures in children, including febrile seizures
- effective in status epilepticus
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Term
| pharmacokinetics of barbiturates |
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Definition
- well absorbed PO
- freely penetrates the brain
- about 75% is metabolized by liver & 25% is excreted unchanged by kidney
- long half-life (60-120hrs)
- potent inducer of the P-450 system & when given chronically, it enhances the metabolism of other agents
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Term
| contraindications of barbiturates |
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Definition
- hypersensitivity
- severe respiratory disorders
- h/o ETOH & drug abuse
- severe liver & kidney impairment
- caution in elderly: increased sedation; measures to ensure safety especially important
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Term
| adverse effects of barbiturates |
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Definition
- sedation, ataxia, nystagmus, vertigo, hangover effect & drowsiness - most common
- GI problems, Stevens-Johnson syndrome - less common
- paradoxical rxn (CNS excitation) - restlessness, anxiety, irritability,tachycardia, insomnia
- acute toxic effect can be potentially lethal; requires serum blood level monitoring; TI: 15-40
- barbiturates have an addictive nature w/ long term use
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Term
| drug-food interactions with barbiturates |
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Definition
- ETOH & CNS depressants: severe CNS depression
- anticoagulants: their effects decreased
- estrogen-containing oral contraceptives: reduced reliability
- many other drug interactions b/c potent inducer of P-450 system
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Term
antiepileptic drugs: Hydantoins |
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Definition
phenytoin (Dilantin) - most commonly prescribed antiepileptic agent
- known as broad-spectrum; effective in basically all forms of epilepsy except absence seizures
- often drug of choice in adults & older kids
- at therapeutic doses, does not cause general CNS depression
- believed to stabilize membranes (hyperpolarization) & prevent spread of seizures from a hyper-reactive focus
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Term
| pharmacotherapeutics of hydantoins |
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Definition
- effective in treating tonic-clonic seizures & partial seizures but not absence seizures
- also used in tx of status epilepticus after administration of diazepam
- used in prevention & tx of seizures in pts undergoing neurosurgery (prophylactic)
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Term
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Definition
- oral absorption is slow
- half-life varies from 12-36hrs, with an average of 24hrs
- pt-pt variation in absorption/metabolism
- steady-state blood levels may be reached in 5-7 days at low serum levels & 4-6 weeks at higher blood levels
- therapeutic plasma level range: 10-20
- 90% of the drug is protein bound, therefore in hypoalbuminemic states, there will be an increase in free drug & serum levels; protein bidning competition with valproic acid, salicylates, sulfa drugs
- metabolize in the liver & excreted in the bile & urine as inactive metabolite
- bioavailabilities of phenytoin preparations differ significantly (caps vs. tabs) & from one manufacturer to another - preparations should not be switched
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Term
| contraindications of hydantoins |
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Definition
- contraindicated in hypersensitivity reactions, bradycardia & severe kidney & liver disease
- caution in elderly
- caution in pregnancy pts: congenital defects (if status epilepticus, no other choice)
- multiple drug/food interactions, check when administering
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Term
| adverse effects of hydantoins |
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Definition
- common: ataxia, nystagmus & alterations in extraoccular movements, diplopia, slurred speech, stuttering, trembling of hands - occur when serum levels are above 20
- GI: constipation, n/v/d
- cosmetic (may affect compliance):
- gingival hyperplasia, hirsutism, nystagmus, rash, coarsening of facial features
- serious: arrhythmias, seizures, leukopenia, thrombocytopenia, abnormalities in vit D metabolism, teratogenic (produces fetal hydantoin syndrome, which is characterized by prenatal growth/mental deficiences; also incrase incidence of congenital malformations such as cleft palate)
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Term
| nursing considerations for hydantoin |
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Definition
- elderly tend to metabolize hydantoins slowly, increasing potential for toxic serum levels
- tolerated well when given IM (if IV, must be hung within 15 min and infused at quick rate)
- avoid ETOH and other CNS depressants
