Topic+5
Topic 5: Objectives and Overview
5.1 CNS and PNS Drug Assessment: Discuss the mechanism of action, indications for use, and major adverse effects of selected drugs that affect the central nervous system (CNS) and peripheral nervous system (PNS).
5.2 Therapy Interactions: Discuss interactions of alternative and complementary therapies with medications that affect the CNS and PNS.
5.3 Influencing Factors: Identify client-related factors that influence the effects of drugs affecting the CNS and PNS.
5.4 Nursing Process Application: Use the nursing process to determine safe care for a client receiving medications that affect the CNS and PNS.
Methylphenidate (Ritalin/Concerta)
Classification: Amphetamine-like drug - CNS Stimulant.
Uses: * Attention-deficit hyperactivity disorder (ADHD). * Narcolepsy. * Reversal of respiratory depression.
Mode of Action (MOA): * Inhibits the re-uptake of dopamine and norepinephrine. * Results in CNS stimulation and augmentation of serotonin action. * Increases sympathomimetic activity.
Contraindications: * Monoamine Oxidase Inhibitor (MAOI) therapy. * Hereditary fructose intolerance.
Cautions: * Glaucoma, dysrhythmias, peripheral vascular disease, psychosis, various mental health conditions, hyperthyroidism, hypertension, cardiovascular disease, seizures, gastrointestinal (GI) obstruction, Tourette’s syndrome, older adults, pregnancy, and breast feeding.
Side Effects: * Anorexia, dry mouth, nausea/vomiting, dizziness, insomnia, irritability, restlessness, anxiety, confusion, depression, euphoria, hyperhidrosis, tremors, blurred vision, headache, abdominal pain, weight loss, constipation, diarrhea, and paresthesia.
Adverse Effects: * Tachycardia, hypertension, bradycardia, growth suppression, palpitations, seizures, psychosis, Tourette syndrome, Myocardial Infarction (MI), and stroke.
Life-Threatening Effects: * Blood dyscrasias, dysrhythmias, hepatotoxicity, and ocular hypertension.
Assessment (Recognize Cues): * Determine history of heart disease, hypertension, hyperthyroid, Parkinsonism, glaucoma, and mental health disorders. * Assess mental health status including mood, affect, and aggressiveness. * Evaluate height, weight, and growth, especially in children. * Assess vital signs and complete blood count (CBC), including differential white blood cells and platelets.
Nursing Diagnosis (Generate Hypotheses): * Sleep deprivation related to the adverse effect of insomnia.
Planning (Judge Hypotheses): * The patient will display less hyperactivity and increased attention span. * Blood Pressure (BP) and Heart Rate (HR) will remain within normal limits. * The patient will behave in a calm manner.
Nursing Interventions (Take Action): * Monitor vital signs and report irregularities. * Evaluate height, weight, and growth of children. * Observe for withdrawal symptoms. * Monitor for side effects.
Evaluate Outcomes: * Medication effectiveness and level of hyperactivity. * Presence of adverse effects. * Monitor weight, sleep patterns, and mental status. * Evaluate patient knowledge.
Client Teaching: * Take medication before meals. * Avoid alcohol consumption. * Encourage sugarless gum for dry mouth. * Monitor weight twice a week and report weight loss. * Avoid driving if experiencing tremors, nervousness, or increased heart rate. * Do not stop abruptly due to withdrawal risk. * Read labels of Over the Counter (OTC) medications for caffeine; avoid caffeine. * Encourage healthy foods to counteract anorexic effects. * Report side effects like tachycardia, palpitations, or signs of Tourette’s. * Nursing mothers should avoid this medication. * Direct families to seek counseling and inform the school. * Explain the risk of tolerance and potential for drug abuse.
Drug Interactions: * Increases stimulatory effects of sympathomimetics and psychostimulants. * Reduces effects of antihypertensives. * Increases effects of oral anticoagulants, barbiturates, anticonvulsants, and Tricyclic Anti-Depressants (TCAs). * Contraindicated with MAOIs (risk for hypertensive crisis). * Food Interactions: Caffeine, chocolate, tea, colas. * Herb Interactions: St. John’s Wort may decrease drug efficacy.
Sleep Disorders and Sedative-Hypnotics
Types and Stages of Sleep: * Rapid eye movement (REM). * Non-rapid eye movement (NREM).
Insomnia: * More common in female clients. * Treatment: Sedative-hypnotics.
Non-pharmacologic Management of Insomnia: * Arise at a specific hour in the morning. * Limit daytime naps. * Avoid caffeine, alcohol, and nicotine before bedtime. * Avoid heavy meals, large amounts of fluids, loud noise, and strenuous exercise before bedtime. * Engage in relaxing activities: warm bath, reading, quiet music, or warm milk before bedtime.
