Categories
Drugs Acting on the Central and Peripheral Nervous Systems Nursing Pharmacology

Antiparkinsonism Agents

Antiparkinsonism Agents

Parkinson’s Disease

  • Progressive chronic neurologic disorder
  • May develop in people of any age
  • Usually affects those who are past middle age and entering their 60s
  • No cure for the disease
  • Therapy is aimed at management of signs and symptoms

Progression of Parkinson’s Disease

  • Lack of coordination
  • Rhythmic tremors
  • Rigidity/weakness
  • Trouble maintaining position or posture
  • Bradykinesia
  • Problem walking
  • Drooling and affected speech
  • Mask-like expressions

Theories About the Cause of Parkinson’s Disease

  • Viral infection
  • Blows to the head
  • Brain infection
  • Atherosclerosis
  • Exposure to certain drugs
  • Environmental factors

The Degeneration of Neurons Leads to Parkinson’s Disease

The Degeneration of Neurons Leads to Parkinson’s Disease
The Degeneration of Neurons Leads to Parkinson’s Disease

 

 

Management of Care for Patients With Parkinson’s Disease

  • Encourage patients to:
    • Be as active as possible
    • Perform exercises
    • Attend to their own care as long as they can
    • Follow drug protocols
  • Caregivers should:
    • Monitor adverse effects
    • Provide encouragement and support

Anticholinergics Used to Treat Parkinson’s Disease

  • Benztropine (Cogentin)
  • Biperiden (Akineton)
  • Diphenhydramine (Benadryl)
  • Procyclidine (Kemadrin)
  • Trihexyphenidyl (Artane)

Anticholinergics

  • Action
    • Block the action of acetylcholine in the CNS to help normalize the acetylcholine–dopamine imbalance
  • Indications
    • Treatment of parkinsonism
    • Relief of extrapyramidal symptoms
  • Pharmacokinetics
    • Absorbed from the GI tract
    • Peak in 1 to 4 hours
    • Metabolized in the liver, excreted by cellular pathways
    • Cross the placenta and enter the breast milk
  • Contraindications
    • Known allergy
    • Narrow angle glaucoma
    • GI obstruction
    • GU obstruction
    • Prostatic hypertrophy
  • Cautions
    • Arrhythmias
    • Hypertension
    • Hypotension
    • Hepatic dysfunction
    • Pregnancy and lactation
  • Adverse reactions
    • Disorientation
    • Confusion
    • Agitation
    • Delirium
    • Nausea, vomiting, and paralytic ileus
  • Drug-to-drug interactions
    • Tricyclic antidepressants
    • Phenothiazines

Levodopa

  • Mainstay of treatment for parkinsonism
  • Precursor of dopamine that crosses the blood–brain barrier, where it is converted to dopamine
  • Almost always given in combination form with carbidopa as a fixed-combination drug (Sinemet)
    • Carbidopa decreases the amount of levodopa needed to reach a therapeutic level in the brain
    • The dosage of levodopa can be decreased, reducing adverse side effects

Other Dopaminergics Used in the Treatment of Parkinsonism

  • Amantadine (Symmetrel)
  • Bromocriptine (Parlodel)
  • Pergolide (Permax)
  • Pramipexole (Mirapex)
  • Ropinirole (Requip)

Dopaminergics

  • Actions
    • Increase the levels of dopamine in the substantia nigra
    • Directly stimulate the dopamine receptors in that area
    • Help to restore the balance between the inhibitory and stimulating neurons
  • Indications
    • Relief of the signs and symptoms of idiopathic Parkinson’s disease
  • Pharmacokinetics
    • Well absorbed from the GI tract and widely distributed in the body
    • Metabolized in the liver and peripheral cells
    • Excreted in the urine
    • Cross the placenta
  • Contraindications
    • Known allergy
    • Angle closure glaucoma
    • GI obstruction
  • Cautions
    • CV disease
    • Bronchial asthma
    • H/O peptic ulcer
    • Urinary tract obstruction
    • Psychiatric disorders
  • Adverse reactions
    • Anxiety
    • Nervousness
    • Headache
    • Blurred vision
    • Arrhythmias
  • Drug-to-drug interactions
    • MAOIs
    • Vitamin B6