- avoid abrupt discontinuation
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Term
antiepileptic agents: carbamazepine (Tegretol) |
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Definition
- has become a mainstay in tx of many forms of epilepsy (safer than the others)
- therapeutic levels range from 4-12
- reduces the propagation of abnormal impulses in the brain by blocking Na channels, thereby inhibiting generation of repetitive action potentials in the epileptic focus
- highly effective for all partial seizures (simple & complex) - often drug of first choice
- highly effective for tonic-clonic seizures
- used to treat trigeminal neuralgia & chronic pain syndromes
- used in main-depressive pts to ameliorate symptoms
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Term
| pharmacokinetics of carbamazepine: |
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Definition
- absorbed slowly following PO admin
- enters brain rapidly b/c of high lipid solubility
- initial half-life: 40hrs; continued use = 15hrs
- induces its own metabolism, which is known as time-dependent kinetics; shortly after therapy begins, metabolism of this drug may increase significantly & half-life decreases w/ chronic use, causing fluctuation in serum levels over time
- enhanced hepatic P-450 system activity also incrases the metabolism of other antiepileptic drugs
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Term
| contraindications and drug interactions of carbamazepine |
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Definition
- h/o bone marrow suppression
- hypersensitiity to the tricyclic antidepressents
- taking monoamine oxidase (MAO) inhibitors
- hepatic metabolism of carbamazepine is inhibited by several drugs; toxic symptoms may arise if the dose is not adjusted
- OC: increased metabolism of estrogen - a decreased effectiveness of OC (all inducers of P-450 do this)
- anticoagulants: decreased effectiveness (all inducers do this)
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Term
| adverse effects of carbamazepine |
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Definition
- sedation (common, but usually disappear over time)
- drowsiness, vertigo, ataxia, blurred vision
- irritating to the stomach: nausea, emesis
- aplastic anemia, agranulocytosis, thrombocytopenia - possibility
- potential for inducing serious liver toxicity
- CBC initially, then weekly x 4mo, then q3mo
- liver enzymes initially @ 2wks, then q3-6mo
- in most pts, adverse effects usually disappear within 2-3wks after initiation of therapy
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Term
antiepileptic drugs: valproic acid (Depakene, Depakote) |
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Definition
- broadest spectrum form of antiepileptics (all but febrile)
- second drug of choice for absence seizures (drug of choice for myoclonic)
- therapeutic levels range from 50-100
- inhibits enzyme breakdown of GABA to a simpler form, thereby selectively increasing the coc of GABA in the synapses, which reduces seizures activity
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Term
| pharmacotherapeutics of valproic acid: |
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Definition
- similar to carbamazepine + absence seizures
- most effective agent available for tx of myoclonic seizures
- used for igraine prophylaxis
- used in tx of refractory bipolar disorders
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Term
| pharmacokinetics of valproic acid |
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Definition
- effective PO & rapidly absorbed; bioavailability after PO dosing is > 80%
- peak levels occur within 2 hrs; food may delay absorption
- 90% is boind to plasma proteins
- only 3% is excreted unchanged; the rest is converted to active metabolites by the liver
- metabolized by the P-450 system but does not induce the enzymes of the system
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Term
| contraindications of valproic acid |
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Definition
- pts w/ hepatic disease b/c of its hepatotoxic effects
- pts w/ bleeding disorders secondary to decreased clotting
- caution in pregnancy
- caution in clients taking warfarin b/c of potential displacement
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Term
| drug/food interactions with valprioc acid |
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Definition
- carbamazepine, phenobarbital: inhibited metabolism and increased levels of these drugs (use w/ phenobarb. may cause excessive sedation leading to coma)
- chlorpromazine, cimetidine, salicylates: incrased valproic acid levels
- phenytoin: displacement of phenytoin from plasma protein
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Term
| adverse effects of valproic acid |
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Definition
- low incidence of adverse effects
- CNS: tremors (at high doses), sedation, HA, diplopia, dizziness
- alopecia
- fatal heptotoxicity (primary adverse rxn), nausea, GI distress, weight gain
