Introduction to Clinical Pharmacology Chapter 18- Central Nervous System Stimulants

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Introduction to Clinical Pharmacology

Chapter 18-Central Nervous System

Stimulants

Introduction to Clinical Pharmacology

Chapter 18-Central Nervous System

Stimulants


CNS Stimulants: ActionCNS Stimulants: Action

• Analeptics:

– Increase depth of respirations

• Caffeine:

– Cardiac stimulation; dilation of coronary; peripheral blood vessels; constriction of cerebral blood vessels; skeletal muscle stimulation


CNS stimulants: Actions (cont’d)CNS stimulants: Actions (cont’d)• Modafinil:

– Exact mechanism of action is not known, but drug is thought to bind to dopamine thereby reducing number of episodes

•Amphetamines (sympathomimetics):

– Elevate blood pressure; wakefulness; increase or decrease-pulse rate; produce euphoric state

• Anorexiants: Suppress appetite


CNS Stimulants: UsesCNS Stimulants: Uses• CNS stimulants-treatment:

– *Attention deficit hyperactivity disorder

– *drug-induced respiratory depression

– postanesthesia respiratory depression without reduction of analgesia

– narcolepsy

– *sleep apnea

– exogenous obesity

– fatigue


CNS Stimulants: Adverse ReactionsCNS Stimulants: Adverse Reactions

• Neuromuscular reactions:

– Excessive CNS stimulation; headache; dizziness; apprehension; disorientation; hyperactivity

• Other:

– Nausea; vomiting; cough; dyspnea; urinary retention; tachycardia; palpitations; anorexia


CNS Stimulants: ContraindicationsCNS Stimulants: Contraindications• CNS stimulants contraindicated:

– In patients with known hypersensitivity; convulsive disorders; ventilation mechanism disorders

• Nurse should not administer CNS stimulants to patients with:

– Cardiac problems; severe hypertension; hyperthyroidism

• Amphetamines:

– *Contraindicated in glaucoma

– *Amphetamines and anorexiants should not be taken concurrently or within 14 days of antidepressant medications


CNS Stimulant: InteractionsCNS Stimulant: Interactions

Interactant drug Effect of interaction

Anesthetics Increased risk of cardiac arrhythmias

Theophylline Increased risk of hyperactive behaviors

Oral contraceptives and modafinil

Decreased effectiveness of the oral contraceptive


Nursing Process: AssessmentNursing Process: Assessment• Preadministration assessment:

– Respiratory depression:

•Initial assessments: Blood pressure, pulse, respiratory rate

•Note: Depth of respirations; any pattern to respiratory rate

•Review: Recent laboratory test results


Nursing Process: AssessmentNursing Process: Assessment• Preadministration assessment (cont’d):

– Attention deficit hyperactivity disorder:

•Amphetamine prescribed: Weigh patient and take blood pressure; pulse; and respiratory rate

•Child with ADHD: Observe for patterns of abnormal behavior

•Record summary: Document/chart client’s behavior; provides comparison/future changes


Nursing Process: AssessmentNursing Process: Assessment

• Preadministration assessment (cont’d):

– Obesity:

•Anorexiant or amphetamine:

•Used for outpatient use

•Obtain and record:

•Blood pressure; pulse; respiratory rate; weight- before therapy starts and at each outpatient visit


Nursing Process: AssessmentNursing Process: Assessment

• Ongoing assessment

– Respiratory depression:

•Take blood sample: For arterial blood gas analysis; determine effectiveness of analeptic

•Observe: Adverse drug reaction; report occurrence immediately to PHCP


Nursing Process: Nursing Diagnosis and PlanningNursing Process: Nursing Diagnosis and Planning• Disturbed sleep pattern; ineffective

breathing pattern; imbalanced nutrition

• Expected outcomes:

– Depends on reason for administration

– Optimal response to therapy

– Support patient needs: Manage adverse drug reactions

– Understanding: Drug regimen


Nursing Process: ImplementationNursing Process: Implementation

• Promoting an optimal response to therapy:

– Amphetamines: Used for short-term treatment of exogenous obesity

•Long term use: Causes addiction and abuse



• Monitoring and managing patient needs:

– Disturbed sleep patterns:

•CNS stimulant therapy: Causes insomnia; administer early in the day

•Avoid: Coffee, tea, cola drinks, chocolate

•Vital signs: Checked every 6 to 8 hours

•Adverse reactions: Amphetamine use may require discontinuation of drug



• Monitoring and managing patient needs (cont’d):

– Ineffective breathing pattern:

•Use of analeptic drugs for respiratory stimulation: Enhances breathing pattern

•Doxapram: Causes urinary retention; measure intake and output, notify PHCP if patient unable to void or bladder appears distended


GeriatricsGeriatrics

• *Older adults are more sensitive to CNS stimulants and may exhibit anxiety, nervousness, insomnia, mental confusion




– Imbalanced nutrition: Less than bodily requirement

•Adverse reactions: Use of CNS stimulants-child with ADHD decreases appetite

•Long-term treatment: CNS stimulants-retards growth in children




– Imbalanced nutrition (cont’d):

•Monitor: Weight, growth patterns in children on long-term treatment with CNS drugs

•Frequently check: Height, weight of child to monitor growth

•PHCP may periodically interrupt therapy to monitor effectiveness of therapy



• Educating the patient and family:

– Therapeutic regimen, adverse drug reactions are explained to patient and family

– Emphasize: Need to follow recommended dosage schedule

– Develop a teaching plan



• Educating the patient and family (cont’d):

– Additional teaching points:

•Attention deficit hyperactivity disorder

•Administer drug in morning 30 to 45 minutes before breakfast and before lunch.

•Monitor and record behavior of child



• Educating the patient and family (cont’d):

– Additional teaching points (cont’d):

•Narcolepsy:

•Record: Number of times per day periods of sleepiness occur

• Amphetamines and anorexiants:

•Avoid: coffee, tea, carbonated beverages containing caffeine


Nursing Process: EvaluationNursing Process: Evaluation

• Child’s behavior, school performance-improves

• Weight loss is achieved

• Respiratory depression: Reversed

• Fewer episodes of inappropriate sleep patterns reported

• Adverse reactions are identified, reported, and managed

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Introduction to Clinical Pharmacology Chapter 18- Central Nervous System Stimulants