Goals of Therapy in Treating Parkinson’s Disease

Goals of Therapy in Treating Parkinson’s Disease
Goals of Therapy in Treating Parkinson’s Disease

Use of Antiparkinsonism Agents Across the Lifespan

Use of Antiparkinsonism Agents Across the Lifespan
Use of Antiparkinsonism Agents Across the Lifespan

Prototype Anticholinergics

Prototype Anticholinergics
Prototype Anticholinergics

Prototype Dopaminergic

Prototype Dopaminergic
Prototype Dopaminergic

Nursing Considerations for Anticholinergics/Antiparkinsonism Drugs

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for Dopaminergic Antiparkinsonism Drugs

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation
Categories
Drugs Acting on the Central and Peripheral Nervous Systems Nursing Pharmacology

Antidepressant Agents

Antidepressant Agents

Affective Disorders vs Depression

  • Affective disorder
    • A person’s mood goes far beyond the normal “ups and downs”
  • Depression
    • Severe and long-lasting feelings of sadness beyond the precipitating event

Signs and Symptoms of Depression

  • Low energy level
  • Sleep disturbances
  • Lack of appetite
  • Limited libido
  • Inability to perform activities of daily living
  • Overwhelming feelings of sadness, despair, hopelessness, and disorganization

Biogenic Amine Theory of Depression

  • Depression results from a deficiency of norepinephrine (NE), dopamine, or serotonin (5HT)
    • Monoamine oxidase (MAO) may break them down to be recycled or restored in the neuron
    • Rapid fire of neurons may lead to their depletion
    • The number or sensitivity of postsynaptic receptors may increase, depleting neurotransmitter levels

Actions of Antidepressant Therapy

  • Inhibits the effects of MAO, leading to increased NE or 5HT in the synaptic cleft
  • Blocks reuptake by the releasing nerve, leading to increased neurotransmitter levels in the synaptic cleft
  • Regulates receptor sites and breakdown of neurotransmitters, leading to an accumulation of neurotransmitters in the synaptic cleft

Classifications of Antidepressants

  • Tricyclic antidepressants (TCAs)
  • MAO inhibitors (MAOIs)
  • Selective serotonin reuptake inhibitors (SSRIs)

Sites of Action for Selected Antidepressants

Sites of Action for Selected Antidepressants
Sites of Action for Selected Antidepressants

 

 

Tricyclic Antidepressants

  • Actions
    • Reduce the reuptake of 5HT and NE into nerves
  • Use
    • All TCAs are similar
    • Choice depends on individual response to the drug and tolerance of adverse effects
  • Indications
    • Relief of symptoms of depression
    • Used for patients with sleep disorders
    • Treatment of enuresis
    • Chronic pain
  • Pharmacokinetics
    • Absorbed from the GI tract
    • Peak in 2 to 4 hours
    • Bound to plasma proteins and lipid soluble
    • Metabolized in the liver and excreted in the urine
    • T½ 8 to 46 hours
  • Contraindications
    • Known allergy, recent MI, myelography, pregnancy, and lactation
  • Cautions
    • CV disease, angle closure glaucoma, urinary retention, and manic depression
  • Adverse reactions
    • Sedation, sleep disturbances, fatigue, hallucinations, ataxia, dry mouth, constipation, nausea, and vomiting
  • Drug-to-drug interactions
    • MAOIs, cimetidine, fluoxetine, ranitidine, and oral anticoagulants

Monoamine Oxidase Inhibitors (MAOIs)