- thrombocytopenia, alterations in platelet aggregation
- admin w/ food may delay absorption
- blood levels don't correlate well w/ effects
- caution in pts using ASA/NSAIDs (inhibition of platelets aggregation)
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Term
antiepileptic drugs: benzodiazepines |
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Definition
diazepam (Valium) lorazepam (Ativan) - classified as sedative-hypnotic agents
- both antiepileptic & anxiolytic properties that reduce seizures & anxiety
- produce all levels of CNS depression ranging from mild sedation to coma, depending on the dose ("minor tranquilizers")
- used for acute attacks, not maintenance
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Term
| pharmacotherapeutics of benzodiazepines |
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Definition
- suppress seizure activity by producing GABA - inhibitory neurotransmitter
- management of status epilepticus, severe recurrent seizures & ETOH withdrawl seizures
- parenteral diazepam & lorazepam - drugs of chice in treating status epilepticus
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Term
atypical drugs ethosuximide (Zarontin) |
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Definition
- drug of choice for absence seizures (many pediatric pts)
- inactive against grand mal & partial
- mechanism of action unknown
- well tolerated
- generally devoid of serious side effects or drug interactions (does not induce P-450 enzyme synth)
- most common side effect: GI upset (irritating to the stomach): some drowsiness & dizziness possible
- rarely can cause bone marrow suppression, renal & hepatic damage
- Therapeutic levels: 40-100
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Term
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Definition
- a disturbance in mood or affect
- common, debilitating, life threatening illness that can be successfully treated
- can be MILD, MODERATE, SEVERE; duration of untreated episodes ranges from 6-24mo; episodes continue in up to 80% of untreated pts
- 10-14mil people in the US are depressed in any one year; affects 2-4% of the population; seen in 5-10% of pts in the primary care setting; during their lifetime, 1 in 8 people may require tx for depression
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Term
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Definition
USPSTF recommendations (May 2002) affirmative response to two questions may be as efective as using longer screening measures or may indicate the need for the use of more in-depth diagnositic tools "over the past two weeks, have you ever felt down, depressed, or hopeless?" "over the past 2 weeks, have you felt little interest or pleasure in doing things?" |
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Term
types of depressive disorders: Major Depressive Disorder (MDD) (Major Depression) |
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Definition
- lasts at least 2 weeks, marked by depressed mood, anhedonia (no pleasure in anything); symptoms include loss of appetite, weight loss, psychomotor agitation, insomnia, fatigue, feelings of worthlessness or guilt, diminished ability to think or concentrate recurrent thoughts of death or suicide
- high co-morbidity w/ anxiety disorders (58%), substance abuse disorder (38.6%)
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Term
types of depressive disorders: Dysthymic Disorder |
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Definition
- onset of depressive symptoms less discreet and acute, the experience more chronic in nature
- greatly underdiagnosed; characterized by chronic mild-to-moderate depression lasting about 2 hrs or longer (1yr in kids)
other depressive disorders: substance-induced depressive disorder, season affective disorder, bipolar disorder, postpartum depression, atypical depression
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Term
| pathophysiology of depression |
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Definition
- genetic factors
- personality and environmental factors
- biochemical abnormalities
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Term
monoamine hypothesis (biological basis of depression) pharmacological targets |
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Definition
- increased synaptic serotonin levels (major)
- increased synaptic NE levels
- block of specific serotonin receptors
stimulation (agonism) of the 5-HT (serotonin) 1A (depression) receptor is currently believed to be the mechanism mediating the antidepressant efficacy of antidepressants |
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Term
treatment for depression nonpharmacologic treatment |
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Definition
- cognitive behavioral therapy & interpersonal psychotherapy (best/first approach)
- electroconvulsive therapy (ECT) (for those that don't respont to therapy/meds)
- transcranial magnetic stimulation
- vagus nerve stimulation (VNS)
- deep brain stimulation (DBS)
- complimentary therapies
- hypericum perforatum - St. John's wort
