drug therapy for Parkinson's, urinary spasticity, and disorders requiring anticholinergic drug therapy Flashcards
define parkinson’s disease
what is it and what is it characterized by?
-chronic, progressive, degenerative disorder of the CNS
-characterized by resting tremor, bradykinesia, rigidity, and postural instability
describe the etiology of parkinsons disease
cause of the nerve cell damage is unknown
describe the pathophysiology of parkinson’s disease
where and what neurotransitters are involved?
-progressive destruction of or degerative changes in dopamine producing nerve cells in the substantia nigra in the basal ganglia
-decrease in dopamine and increase in acetylcholine
describe the clinical manifestations of parkinsons disease
-pill rolling movements
-bradykinesia (slow movement)
-akinesia (no movement)
-shuffling gait/stooped posture
-masklike facial expressions/rigidity
-soft voice
what drug therapy is used for patients with parkinson’s disease
dopamine receptor agonsists and COMT inhibitors
-goal is to balance dopamine and acetylcholine
describe levodopa-carbidopa
two meds in one - why?
-most common used for parkinsons
-levodopa changes to dopamine in the brain, carbidopa prevents the breakdown of levodopa in the blood
-this helps correct the neurotransmitter imbalance in the brain
describe the pharmacokinetics of levodopa-carbidopa
-well absorbed in small intestine after oral administration
-primarily excreted in the urine
describe the action of levodopa-carbidopa
-increases the amount of dopamine in the brain
-levodopa is the metabolic precursor of dopamine
describe the use of levodopa-carbidopa
-dopamine receptor agonists
-symptomatic treatment of idiopathic parkinsons, often akinetic symptoms
-tx of serious restless leg syndrome
describe some adverse effects of levodopa-carbidopa
-CNS -> headache, anxiety, drowsiness, hallucinations
-cardiovascular -> orthostatic hypotension, increase or decrease in HR, decrease in BP
-GI -> anorexia, N+V, teeth grinding
-others
what are some contraindications of levodopa-carbidopa
-hypersensitivity, narrow angle glaucoma, melanoma, peptic ulcer disease, HTN
-severe cardiovascular, pulmonary, renal, hepatic, endocrine disorders
what are some nursing implications with levodopa-carbidopa
-preventing interactions
-administering medication
-assessing for therapeutic and adverse effects (know baseline HR and BP and check periodically)
-patient teaching
what are some parts of patient teaching that should be mentioned with levodopa-carbidopa
-do not stop abruptly, must be tapered off
-stop all MAOIs -> cause risk for hypertensive crisis
-do not crush, must be swallowed whole
-can be given with food
-no iron vitamins or increased protein in diet
what are some other drugs in the same class as levodopa-carbidopa
and what consideration should be made?
-amantadine, pramipexole, ropinirole, selegeline
-must be given in conjunction with levodopa-carbidopa
what is the black box warning for levodopa-carbidopa
and what should be checked?
-risk for fulminant fatal acute renal failure
-check BUN, GFR, creatinine, as well as urine output characteristics
why should you check BUN, creatinine, and GFR of a person taking levodopa-carbidopa
all indicators of renal function/failure
black box warning on med is acute renal failure
describe ropinirole
drug class? action? concentration? half life?
-stimulates dopamine receptors in the brain
-same class as levodopa-carbidopa
-steady state concentration on approx 2 days
-40% protein bound
-1/2 life elimination = 6 hours
can ropinirole be taken with levodopa-carbidopa
-yes
-especially when levopa becomes less effective, have to decrease levodopa dose when adding this medication
describe the pharmacokinetics of ropinirole
-well absorbed orally (peak level 1-2 hours)
-metabolized by cytochrome P450 (liver) (pts with hepatic impairment - increase adverse effects)
-renal excretion (alter dose in patients with renal impairment/failure)
describe COMT
what does it play a role in?
plays a role in the metabolism of dopamine and the breakdown of 10% of lepodopa in the body
should tolcapone be given by itself?
like with no other drugs?