  • Isocarboxazid (Marplan)
    • Used for patients who do not respond to or cannot take newer, safer antidepressants
  • Phenelzine (Nardil)
    • Used for some patients who do not respond to newer, safer antidepressants
  • Tranylcypromine (Parnate)
    • Used for adult outpatients with reactive depression
  • Action
    • Irreversibly inhibit MAOs, allowing norepinephrine, serotonin, and dopamine to accumulate in the synaptic cleft
  • Indication
    • Treatment of patients with depression who are unresponsive to or unable to take other antidepression agents
  • Pharmacokinetics
    • Absorbed from the GI tract
    • Peak in 2 to 3 hours
    • Metabolized in the liver and excreted in the urine
    • Cross placenta and enter breast milk
  • Contraindications
    • Known allergy, pheochromocytoma, CV disease, headaches, and renal or hepatic impairment
  • Adverse reactions
    • Dizziness, excitement, nervousness, mania, hyperreflexia, tremors, confusion, insomnia, agitation, liver toxicity, nausea, vomiting, diarrhea or constipation, anorexia, weight gain, dry mouth, and abdominal pain
  • Drug-to-drug interactions
    • Other antidepressants: hypertensive crisis and coma
    • Methyldopa: sympathomimetic effects increase
    • Insulin or oral antidiabetic agents: additive hypoglycemia
  • Food interactions
    • Tyramine or pressor amines: increase blood pressure

Selective Serotonin Reuptake Inhibitors (SSRIs)

  • The newest group of antidepressant drugs
  • Specifically block the reuptake of 5HT, with little to no known effect on NE
  • Do not have the many adverse effects associated with TCAs and MAOIs
  • Action
    • Inhibit CNS neuronal reuptake of serotonin with little effect on norepinephrine and little affinity for cholinergic, histaminic, or alpha-adrenergic sites
  • Indications
    • Depression, OCD, panic attacks, bulimia, PMDD, posttraumatic stress disorders, social phobias, and social anxiety disorders
  • Pharmacokinetics
    • Absorbed from the GI tract
    • Metabolized in the liver
    • Associated with congenital abnormalities
  • Contraindications
    • Known allergy, pregnancy, lactation, and impaired renal or hepatic function
  • Adverse reactions
    • Headache, drowsiness, dizziness, insomnia, anxiety, tremor, and agitation
  • Drug-to-drug interactions
    • MAOIs
    • TCAs increase therapeutic and toxic effect

Miscellaneous Antidepressants

  • Bupropion (Wellbutrin, Zyban)
  • Mirtazapine (Remeron)
  • Nefazodone (Serzone)
  • Trazodone (Desyrel)
  • Venlafaxine (Effexor)

Use of Antidepressant Agents Across the Lifespan

Use of Antidepressant Agents Across the Lifespan
Use of Antidepressant Agents Across the Lifespan

Prototype Tricyclic Agent

Prototype Tricyclic Agent
Prototype Tricyclic Agent

Prototype MAOIs Agent

Prototype MAOIs Agent
Prototype MAOIs Agent

Prototype SSRI Agent

Prototype SSRI Agent
Prototype SSRI Agent

Nursing Considerations for Tricyclic Antidepressant Agents

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for MAOI Antidepressant Agents

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for SSRI Antidepressant Agents

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation
Categories
Drugs Acting on the Central and Peripheral Nervous Systems Nursing Pharmacology

Anxiolytic and Hypnotic Agents

Anxiolytic and Hypnotic Agents

Types of Anxiolytic and Hypnotic Agents

  • Anxiolytics
    • Prevent feelings of tension or fear
  • Sedatives
    • Calm and make patients unaware of the environment
  • Hypnotics
    • Cause sleep
  • Minor tranquilizers
    • Produce a state of tranquility in anxious patients

States Affected by Anxiolytic and Hypnotic Drugs

  • Anxiety
  • –Feeling of tension, nervousness, apprehension, or fear involving unpleasant reactions to a stimulus
  • Sedation
  • –Loss of awareness and reaction to environmental stimuli
  • Hypnosis
  • –Extreme sedation resulting in further CNS depression and sleep

Sites of Action of Benzodiazepines and Barbiturates

Sites of Action of Benzodiazepines and Barbiturates
Sites of Action of Benzodiazepines and Barbiturates

 

 

Benzodiazepines—Actions

  • Act in the limbic system and the RAS
  • Make GABA more effective
  • Cause interference with neurons firing
  • Lower doses cause anxiolytic effects
  • Higher doses cause sedation and hypnosis

Benzodiazepines—Indications

  • Anxiety disorders
  • Alcohol withdrawal
  • Hyperexcitability and agitation
  • Preoperative relief of anxiety and tension