Sedative-Hypnotic Classifications: * Barbiturates. * Benzodiazepines. * Non-benzodiazepines.
General Side Effects of Sedative-Hypnotics: * Residual drowsiness (hangover), vivid dreams, nightmares, drug dependence, drug tolerance, excessive depression, respiratory depression, and hypersensitivity.
Alprazolam (Xanax)
Classification: Benzodiazepine.
Use: To treat anxiety and panic disorders.
Mode of Action: * Induces CNS depression by binding receptors in the limbic system and reticular formation. * Increases GABA (Gamma-Aminobutyric Acid) and GABA receptors. * Causes a shift of chloride ions leading to less excitability and stabilized neuronal membranes.
Contraindications: Respiratory depression, acute alcohol intoxication, psychotic reactions, and recent use of respiratory depressants.
Side Effects: Drowsiness, dizziness, amnesia, memory impairment, and GI effects.
Adverse Effects: Depression, tolerance, dependence, withdrawal, hypotension, tachycardia, and seizures.
Life-Threatening Effects: Hepatic failure and Stevens-Johnson syndrome.
Nursing Process for Alprazolam: * Assessment: Determine history of insomnia or anxiety; obtain drug history (including OTC); assess renal function. * Diagnosis: Sleep deprivation related to adverse effect of insomnia. * Planning: Patient will receive adequate sleep when taking benzodiazepines. * Interventions: Observe for adverse reactions (especially in older/debilitated clients); teach non-pharmacologic sleep methods; advise reporting adverse reactions; teach gradual withdrawal. * Antidote: Flumazenil. * Evaluation: Evaluate effectiveness in promoting sleep.
Zolpidem Tartrate (Ambien)
Classification: Sedative-hypnotic: Non-benzodiazepine.
Use: To treat insomnia.
Mode of Action: CNS depression and neurotransmitter inhibition.
Contraindications: Hypersensitivity to benzodiazepines, respiratory depression, and lactation.
Caution: Renal or liver dysfunction, mental depression, suicidal ideation, pregnancy, children, older adults, and debilitated individuals.
Side Effects: Hangover (residual sedation), memory impairment, nightmares, and binge eating.
Adverse Effects: Tolerance, psychological or physical dependence, withdrawal, sleep-related behaviors, hypotension, angioedema, depression, and suicidal ideation.
Life-Threatening Effects: Pulmonary edema and renal failure.
Nursing Process for Zolpidem: * Assessment: Baseline vital signs, liver enzymes, drug history, and nature of sleep disturbance. * Diagnosis: Sleep Deprivation related to anxiety; Fatigue related to insomnia. * Planning: Patient will remain asleep for to . * Interventions: Monitor vital signs for respiratory depression; use bed alarms for the elderly. * Client Teaching: Use non-pharmacological methods for sleep; avoid alcohol, antidepressants, antipsychotics, and narcotics; medication takes effect within to ; use caution when driving due to drowsiness.
Sedatives and Hypnotics for Older Adults
Determine underlying reasons for insomnia.
Utilize non-pharmacologic methods first.
Drug Choice: Short- to intermediate-acting benzodiazepines are considered safer.
Avoid: Long-acting benzodiazepines.
Frequency: Limit use to four times per week or less to avoid side effects.
Complementary and Alternative Therapies
Kava Kava: Should not be combined with CNS depressants as it may increase sedative effects.
Valerian: Used for insomnia; increases sedative effects when taken with alcohol or other CNS depressants.
Chamomile: Used for sleeplessness, anxiety, and stomach/intestinal ailments; side effects include allergic reactions and sedative effects.
Antiseizure Drugs and Epilepsy
Epilepsy (Seizure Disorder): Abnormal electric discharges from cerebral neurons. * Characteristics: Loss of consciousness, involuntary movements. * Causes: Unknown, or secondary to brain trauma, anoxia, infection, or stroke. Isolated seizures can be triggered by fever, electrolyte/acid-base imbalance, alcohol, or drugs.
Drug Actions: * Stabilize nerve cell membranes. * Suppress abnormal electric impulses in the cerebral cortex. * Mechanism: Suppress sodium influx, suppress calcium influx, or enhance GABA action.
Phenytoin (Dilantin)
Classification: Anticonvulsant: Hydantoin.
Uses: Prevention of tonic-clonic and partial seizures and status epilepticus.
Mode of Action: Reduces motor cortex activity by altering ion transport.
Contraindications: Pregnancy (teratogenic), hypersensitivity, heart block, and bradycardia.