nope. tolcapone has to be given with levodopa-carbidopa as an adjunct or add-on therapy
what if tolcapone doesnt work for a patient after three weeks?
discontinued due to the undesirable side effects, but not stopped abruptly bc it has to be tapered off over 2 weeks
describe the pharmacokinetics of tolcapone
-absorbed rapidly and is highly protein bound
-metabolized in the liver
-crosses the placenta
-excreted in the feces and urine
also has 2-3 hour half life
describe the action of tolcapone
inhibits the metabolism of levodopa in the bloodstream, may also inhibit COMT in the brain and prolong the activity of dopamine at the synapse
what is tolcapone used for?
treatment of the signs and symptoms of idiopathic parkinsons disease
what are the adverse effects associated with tolapone
-CNS = disorientation, confusion, hallucination, and psychosis
-cardiovascular = othrostatic hypotension
-GI very sudden severe liver failure
-respiratory
-generalized
look at ALT/AST lab results bc they indicate liver function
name some contraindications of tolcapone
-hypersensitivity
-liver disease
-nontraumatic rhabdomyolysis
-hyperpyrexia
-confusion
what are some nursing implications for tolcapone
-preventing interactions
-administering the medication
-assessing for theraputic and adverse effects
-patient teaching
describe patient teaching for tolcapone
-no MAOIs -> risk for hypertensive crisis
-must taper off, no abruptly stopping
-do not breats feed on this med
-have liver function tests as scheduled
-use caution when operating machinery and avoid alcohol or other CNS depressants
name another drug in the class of tolcapone
entacapone
said to be newer and safer with less side effects
what kind of drug is the combination drug: levodopa carbidopa and entacapone
catechol-o-methyltransferase (COMT) inhibitor and decarboxylase inhibitor/dopamine precursor
what is entacapone
selective inhibitor of COMT, allows for increased levodopa in serum levels
describe the pharmacokinetics of combination drug: levodopa carbidopa and entacapone
-well absorbed in small intestine after oral administration
-primarily excreted in urine
describe the action of combination drug: levodopa carbidopa and entacapone
-levodopa is metabolic precursor for dopamine
-carbidopa inhibits the breakdown of levodopa
-entacapone is a selective inhibitor of COMT that alters levodopa to increase serum concentration
name some adverse effects of combination drug: levodopa carbidopa and entacapone
-GI= diarrhea, N+V, drug indiced colitis
-solmnolence (non interactive behavior)
-dyskinesia (difficulty moving)
-bruxism (teeth grinding)
-suidical ideations
what are some contraindications of combination drug: levodopa carbidopa and entacapone
-hypersensitivity, concurrent use with MAOI
-melanoma, firbrotic complications
what are some nursing implications of combination drug: levodopa carbidopa and entacapone
-preventing interactions
-administering med
-assessing therapeutic and adverse effets
-pt teaching
what is the MOA of anticholinergics
what do they do/block
inhibit the action of acetylcholine in the brain and affects the PNS, often will interact with the muscarinic and nicotinic receptors
describe drug therapy with anticholinergics
-act by occupying receptor sites on target organs innervated by PNS resulting in fewer sites free to respond to Ach
-decreases or eliminates parasympathetic response
-response is dependent on number of receptor sites blocked
what are the symptoms of anticholinergic overdose
-hyperthermia
-mydriasis
-delirium
-tachycardia
-myoclonic movements
-seizures
-coma
-respiratory arrest
-cycloplegia (paralysis of ciliary muscles of the eyes)
name some antocholinergic effects on different locations in the body
-CNS stimulation followed by depression
-increased HR
-bronchodilation and decreased respiratory tract secretions
-decreased GI spasms
-decreased salivary and sweat gland secretions
-ureter and urinary bladder relaxation
-smooth muscle relaxation in gallbladder and bile ducts
define atropine sulfate
-extracted from the belladonna plant or prepared synthetically, is a salt that is very soluble in water
-also classified as a muscarinic antagonist
describe the pharmacokinetics of atropine sulfate
-well absorbed in all forms of administration (IV takes 2-4 mins to work and lasts 4 hrs)
-metabolized in liver
-excreted in urine
what are some uses of atropine sulfate
-tx of bradycardia
