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Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Chapter 22
Drugs Stimulating the Central Nervous System
Chapter 22
Drugs Stimulating the Central Nervous System
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Physiology Physiology • The CNS is responsible for providing control systems and
surveillance for many vegetative and conscious functions.
• The control of respiration occurs in the pons and medulla.
• At a synaptic level in the CNS, normal arousal mechanisms are affected through presynaptic release of neurotransmitters.
• CNS stimulants may provoke an increased release of neurotransmitters, a decreased reuptake of neurotransmitters, or an inhibition of postsynaptic enzymes.
• The result is a heightened postsynaptic response, leading to increased arousal.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Regulatory Centers of the BrainRegulatory Centers of the Brain
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Narcolepsy Narcolepsy
• Narcolepsy is characterized by irresistible bouts of rapid eye movement (REM) sleep during nonsleep cycles.
• Associated features include disturbed nocturnal sleep and REM sleep disturbances.
• Additional symptom of cataplexy is a brief, sudden loss of motor control.
• Hypnagogic hallucinations are auditory, visual, or kinesthetic sensations without stimuli, appearing in the transition period between wakefulness and sleep.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Attention Deficit Hyperactivity Disorder Attention Deficit Hyperactivity Disorder
• Attention deficit hyperactivity disorder (ADHD) is the most prevalent chronic health issue affecting school-aged children.
• It is characterized by a persistent pattern of inattentiveness, hyperactivity, and impulsivity.
• Current research suggests that ADHD has a biologic basis.
• The management of ADHD is complex but usually involves pharmacotherapy with one or more of the CNS stimulants combined with behavior modification.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Overweight and Obesity Overweight and Obesity
• Obesity has become one of the major health issues in the United States.
• Overweight refers to an excess of body weight compared with set standards. The excess weight may come from muscle, bone, fat, or body water.
• Obesity refers specifically to having an abnormally high proportion of body fat.
• Weight regulation is multifactorial.
• Treating obesity involves a combination of different methods, including modifying eating behavior, implementing and maintaining an exercise program, and using adjunctive pharmacologic therapy to reduce appetite.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Respiratory Stimulation Respiratory Stimulation
• In patients at risk for postoperative pulmonary complications, respiratory depression may be a complication arising from chronic obstructive lung disease and frequent hypercapnia.
• Hypercapnia is a buildup of carbon dioxide levels that may result from pulmonary compromise.
• Preterm infants may experience hypercapnia because of their immature respiratory systems.
• Pharmacologic management of respiratory depression includes administering CNS stimulants, such as caffeine and doxapram.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Centrally Acting CNS Stimulants Centrally Acting CNS Stimulants
• The centrally acting CNS stimulants are drugs that stimulate the CNS directly or indirectly.
• This group of drugs includes the amphetamines, methylphenidate, pemoline, and cocaine.
• Prototype drug: dextroamphetamine (Dexedrine)
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Dextroamphetamine: Core Drug Knowledge Dextroamphetamine: Core Drug Knowledge
• Pharmacotherapeutics
– Treatment of narcolepsy, ADHD, and obesity
• Pharmacokinetics
– Administered: oral. Metabolism: liver. Excreted: kidneys. Onset: 20 to 60 minutes. Duration: 5 hours
• Pharmacodynamics
– The exact mechanism of action is unknown.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Dextroamphetamine: Core Drug Knowledge (cont.)Dextroamphetamine: Core Drug Knowledge (cont.)
• Contraindications and precautions
– Cardiac disease, hyperthyroidism, and hypersensitivity
• Adverse effects
– Sudden death, stroke, MI, decreased appetite, rebound irritability, depression, headache, and jittery feeling
• Drug interactions
– Multiple drug interactions
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Dextroamphetamine: Core Patient Variables Dextroamphetamine: Core Patient Variables • Health status
– Evaluate for preexisting conditions.
• Life span and gender– Pregnancy Category C drug
• Lifestyle, diet, and habits– Assess for consumption of caffeine.
