Transcript Adverse Effects

Drugs for Degenerative Diseases of the Nervous System
Mitzy D. Flores, MSN, RN
Alzheimer’s
Multiple sclerosis
Parkinson’s disease
Most common degenerative disease of CNS
Progressive loss of brain function
Memory loss, confusion, dementia
 Consists of
• Amyloid plaques
• Neurofibrillary tangles
 Changes found during autopsies
 Structural changes cause loss of
neuron number and function
 Symptoms result from progressive
damage to neurons in hippocampus
• Requires acetylcholine as neurotransmitter
 Slow
memory loss
 Slow dementia symptoms
 Improve activities of daily living
 Improve behavior
 Improve cognition
 Prevent
breakdown of acetylcholine
• Enhances transmission in cholinergic neurons
 Only
slows progression
 Examples
• Donepezil hydrochloride (Aricept)
• Galantamine (Razadyne, Reminyl)
• Rivastigmine tartrate (Exelon)
• Tacrine (Cognex)
 Prototype
drug: donepezil hydrochloride
(Aricept)
 Mechanism
of action: to prevent
breakdown of acetylcholine; enhance
transmission in neurons
 Primary use: slow progression of the disease
 Adverse effects: nausea/vomiting, dizziness
and headache, bronchoconstriction, liver injury
(tacrine(Cognex))
 Assess
baseline vitals
 Monitor for hypotension
 Monitor for change in mental status or
mood
 Monitor for dizziness, insomnia,
anorexia
 Clients with narrow-angle glaucoma
should not take revastigmine (Exelon)
 Take
with food or milk to avoid GI upset
 Take as prescribed
 Teach signs and symptoms of overdose
• Severe nausea/vomiting, sweating, salivation,
hypotension
• Bradycardia, convulsions, increased muscle
weaknesses (including respiratory muscles)
 Antipsychotic
agents
 Anxiolytics
 Mood
stabilizers
Demyelination of neurons in CNS
Progressive weakness, visual disturbances
Mood alterations, cognitive deficits
 Etiology
unknown
 Possible causes
• Genetic or microbial factors
 Climate
• Microscopic pathogens
 Demyelination
of neurons in CNS
 Destruction of axons impairs ability of
nerves to conduct electrical impulses
 Inflammation; plaque (scleroses)
 Fatigue
 Heat
sensitivity
 Neuropathic pain; spasticity
 Impaired cognitive ability
 Disruption of balance and coordination
 Visual disturbances; slurred speech
 Bowel and bladder symptoms
 Dizziness; vertigo
 No
cure
 Moderate efficacy
 All drugs have equal efficacy
 Ineffective in late stages
 New drugs under investigation
• Namenda
• Aricept
 Disease
modifying drugs used for
treatment of relapse-remitting MS and
secondary-progressive MS
 Two categories
• Interferon beta (Avonex, Rebif, Bataseron)
• Glatiramer acetate (Copaxone)
 Synthetic protein that simulates myelin basic protein
 Reduce
symptoms and decrease lesions
 Drugs
• Interferon beta (Avonex, Rebif, Betaseron)
• glatiramer acetate (Copaxone)
 Primary
Use: Reduce severity of
symptoms; decrease lesions
 Adverse Effects: flushing, chest pain,
weakness, infection, pain, nausea, joint
pain, anxiety, muscle stiffness
 Used
for progressive-relapsing MS
patients
 Mitoxantrone (Novantrone)
 Primarily a chemotherapeutic drug;
toxicity is concern
 Drug:
Mitoxantrone (Novantrone)
 Primary Use: for MS patients who
have not responded to immunemodulating therapy
 Adverse Effects: toxicity; hair loss;
GI discomfort; allergic symptoms;
blue-green tint to urine
Second most common CNS disease
Progressive loss of dopamine
Tremor, muscle rigidity
Abnormal movement and posture
 Symptoms
known as parkinsonism
• Tremors
• Muscle rigidity
• Bradykinesia
• Postural instability
• Affective flattening
 Primarily
affects muscle movement
 Patients often experience other
health issues
• Anxiety, depression
• Sleep disturbances
• Dementia
• Autonomic nervous system disturbances
 Dopamine
and acetylcholine in
corpus striatum
• Affect balance, posture