-preoperatively (decreases respiratory secretions)
-eye drops (dilates pupils and relieves swelling pain)
-used as an antidote
-used in emergency situations
describe the action of atropine sulfate
blocks the effects of acetylcholine at muscarinic cholinergic receptors that mediate the effects of parasympathetic postganglionic impulses
describe the adverse effects of atropine sulfate
-cardiovascular = tachycardia
-CNS = mydriasis, blurred vision, photophobia, increased IOP
-GI = dry mouth, constipation, paralytic ileus
-GU = urinary retention
paralytic ileus = slowing of the bowel
name some contraindications of atropine sulfate
hypersensitivity, glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, bronchial asthma, bladder neck obstruction, hepatic or renal disease
what are some nursing implications for atropine sulfate
-preventing interactions
-administering med
-assessing for therapeutic and adverse effects
what patient teaching is important with atropine sulfate
-avoid excessive high temperatures, drink water frequently
-rinse mouth frequently and maintain good dental hygiene
-void before taking the medication
-visit ophthalmologist regularly
-notify provider if… fluid intake is greater or less than output, develop a fever, weakness becomes severe
what are some other drugs in the class with atropine sulfate
ipratropium (dilates constricted bronchioles), scopolamine (motion sickness patch), tiotropium bromide
define benztropine mesylate
newer synthetic drug that is more selective for muscarinic receptors in the CNS
what is benztropine mesylate used for?
adjunctive therapy of all forms of parkinsons
describe the pharmacokinetics of benztropine mesylate
-can be administered orally of parenterally (IV)
-absorbed in GI tract
-metabolized in the liver
-excretion is unknown (watch kidney function no matter what)
describe the action of benztropine mesylate
-helps to normalize the imbalance of cholinergic and dopaminergic neurotransmission in the basal ganglia
describe the adverse effects of benztropine mesylate
-CNS = confusion, hallucinations, memory loss, agitation, and heaviness of the limbs
-cardiovascular = tachycardia, orthostatic hypotension
-general =muscle movement issues, dry mouth and decreased sweating, elevated temperature
what are some contraindications of benztropine mesylate
glaucoma, GI issues, myasthenia gravis, cardiovascular issues
what are some nursing implications associated with benztropine mesylate?
-preventing interactions
-administering medication
-assessing for therapeutic and adverse effects (monitor I+O, bowel sounds, and BM occurrence)
describe important points with patient teaching related to benztropine mesylate
-avoid alcohol, sedatives, and OTC medications including cough or cold remedies
-void before taking medication
-notify provider if… fluid intake is greater or less than output, weakness becomes severe, develop a fever
-drink water frequently and maintain good dental hygiene
-avoid excessively high temperatures
what is oxybutynin used for?
bladder instability in patients with uninhibited and reflex neurogenic bladder, overactive bladder, incontinence, urgency, and frequency
describe the pharmacokinetics of oxybutynin
-can be administered in oral and transdermal forms
-metabolized in the liver and excreted in urine
describe the action of oxybutynin
acts directly on the smooth muscle and inhibits the effects of acetylcholine at muscarinic receptors (antispasmodic/antimuscarinic)
describe th adverse effects of oxybutynin
CNS = drowsiness, dizziness, blurred vision
-dry mouth, nausea, urinary hesitancy, and decreased sweating
same as any other anticholinergic
what are some contraindications of oxybutynin
hypersensitivity, GI issues, glaucoma, myasthenia gravis, cardiovascular instability, urinary retention
what ae some nursing implications of oxybutynin
-preventing interactions
-administering the medication (look at dosage, do not crush)
-assessing for therapeutic and adverse effects (check renal function and track urination frequency before and after medication)
describe patient teaching with oxybutynin
-have periodic bladder examinations
-drink water frequently and avoid excessive high temperature
-notify provider if… fluid intake is greater or less than output or if fever is developed
-do not cut, crush, or chew medication
-if using patch, apply to dry intact skin and remove old on before applying new