- useful in depression of mild intensity
- should not be used by pts taking SSRIs - both agents increase serotonin levels and could cause overdose
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Term
pharmacologic treatment of depression tricyclic antidepressants (TCAs) |
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Definition
amitriptyline - block the reuptake of monoamine neurotransmitters, exerting influence predominately on NE & serotonin: block cholinergic, dopaminergice, histaminergic, and alpha1 and alpha2 adrenergic receptors
- therapeutic response may take 3-4wks or longer to occur
- effective & long clinical experience: main problem side effects:
- sedation, orthostatic hypotension, constipation, dry mouth, urinary hesitancy, tremor, tachycardia, cardiac a rrhythmias, blurred vision, LETHAL OVERDOSES
- most side effects subside after few weeks; persistence of anticholinergic side effects can e minimized by adding cholinergic smooth-muscle stimulants
- obtain EKG before therapy initiation & after four weeks of TCA tx
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Term
| contraindications of TCAs |
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Definition
- pts during the acute recovery phase following an MI or for those w/ severe CAD
- pts w/ hyperthyroidism & those who are undergoign thyroid hormone therapy (b/c of possible cardiotoxic effects)
- current use of MAO inhibitors
- pts w/ benign prostatic hypertrophy, seizure disorders & narrow-angle glaucoma
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Term
| drug interactions with TCAs |
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Definition
- use of other CNS depressants (barbiturates, opioids, alcohol) can increase CNS depression
- smoking may lower plasma conc of TCAs
- when cimetidine, SSRIs, OCs are given together w/ TCAs, TCA blood levels & the risk of adverse effects are increased
- concurrent use of TCAs and MAO inhibitors may cause extreme excitation, hyperpyrexia & seizures
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Term
pharmacologic treatment for depression: selective serotonin reuptake inhibitors (SSRIs) |
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Definition
sertraline (Zoloft) - mechanism of action complex & includes inhibition of serotonin neurotransmission; block uptake of serotonin by presynaptic neuron, making more available at postsynaptic receptor; initial overstimulation
- first-line agents
- also have other psychiatric application: obsessive compulsive disorde,r panic disorder, bulimia
- advantages: few anticholinergic effects, non-sedating, non-fatal in overdose
- takes up to 10-21 days to notice changes in symptoms: full therapeutic effect in up to 6 wks
- side effects: sexual dysfuction (esp Zoloft), insomnia, anorexia (initially), nausea, diarrhea, weight gain (loss of a sence of satiety & reduction in metabolism)
- Discontinuation Syndrome: flulike symptoms (taper doses to avoid this)
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Term
| drug interactions with SSRIs |
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Definition
- can be significant enzyme inhibitors of the P450 system of hepatic metabolism (e.g. carbamzepine)
- serotonin syndrome can develop in pts taking greater than or equal to 2 drugs that affect serotonin system (MAOIs, TCAs, sympathomimetics - ephedrine)
- Citalopram & sertraline cause less inhibition of the cytochrome P-450 - good for pts taking multiple drugs
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Term
| contraindications of SSRIs |
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Definition
- hypersensitivity
- caution in lactation/pregnancy (cat C)
- concurrent use w/ MAOIs due to risk of hypertensive crisis or "serotonin syndrom" (hyperthermia, autonomic instability, rigidity, myoclonus, confusion, delirium, coma)
- pts w/ hepatic/renal dysfunction
- safety for use in kids is not established
- caution in elderly
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Term
| drug interactions with SSRIs |
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Definition
- cimetidine (Tagamet): increased antidepressant
- MAOIs: possible hypertensive crisis and syndrome of autonomic instability
- TCAs: elevated plasma levels and increased toxicities
when regimen is changed from MAOIs to SSRIs, the pt should be off the MAOI for at least 14 days before initiation of the SSRI: be aware that when the med regimen goes from SSRIs to MAOIs, a longer period (5 wks) off SSRI is needed between the discontinuation of the SSRI and the initiation of the MAOI |
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Term
| overdose of SSRIs is considered ____dangerous than a TCA overdose because: |
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Definition
less dangerous b/c SSRIs are not cardiotoxic |
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Term
pharmacological treatment for depression: monoamine oxidase (MAO) inhibitors |
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Definition