• Affect muscle tone, involuntary movement
 Absence
of dopamine
• Allows acetylcholine stimulation
 Restore
balance of dopamine and
acetylcholine in brain
• Dopaminergic drugs
 Dopaminergic adjunct agents
• Anticholinergics (cholinergic blockers)
 Restores
dopamine function
 Blocks acetylcholine
 Clients exhibit extrapyramidal side
effects (EPS) due to lack of
dopamine
• Recall when we give psychotic patients
dopamine inhibitors, they also get EPS
 Restore
balance of dopamine and
acetylcholine
 Dopaminergic examples
• Levodopa (Larodopa),
• Levodopa and carbidopa (Sinemet)
 Prototype
drug: levodopa (Larodopa)
• Mechanism of action: Increases
biosynthesis of dopamine within nerve
terminals
 Primary use: to restore dopamine function
or stimulate dopamine receptors within the
brain
 Adverse
effects: dizziness, lightheadedness, sleep dysfunction, fatigue,
nausea, vomiting, constipation,
orthostatic hypertension, dystonia,
dyskinesia, wearing off effect
 Need liver function studies can cause
hepatoxicity
 Contraindicated
in narrow-angle
glaucoma
 Monitor for hypotension and
tachycardia
 Look for symptoms of drug toxicity
 *Increase
fiber and fluids
 Avoid food and drugs high in
pyridoxine (B6) i.e., protein
 May take several months for full effect
 Abruptly stopping the drug may cause
Parkinsonism crisis
 Take on an empty stomach
 Inhibit enzymes
• Example: Tolcapone (Tasmar)
 Activate dopamine receptors
(dopamine agonists)
• Example: Ropinirole (Requip)
 Cause
dopamine release from nerve
terminals
• Example: Amantadine (Symmetrel)
 Centrally
acting
 Block acetylcholine
• Inhibits overactivity in brain
 Used
in early stages
 Examples
• Benztropine mesylate (Cogentin)
• Triexyphenidyl hydrochloride (Artane)
 Prototype
drug: benztropine mesylate
(Cogentin)
 Mechanism
of action: block acetylcholine;
inhibit overactivity in brain
 Primary use: in early stages of disease
 Adverse effects: dry mouth, blurred vision,
photophobia, urinary retention, constipation,
tachycardia, glaucoma
 Relieve
dry mouth with frequent drinks
or sugarless hard candy
 Take with food or milk to prevent GI
upset
 Avoid alcohol
 Wear dark glasses; avoid bright sunlight
 Do not stop taking abruptly
 Reduce
requirement for L-dopa
 Increase concentration of existing
dopamine; improve motor fluctuations
 Examples:
• entacapone (Comtan)
• tolcapone (Tasmar)
Drugs for Neuromuscular Disorders
 Nervous
 Muscular
 Endocrine
 Skeletal
 Involuntary
contractions of muscles
• Tonic spasm
• Clonic spasm
 Diminished
level of functioning
 Excessive
use or local injury to skeletal
muscle
 Overmedication with antipsychotics
 Epilepsy
 Hypocalcemia pain
 Neurologic disorders
 Immobilization
 Application
of heat or cold
 Hydrotherapy
 Ultrasound
 Supervised exercise
 Massage
 Manipulation
 PT, surgery
 Combination
of
• Analgesics
• Anti-inflammatory agents
• Centrally acting skeletal muscle relaxants
 Inhibit
motor neurons within brain and/or
spinal cord
• Depress CNS effects; alter spinal reflexes
 Reduce
pain; increase range of motion
 Potential to cause sedation
 Prototype
drug: cyclobenzaprine (Flexeril)
 Mechanism of action: inhibits upper-motorneuron activity
• Causes CNS depression, alters simple spinal reflexes
 Primary
use: to treat localized spasms
 Adverse effects: CNS depression, hepatic
toxicity, physical dependence, anticholinergic
effects
 Act
at neuromuscular junction and skeletal
muscle
 Suppress hyperactive reflexes
 Are used for spasms associated with CNS
disorders
 Prototype
drug: dantrolene (Dantrium)
 Mechanism of action: interferes with release
of calcium ions in skeletal muscle
 Primary use: to relieve dystonias and leg
cramps, also used for *malignant hyperthermia
 Adverse effects: hepatic toxicity, muscle
weakness, drowsiness, diarrhea