• Environment– Assess the environment where the drug will be given.
• Culture and inherited traits– Determine if alternative therapies are used by the
patient.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Dextroamphetamine: Nursing Diagnoses and Outcomes Dextroamphetamine: Nursing Diagnoses and Outcomes • Disturbed Sleep Pattern related to drug effects or caffeine
use
– Desired outcome: The patient maintains normal sleep patterns through proper use of sleep hygiene measures and bedtime (hour of sleep [HS]) sedation.
• Delayed Growth and Development related to drug effects
– Desired outcome: The patient maintains a normal growth and development profile.
• Disturbed Sensory Perception related to drug response
– Desired outcome: The patient remains free from sensory and perceptual disturbances.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Dextroamphetamine: Nursing Diagnoses and Outcomes (cont.)Dextroamphetamine: Nursing Diagnoses and Outcomes (cont.)
• Imbalanced nutrition: Less than body requirements, related to amphetamine abuse and anorexia
– Desired outcome: The patient maintains adequate nutrition.
• Nonadherence to Therapeutic Regimen related to lack of motivation, poor self-image, or negative effects of the prescribed drug
– Desired outcome: The patient adheres to the drug regimen.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Dextroamphetamine: Planning and InterventionsDextroamphetamine: Planning and Interventions
• Maximizing therapeutic effects
– Administer with food in the morning and no fewer than 6 hours before bedtime
• Minimizing adverse effects
– Monitor for adverse effects.
– Monitor for rebound irritability and depression.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Dextroamphetamine: Teaching, Assessment, and EvaluationsDextroamphetamine: Teaching, Assessment, and Evaluations
• Patient and family education
– Discuss the importance of adherence to dosage schedule.
– Discuss adverse effects of the drug.
• Ongoing assessment and evaluation
– Monitor periodic growth and development data for children throughout therapy.
– Monitor for adverse effects.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
QuestionQuestion
• Dextroamphetamine has which of the following effects on glucose levels?
– A. Increased
– B. Decreased
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
AnswerAnswer
• A. Increased
• Rationale: Dextroamphetamine can cause increased serum glucose levels. This is the reason why it is important for diabetic patients on this medication to monitor glucose levels more closely.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Anorectic Agents Anorectic Agents
• Obesity is a complex problem that is very difficult to treat.
• Although drug therapy is helpful, drugs alone cannot manage weight loss.
• Diet and exercise are equally important.
• Prototype drug: phentermine (Adipex-P)
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Phentermine: Core Drug Knowledge Phentermine: Core Drug Knowledge
• Pharmacotherapeutics
– Manages obesity by promoting weight loss
– DEA Schedule IV drug
• Pharmacokinetics
– Administered: oral. Metabolism: liver. Excreted: kidneys
• Pharmacodynamics
– Direct stimulation of satiety center in the hypothalamic and limbic regions
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Phentermine: Core Drug Knowledge (cont.)Phentermine: Core Drug Knowledge (cont.)
• Contraindications and precautions
– Arteriosclerosis, hypertension, glaucoma, cardiac arrhythmias
• Adverse effects
– Hypertension, constipation, insomnia, headache, and dry mouth
• Drug interactions
– MAOIs and SSRIs
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Phentermine: Core Patient Variables Phentermine: Core Patient Variables
• Health status
– Assess for contraindications to therapy.
• Life span and gender
– Pregnancy Category C drug
• Lifestyle, diet, and habits
– Assess diet and make modifications.
• Environment
– Assess the environment where the drug will be given.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Phentermine: Nursing Diagnoses and Outcomes Phentermine: Nursing Diagnoses and Outcomes
• Imbalanced Nutrition: Less than Body Requirements, related to anorexia
– Desired outcome: The patient maintains adequate nutrition.
• Nonadherence to Therapeutic Regimen related to lack of motivation, poor self-image, or negative effects of prescribed drug
– Desired outcome: The patient adheres to drug regimen.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Phentermine: Planning and InterventionsPhentermine: Planning and Interventions
• Maximizing therapeutic effects
– Take daily.