tranylcypromine (Parnate) - block or diminish the actions of MAO, an enzyme that is widely distributed throughout the body w/ the highest conc in the brain, liver, and kidneys
- in the neuron, MAO functions as a "safety valve" & inactivates any excess of the monoamine neurotransmitters (NE, E, dopamine, serotonin)
- when the enzyme is inhibited, the neurotransmitters are available within the synapse, aiding impulse transimission between pre-and post-synaptic neurons
- MAO in the liver and intestine inactivates amines that are present in foods and drugs, and when this is inhibited, the biogenic amines become more available to exert their action
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Term
| parmacotherapeutics of MAOIs |
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Definition
- tx of major depression unrelieved by TCAs, SSRIs, or miscellaneous agents; although MAOIs are considered to be as effective as other antidepressants, they are not the drug of first choice for major depression due to their potential adverse and hazardous effects
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Term
| contraindications of MAOIs |
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Definition
- known sensitivity to MAOIs
- hyperthyroidism
- congestive heart failure or other CV diseases
- hypertension
- pts over 60 or under 16 yrs old
- may drugs as well as foods containing tyramine are contraindicated w/ concurrent MAOI use due to the possible development of either hypertensive effect, severe anticholinergic effect, or profound CNS depression
- tyramine is an amino acid that is a precursor to dopamine, E, and NE; it promotes the release of NE from sympathetic nerve, resulting in hypertensive cdrisis when MAOIs are used; avoid tyramine-containing foods for several d ays before regimen begins, throughout tx, and for 2 wks after discontinuation
- drug interaction:
- b/c there are so mnay drug interactions, no drugs should be added to the pt's regimen w/o consideration of the MAOI interaction
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Term
| nursing considerations for MAOIs |
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Definition
- teach pt dietary/medication precaution required during regimen
- access to MAOIs should be limited to prevent self-administered overdose
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Term
pharmacological treatment of depression: buproprion (Wellbutrin) |
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Definition
- affects both NE & dopamine neurotransmission, leaving the serotonin system unaffected
- advantages: shown to be effective in tx of ADD & smoking cessation; non-sedating, limited drug interaction problems; rare sexual dysfunction
- disadvantages: significant incidence of seizures as an adverse effect in overdose, about 4x that of other antidepressants; it is of specific concern for pts w/ a h/o seizures, head injury, anorexia, or bulimia (secondary to electrolyte imbalances)
- insomnia
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Term
pharmacological treatment of depression: mood stabilizing drugs/animanic agents |
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Definition
lithium carbonate (Eskalith, Lithane) lithium cytrate syrup (Cibalith-S) - mania: elevated mood w/ grandiose ideas, expansiveness, pressred speech, flight of ideas, decreased sleep, increased activity
- lithium = drug of choice for long-term tx of bipolar disorder (manic-depression); the drug of choice for tx of the manic phase, anthough both episodes respond
- also used as an adjunct w/ antidepressants to treat major depression and with antipsychotics to tx schizophrenia
- specific mechanism of action is unknown
- give PO & ion is excreted by the kidney
- pts w/ impaired kidney functions can develop toxic levels of lithium salts
- there is a direct relationship between Na intake & lithium excretion; low Na intake slows lithium excretion & leads to toxicity; excessive Na intake lowers lithium levels
- lithium salts: very toxic; TI = very low; therapeutic levels are 1-1.5 in the acute manic pahse; for maintenance, the levels should be 0.6-1.2; 2.0 = max serum level
- PO preps are rapidly absorbed, peak serum levels are reached in 1-2hrs; clinical response is noted in 1 week or longer; complete response usually takes 3 weeks; the lithium therapy is continued for yers in bipolar disorder
- until therapeutic levels are achieved,symptoms of mania may be controlled by antipsychotics: chlorpromazine
- Lithium causes no noticeable effect on normal individuals, it is not sedative, a euphoriant, or depressant
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Term
| contraindications of mood stabilizing drugs (lithium) |
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Definition
- elderly - lower dose (decreased renal & CV function)
- severe renal or CV disease
- Na depletion that could occur w/ diuretic admin, dehydration, or low Na diet will cause increased lithium levels & possible toxicity
- teratogenic
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Term
| drug interactions with mood stabilizing agents (lithium) |
