Introduction to Clinical Pharmacology Chapter 18 Central Nervous System Stimulants

CNS Stimulants: Action #1 Analeptics: Used for narcolepsy Increase depth of respirations- by stimulating chemoreceptors located in the carotid and upper aorta Caffeine: Cardiac, Respiratory, and CNS stimulation; dilation of coronary and peripheral blood vessels; constriction of cerebral blood vessels; skeletal muscle stimulation; diuretic

CNS Stimulants: Actions #2 Modafinil and armodafinil (treat narcolepsy): Exact mechanism of action is not known, but drug is thought to bind to dopamine, thereby reducing number of episodes Amphetamines: Elevate blood pressure; wakefulness; increase or decrease pulse rate; produce euphoric state Anorexiants: suppress appetite; ensure patient not taking any antidepressants

CNS 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 Reactions Neuromuscular reactions: Excessive CNS stimulation; headache; dizziness; apprehension; disorientation; hyperactivity Other: Nausea; vomiting; cough; dyspnea; urinary retention; tachycardia; palpitations

CNS Stimulants: Contraindications CNS stimulants contraindicated: In patients with known hypersensitivity; convulsive disorders (epilepsy); ventilation mechanism disorders such as COPD Nurse should not administer CNS stimulants to patients with: Cardiac problems; severe hypertension; hyperthyroidism; peptic ulcer Amphetamines: Contraindicated in glaucoma

CNS Stimulants: Precautions Use CNS stimulants with caution in: Respiratory illness Renal and/or hepatic impairment History of substance abuse Pregnant or lactating women

CNS 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: Assessment #1 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: Assessment #2 Preadministration assessment (cont.) 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: Assessment #3 Preadministration assessment (cont.) 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: Assessment #4 Ongoing assessment: Respiratory depression: After administering analeptic: monitor respiratory rate and respiration pattern until respirations return to normal Monitor level of consciousness, blood pressure, and pulse rate at 5- to 15-minute intervals or as ordered by primary health care provider

Nursing Process: Assessment #5 Ongoing assessment (cont.) Respiratory depression (cont.) Take blood sample for arterial blood gas analysis, to determine effectiveness of analeptic Observe adverse drug reaction; report occurrence immediately to primary health care provider

Nursing Process: Nursing Diagnosis and Planning Disturbed Sleep Pattern; Ineffective Breathing Pattern; Imbalanced Nutrition Expected outcomes: Depend on reason for administration Optimal response to therapy Support patient needs: manage adverse drug reactions Understanding: drug regimen

Nursing Process: Implementation #1 Promoting an optimal response to therapy: Amphetamines: used for short-term treatment of exogenous obesity Long-term use: causes addiction and abuse

Nursing Process: Implementation #2 Monitoring and managing patient needs taking amphetamines: Disturbed sleep patterns: CNS stimulant therapy: causes insomnia; anxiety, and confusion Avoid coffee, tea, cola drinks Vital signs: checked every 6 to 8 hours Adverse reactions: amphetamine use may require discontinuation of drug

Nursing Process: Implementation #3 Monitoring and managing patient needs (cont.) Ineffective breathing pattern: Respiratory depression: requires administration of respiratory stimulant Before administering drug: record rate, depth, character of respirations; ensure patent airway

Nursing Process: Implementation #4 Monitoring and managing patient needs (cont.) Ineffective breathing pattern (cont.) After administration: monitor respirations closely; record effects of therapy Respiratory depression: assess patient’s level of pain

Nursing Process: Implementation #5 Monitoring and managing patient needs (cont.) Ineffective breathing pattern (cont.) Use of analeptic drugs for respiratory stimulation: enhances breathing pattern; keep record of number of times periods of sleepiness occur during the day and bring information to doctor visits Doxapram: causes urinary retention; measure intake and output, notify primary health care provider if patient unable to void or bladder appears distended

Nursing Process: Implementation #6 Monitoring and managing patient needs (cont.) Imbalanced nutrition: less than bodily requirements Adverse reactions: use of CNS stimulants in child with ADHD decreases appetite Long-term treatment: CNS stimulants retard growth in children

Nursing Process: Implementation #7 Monitoring and managing patient needs (cont.) Imbalanced nutrition (cont.) Monitor weight, growth patterns in children on long-term treatment with CNS drugs Frequently check height, weight of child to monitor growth Primary health care provider may periodically interrupt therapy to monitor effectiveness of therapy

Nursing Process: Implementation #8 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 Instruct the client to administer the drug early in the day, avoid caffeine and other CNS stimulants, be active during the day, and not nap during the day to aid in sleep alteration caused by the use of a CNS stimulant.

Nursing Process: Implementation #9 Educating the patient and family (cont.) 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 Ensure that weight and growth are monitored and recorded on routine health visits

Nursing Process: Implementation #10 Educating the patient and family (cont.) Additional teaching points (cont.) Narcolepsy: Record number of times per day periods of sleepiness occur Amphetamines and anorexiants: Avoid coffee, tea, carbonated beverages containing caffeine

Nursing Process: Implementation #11 Educating the patient and family (cont.) Additional teaching points (cont.) Caffeine: Should not be used if heart palpitations, dizziness, or lightheadedness occurs

Nursing Process: Evaluation #1 Child’s behavior, school performance improve Weight loss is achieved Respiratory depression is reversed Fewer episodes of inappropriate sleep patterns are reported Adverse reactions are identified, reported, and managed

Nursing Process: Evaluation #2 Patient complies with prescribed drug regimen Patient and family demonstrate understanding of drug regimen Patient verbalizes importance of complying with prescribed therapeutic regimen

Question #1 Is the following statement true or false? CNS stimulants enhance neurotransmission and stimulate receptors in different parts of the brain.

Answer to Question #1 True CNS stimulants enhance neurotransmission and stimulate receptors in different parts of the brain. These drugs are used for ADHD, narcolepsy, respiratory depression, and weight loss. They should not be used to treat clinical depression.

Question #2 Is the following statement true or false? There is a low degree of addiction potential with CNS stimulant drugs due to depression of the brain’s pleasure centers with enhanced neurotransmission of dopamine.

Answer to Question #2 False There is a high degree of addiction potential with these drugs due to stimulation of the brain’s pleasure centers with enhanced neurotransmission of dopamine.

Question #3 Is the following statement true or false? When used routinely, administration of stimulants is offered in long-acting form or in the morning and at lunchtime to reduce the incidence of insomnia.

Answer to Question #3 True When used routinely, administration of stimulants is offered in long-acting form or in the morning and at lunchtime to reduce the incidence of insomnia.