– Exercise and low-calorie diet are important.
• Minimizing adverse effects
– Refrain from using drugs that may induce serotonin syndrome or elevate the blood pressure.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Phentermine: Teaching, Assessment, and EvaluationsPhentermine: Teaching, Assessment, and Evaluations
• Patient and family education
– Medication is only one component of weight loss.
– Discuss adverse effects and not taking with other OTC medication.
• Ongoing assessment and evaluation
– Calculate BMI at each follow-up visit.
– Evaluating the patient routinely is important for assessing progress.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
QuestionQuestion
• The cornerstone of weight loss is
– A. Drug therapy
– B. Exercise
– C. Healthy eating
– D. Both A and B
– E. All of the above
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
AnswerAnswer
• E. All of the above
• Rationale: Weight loss is a complex process that is multifactorial. Diet, exercise, and drug therapy are all a part of the process.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Respiratory Stimulants Respiratory Stimulants
• Respiratory stimulants are used to manage postsurgical respiratory depression and apnea in preterm neonates.
• Prototype drug: caffeine
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Caffeine: Core Drug Knowledge Caffeine: Core Drug Knowledge
• Pharmacotherapeutics
– Managing neonatal apnea, asthma, drowsiness, and fatigue
• Pharmacokinetics
– Administered: oral or IV. Distribution: rapidly throughout the body; crosses the placenta and blood–brain barrier
• Pharmacodynamics
– Direct stimulant at all levels of the CNS, which also stimulates the cardiovascular system
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Caffeine: Core Drug Knowledge (cont.)Caffeine: Core Drug Knowledge (cont.)
• Contraindications and precautions
– Anxiety disorders, panic disorder, or insomnia
• Adverse effects
– Tremor, sinus tachycardia, heightened attentiveness, diarrhea, excitement, irritability, and insomnia
• Drug interactions
– Oral contraceptives, psychostimulants, sympathomimetic agents, fluoroquinolone antibiotics, lithium, and MAOIs
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Caffeine: Core Patient Variables Caffeine: Core Patient Variables
• Health status
– Assess for contraindications to drug therapy.
• Life span and gender
– Pregnancy Category C drug
• Lifestyle, diet, and habits
– Limit intake of food and beverages that contain caffeine.
• Environment
– Administration of IV form to neonates needs to be done in an environment where the neonate can be monitored closely.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Caffeine: Nursing Diagnoses and Outcomes Caffeine: Nursing Diagnoses and Outcomes
• Disturbed Sleep Pattern related to insomnia
– Desired outcome: The patient will maintain adequate sleep and rest cycles.
• Anxiety related to stimulatory effects of caffeine
– Desired outcome: The patient will remain calm throughout therapy.
• Deficient Fluid Volume related to diuretic effect of caffeine and potential diarrhea
– Desired outcome: The patient will remain well hydrated.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Caffeine: Planning and InterventionsCaffeine: Planning and Interventions
• Maximizing therapeutic effects
– Take medication as directed.
– Do not crush extended-release form of medication.
• Minimizing adverse effects
– Adhere to the contraindications and precautions for caffeine therapy.
– Limit ingestion of caffeine from food and beverage sources.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
Caffeine: Teaching, Assessment, and EvaluationsCaffeine: Teaching, Assessment, and Evaluations
• Patient and family education
– Convey to the patient that caffeine is a drug and as such may create serious adverse effects
– Discuss adverse effects of the drug.
• Ongoing assessment and evaluation
– When used for respiratory depression or neonatal apnea, monitor the patient’s vital signs carefully.
– When administering for migraine headaches, monitor for potential adverse effects.
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
QuestionQuestion
• What is the effect of giving caffeine to a patient with panic disorder?
– A. Improvement of symptoms
– B. Exacerbation of symptoms
– C. No effect on symptoms at all
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
AnswerAnswer
• B. Exacerbation of symptoms
• Rationale: Caffeine will cause exacerbation of panic disorder symptoms due to CNS stimulation.