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Definition
- antipsychotics, carbamzepine, diuretics, indomethacin, ibuprofen, methyldopa, pheytoin: increased toxic effects of lithium
- Benzodiazepines: life-threatening hypothermia
- Haldol: severe encephalopathic symptoms such as parkinsonism, dyskinesia, and dementia
- neuromuscular blockers: prolonged effects of these
- sympathomimetics: reduced pressor effects
- urinary alkalinizers (antacids, caffeine, NaCl, sodium bicarb) - decreased effects of lithium
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Term
| adverse effects of mood stabilizing agents (lithium) |
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Definition
- CNS:
- mild: hand tremors, fatigue, muscle weakness, lethargy
- moderate: coarse hand tremors, confusion, incoordination, increased lethargy, muscle hyperirritability
- severe: ataxia, slurred speech, fasciculation, extrapyramidal symptoms, blurred vision, seizures, coma
- CV: ECG changes and hypotension
- GI: anorexia, nausea, vomiting, diarrhea, increased thirst, gastritis, increased salivation, indigestion, flatulence, taste distortion, salty taste in mouth
- GU: polyuria
- renal: albuminuria, oliguria, glycosuria, hyperkalemia
- derm: pruritus, rash, thinning of hair, acne, cutaneous ulcerations
- endo: hypothyroidism, hyperglycemia, hyperparathyroidism, nephrogenic diabetes insipidus
- EENT: worsening of cataracts, eye irritation
- most pts experience some adverse effects from admin of lithium, but toxicity usually depends on dose and length of therapy; development of toxic symptoms is gradual; usually starts from nausea, gastric upset, fine tremors, urinary frequency
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Term
| nursing considerations for lithium |
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Definition
- admin PO in both liquid and tablet form (also sustained-released)
- instruct pt to never double dosage if a dose is missed but contact physician immediately for instructions
- take w/ meals/milk
- with normal renal function, 10-12 days may be required for lithium to be completely clear of body
- advice pt to carry medicalert card
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Term
| antipsychotic agents/ neuroleptic drugs/major tranquilizers/antischizophrenic drugs |
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Definition
- used primarily to tx psychotic states like schizophrenia, delusional disorder & other hallucinatory states
- block various receptors including cholinergic, adrenergic, serotoninergic, muscarinic & histamine receptors
- antipsychotic actions are thought to be due to blocking of dopamine receptors in the CNS, particularly the D2 receptors in the mesocortical and mesolimbal systems of the brain
- drug's potency parallels its affinity for D2 receptors
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Term
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Definition
- particular type of psychosis, that is mental disorder caused by some inherent dysfunction of the brain
- characterized by delusions, hallucinations (often in form of voices), and thinking/speech disturbances
- common affliction, occuring in 1% of population, or at about the same incidence as DM
- most commonly affects young adults
- strong genetic predisposition & reflects some fundamental biochemical abnormality, maybe overactivity of the mesolimbic dopaminergic neurons
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Term
| neuroleptic drugs are classified as either tranditional or nontraditional (atypical) antipsychotics |
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Definition
- traditional antipsychotics are categorized according to their potency (high, medium, or low) or their strucutre
- potency refers to size of the dose & achievement of therapeutic effect; also has implications re: the inceidence of anticholinergic & extrapyramidal symptoms (EPS)
- management of psychotic disorders can typically be achieved by familiarity w/ the effects of one or two drugs in each class
- traditional antipsychotics are all considered equivalent in efficacy; there is no "perfect" antipsychotic, b/c all produce severe adverse effects; high potency drugs are more likely to produce extrapyramidal adverse effects, while low potency produce sedation & hypotension; drug of choice is the one that pt can tolerate
- antipsychotic drugs do not cure psychosis; suppress or minimize symptoms
- they are no addictive, even w/ overdose; have high TI & can be taken in high doses w/ little risk
- optimum therapeutic effects may take up to 6-7wks
- highly pipophilic & protein bound so they accumulate in body tissues; drug efefcts continue for weeks or months after last dose
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Term
| examples of antipsychotic agents |
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Definition
- low potency: chlorpromazine (Thorazine)
- high potency: haloperidol (Haldol)
- atypical: risperidone (Risperdal)
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Term