Benzodiazepines—Pharmacokinetics

  • Well absorbed from the GI tract
  • Peak levels achieved in 30 minutes to 2 hours
  • Lipid soluble and well distributed throughout the body
  • Cross placenta
  • Enter breast milk
  • Metabolized in the liver
  • Excretion is primarily in the urine

Benzodiazepines—Contraindications & Cautions

  • Allergy to benzodiazepines
  • Psychosis
  • Acute narrow angle glaucoma
  • Shock
  • Coma
  • Acute alcohol intoxication
  • Pregnancy

Benzodiazepines—Adverse Effects

  • Sedation
  • Drowsiness
  • Depression
  • Lethargy
  • Blurred vision
  • Confusion
  • Dry mouth
  • Constipation
  • Nausea
  • Vomiting
  • Hypotension
  • Urinary retention

Benzodiazepines—Drug-to-Drug Interactions

  • Increase CNS depression when taken with alcohol
  • Increase in effect when taken with cimetidine, oral contraceptives, or disulfiram
  • Decrease in effect if given with theophylline or ranitidine

Barbiturates

  • Act as a general CNS depressant
  • Inhibit neuronal impulse conduction in the ascending RAS
  • Depress the cerebral cortex
  • Alter cerebellar function
  • Depress motor output

Barbiturates—Actions

  • CNS depressant
  • Inhibit neuronal impulse conduction in the ascending RAS
  • Depress cerebral cortex
  • Depress motor output
  • Cause sedation, hypnosis, anesthesia, and coma

Barbiturates—Indications

  • Relief of the signs and symptoms of anxiety
  • Sedation
  • Insomnia
  • Preanesthesia
  • Seizures

Barbiturates—Pharmacokinetics

  • Well absorbed
  • Reach peak in 20 to 60 minutes
  • Metabolized in the liver
  • Excreted in the urine

Barbiturates—Contraindications & Cautions

  • Allergy to any barbiturate
  • Previous history of addiction to sedative–hypnotic drugs
  • Latent or manifest porphyria
  • Marked hepatic impairment or nephritis
  • Respiratory distress or severe respiratory dysfunction
  • Pregnancy

Barbiturates—Adverse Reactions

  • CNS depression
  • Physical dependency
  • Drowsiness
  • Somnolence
  • Lethargy
  • Ataxia
  • Vertigo
  • Nausea
  • Vomiting
  • Constipation

Barbiturates—Drug-to-Drug Interactions

  • Increase CNS depression when given with alcohol, antihistamines, and other tranquilizers
  • Alter response to phenytoin
  • MAOs increase serum levels and effect
  • Decrease effectiveness of the following drugs:  anticoagulants, digoxin, tricyclic antidepressants, corticosteroids, and oral contraceptives

Other Anxiolytic and Hypnotic Drugs

  • Paraldehyde (Paral): sedates patients with delirium tremens or psychiatric conditions characterized by extreme excitement
  • Meprobamate (Miltown): manages acute anxiety for up to 4 months
  • Chloral hydrate (Aquachloral): produces nocturnal sedation or preoperative sedation
  • Glutethimide (generic), zaleplon (Sonata), and zolpidem (Ambien): short-term treatment of insomnia
  • Antihistamines (promethazine [Phenergan], diphenhydramine [Benadryl]: preoperative medications, and postoperatively to decrease the need for narcotics
  • Buspirone (BuSpar): reduces the signs and symptoms of anxiety without severe CNS and adverse effects

Use of Anxiolytic and Hypnotic Agents Across the Lifespan

Use of Anxiolytic and Hypnotic Agents Across the Lifespan
Use of Anxiolytic and Hypnotic Agents Across the Lifespan

Prototype Benzodiazepines Agent

Prototype Benzodiazepines Agent
Prototype Benzodiazepines Agent

Prototype Barbiturates Agent

Prototype Barbiturates Agent
Prototype Barbiturates Agent

Nursing Considerations for Benzodiazepines

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation

Nursing Considerations for Barbiturates

  • Assessment (history and physical exam)
  • Nursing diagnosis
  • Implementation
  • Evaluation