extrapyramidal side effects of antipsychotics (75-80% of pts, both high and low potency) |
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Definition
- acute dystonia (onset 1-5 days)
- spasm of muscles of tongue, face, back
- tx with benadryl
- parkisonism (onset 5-30 days)
- bradykinesia, tremor, gait, "pill rolling"
- tx with benadryl
- akathisia (onset 5-60 days)
- resless,compulsive, anxiety
- tx w/ reduced dose ore switch to low-potency drug
- tardive dyskinesia (onset month-yrs)
- oral-facial dyskinesias
- tx w/ prevention (can be irreversible)
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Term
neuroleptic malignant syndrome |
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Definition
neuroleptic malignant syndrome (NMS) is a rare, idiosyncratic rxn thought to be caused by extreme dopamine receptor blockade at the basal ganglia secondary to antipsychotic therapy characterized by series of symptoms including severe muscle rigidity, hyperthermia, and stupor associated w/ traditional high-potency antipsychotic therapy but can occur w/ any antipsychotic |
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Term
| low, medium, and high potency agents produce similar adverse effects, however, certain effects may occur more commonly with one potency than another: |
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Definition
low potency: EPS, NMS; more commonly anticholinergic effects, sedation, hypotension medium/high potency: more liekly to produce EPS and have less sedative and hypotensive effects; NMS more common in high and long-term therapy |
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Term
| nursing considerations with antipsychotics: |
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Definition
- after IM doses, have pt remain lying in bed for 30 min
- parenteral sol'n may have lemon yellow color
- urine may be pink to red-brown
- protect skin from sun exposure
- avoid ETOH, drugs
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Term
atypical antipsychotic drugs: limitations of the traditional antipsychotics: |
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Definition
- inadequate response in 20-40% of pts
- relapse reate of about 35%/yr
- lack of impact upon neg symptoms very high
- incidence of side effects
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Term
atypical antipsychotic drugs: advantages: |
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Definition
clozaril, zyrexa, respirdol, seroquel, geodon - generally better tolerated (better compliance, fewer relapses)
- much lower observed rate of EPSs
- efficacy against neg symptoms
- efficacy against cognitive impairment
- efficacy against depression and suicide
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Term
| traditional (1st generation) antipsychotics may still be appropriate for: |
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Definition
- pts w/ hx of good response w/o EPS
- pts who ahve responded better to these drugs than the atypicals
- pts who have responded better to depot versus oral
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Term
| indications for atypical (2nd generation) antipsychotics: |
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Definition
- pts experiencing first episode of psychosis or pts w/ no avaiable hx concerning response to antipsychotics
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Term
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Definition
- anxiety: unpleasant state of tension, apprehension, or uneasiness; a fear that seems to arise from an unknown source
- symptoms of severe anxiety: similar to those of fear (tachycardia, sweating, trembling, palpitations); may range from mild to panic
- disorders involving anxiety are the most common mental disturbances
- anxiety disorder incidence in US = 16%
- family providers treat 90% of anxiety pts
- refer < 10% of pts to psychiatry
- elderly have lower incidence, but elderly women more affected than men
- often associated w/ depression
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Term
| primary anxiety disorder types: |
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Definition
generalized anxiety disorder panic disorder OCD PTSD social phobia |
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Term
| pathophysiology of anxiety |
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Definition
- hyperarousal state
- begins in breainstem reticular formation
- Locus Ceruleus (secretes NE)
- dorsal and medial raphe nuclei (secrete serotonin)
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Term
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Definition
- the most widely used anxiolytic drugs
- largely replaced barbiturates in tx of anxiety, since they are more effective & safer
- about 20 benzodiazepine derivatives are available
- essentially, all drugs in the class have the same much of action and clinical effects
- differences exist in pharmacokinetics & hence, there are different indications; it is the pharmacokinetic differences that determine clinical use
- can cause several levels of CNS depression, ranging from sedation to general anesthesia; this effect is dose related
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Term
| examples of benzodiazepines |
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Definition
anxiety: alprazolam (Xanax) seizues: lorazepam anesthesia: lorazepam |
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Term
| pharmacodynamics of benzodiazepines |
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Definition
- bind to GABA receptors & enhance the binding of GABA to its receptor
- reason for increased safety is due to limited supply of GABA
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Term
| pharmacotherapeutics of benzodiazepines |
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Definition
- tx of chronic anxiety, anxiety r/t a crisis event, panic disorder
- to decrease anxiety accompanyingsurgical & diagnostic procedures
- tx of ETOH & drug withdrawal, seizure disorders, sleep disorders
- induction of anesthesia
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Term
| pharmacokinetics of benzodiazepines |
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Definition
- all can be admin PO & taken w/ food to decrease GI upset
- half-life, onset, peak & duration of action vary among specific agents; these agents are highly lipid soluble - cross the BBB
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Term
| drug interactions with benzodiazepines |
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Definition
- other CNS depressants, OTC sleep/cold preps, antihistamines, ETOH: additive effect (these include deepened/prolonged sedative effect, motor impairment, enhanced CNS/respiratory depression, death)
- cigarettes: decreased sedative effect
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Term
| contraindications of benzodiazapines |
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Definition
- hypersensitivity, angle-closure glaucoma, severe respiratory distress
- pregnancy/lactation (unless nothing else avail)
- cross placenta
- beleived to cause fetal anomalies when taken during early stages of pregnancy; may cause fetal dependence w/ resulting withdrawl symptoms in the neonate when taken at the end of the 3rd trimeste; when taken at labor will cause CNS depression in the neionate 1st trimester deformities
- caution in pts w/ h/o ETOH/drug abuse
- caution in elderly or debilitated pts b/c of altered metabolism that may allow then or their metaboites to accumulate in the plasma & lead to excessive sedation & ataxia; the outcome of these common effects is incrased risk of falls & injury
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Term
| adverse effects of benzodiazepines |
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Definition
- GI disturbances (dry mouth, n, constipation)
- most common: drowsiness, sedation, ataxia, dizziness, blurred vision
- hypotension
- incontinence
- psychological/physical dependence can develop of high doses are given over a prolonged period
- abrupt discontinuation results in withdrawl symptoms: confusion, anxiety, agitation, restlessness, insomia, tension (so, taper off)
- those w/ a short 1/2-life induce more abrupt & severe withdrawl reactions than those seen w/ drugs that are slowly eliminated
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Term
| nursing considerations with benzodiazepines |
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Definition
- respiratory distress, apnea, cardiac arrest have been reported w/ IV use - admin slow IV push
- note that withdrawal symptoms are associated w/ abrupt withdrawal of BZDs; gradual tapering is indicated
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Term
nonbenzodiazepine anxiety agents: buspirone (Buspar) |
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Definition
- structurally and pharmacologically unrelated to the BZDs, barbiturates, or other CNS depressants
- do not produce CNS depressant activity of any sedative actions; however, they do lower or alleviate many symptoms of generalized anxiety
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Term
| pharmacotherapeutics of buspirone: |
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Definition
- axiety disorders
- tx of ETOH & substance abuse b/c there is no physical or psychological dependency
- benefits:
- less sedating
- not additive w/ CNS depressants
- preg cat B
- little abuse potential
- no physical dependence
- limitations:
- slow onset
- may take 2 wks for effect
- max effect in 3-6wks
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Term
| contraindications/drug interactions with buspirone |
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Definition
- hypersensitivity
- concurrent use w/ MAOIs
- contraindicated in kids under 18yrs old
- EtOH: increased sedative effects of ETOH
- psychotropic drugs: increased levels of these drugs
- MAOIs: increased BP
- adverse effects: n/dizziness/HAs, restlessness
- take w/ food for increased drug effectiveness
- opimal effects may not appear for 3-4wks
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