Caution: Hyponatremia, hypotension, hypoglycemia, suicidal ideation, thyroid disease, alcoholism, Diabetes Mellitus (DM), renal/hepatic impairment, and Asian culture.
Side Effects: Gingival hyperplasia, nausea/vomiting, fatigue, headache, drowsiness, and dizziness.
Adverse Reactions: Leukopenia, hepatic impairment, depression, hyperglycemia, bradycardia, peripheral neuropathy, and Purple Glove Syndrome.
Life-Threatening Effects: Aplastic anemia, thrombocytopenia, Stevens-Johnson syndrome, hypotension, ventricular fibrillation, and suicidal ideation.
Nursing Process for Phenytoin: * Assessment: Current health history (drugs/herbs), renal, and hepatic function labs. * Diagnosis: Risk for injury; Risk for falls. * Planning: Diminished seizure frequency; adherence to therapy; minimal side effects. * Interventions: Monitor serum drug levels (Therapeutic range is ); warn patients on oral contraceptives to use backup methods; implement seizure precautions; monitor nutrition (anorexia/nausea side effects); advise against driving at therapy initiation.
Antiseizure Drugs and Pregnancy
Seizure episodes increase by in pregnant women with epilepsy.
Teratogenicity: Many antiseizure drugs cause birth defects.
Inhibition of Vitamin K: Contributes to infant hemorrhage after birth. Vitamin K may be given in the last days of pregnancy or to the infant immediately after birth.
Folate Loss: Antiseizure drugs increase the loss of folate (folic acid); daily supplements are required for pregnant females.
Drugs for Muscle Spasms
Goal: Reduce pain and increase range of motion.
Side Effects: Sedative effect.
Avoid Substandard Mixing: Do not take with barbiturates, narcotics, or alcohol.
Cyclobenzaprine (Flexeril): * Use: Short-term treatment of muscle spasms. * MOA: Relieves spasms via central action, possibly at the brainstem level. * Contraindications: Acute MI, bradycardia, heart block, cardiac arrhythmias, hypertension, heart failure, DM, hyperthyroidism, cerebral palsy, hypokalemia, paralytic ileus, and MAOI use. * Caution: Seizures, alcohol, CNS depressants, glaucoma, Benign Prostatic Hyperplasia (BPH), urinary retention, hepatic disease, and lactation. * Side Effects: Anticholinergic effects, arrhythmias, CNS effects, and unpleasant taste. * Adverse Reactions: Allergic reactions, angioedema, MI, seizures, and ileus.
Anxiety and Lorazepam (Ativan)
Types of Anxiety: * Primary: Not caused by medical conditions or drugs; managed with short-term anxiolytics. * Secondary: Related to drug use, medical, or psychiatric conditions; medications usually not indicated.
Lorazepam Classification: Anxiolytic: Benzodiazepine.
Use: Control anxiety, treat status epilepticus, sedation induction, and insomnia.
Mode of Action: Potentiates GABA effects by binding to benzodiazepine receptors and inhibiting GABA neurotransmission.
Side Effects: CNS effects, ataxia, amnesia, GI distress, and hallucinations.
Adverse Effects: Bradycardia, hypotension/hypertension, and seizures.
Life-Threatening Effects: Suicidal ideation, Neuroleptic Malignant Syndrome (NMS), and respiratory depression.
Discontinuation/Withdrawal: * Gradually decrease dose over several days. * Withdrawal symptoms develop in to and may last several weeks. * Symptoms: Tremor, agitation, nervousness, sweating, insomnia, anorexia, and muscle cramps.
Nursing Process for Benzodiazepines: * Assessment: Assess for suicidal ideation, anxiety history, and support system. * Diagnosis: Anxiety related to situational crisis; Noncompliance related to adverse effects. * Planning: Reduction of anxiety and stress. * Interventions: Observe for side effects (sedation), monitor vital signs, encourage family support, advise against driving, and warn against alcohol/CNS depressants.
Antidepressants
Depression Etiology: Genetic predisposition, social factors, and environmental factors.
Pathophysiology Theories: Decreased levels of monoamine neurotransmitters.
Signs/Symptoms: Depressed mood, despair, weight changes, loss of interest, fatigue, insomnia/hypersomnia, inability to concentrate, and suicidal thoughts.
Complementary Therapies for Depression: * Ginkgo biloba and St. John’s wort. * Discontinue herbal products before surgery. * Check with healthcare providers before use; do not combine with prescription antidepressants.
Antidepressant Drug Groups
Tricyclic Antidepressants (TCAs)
Action: Blocks reuptake of norepinephrine and serotonin; blocks histamine receptors (leads to sedation); blocks cholinergic receptors (anticholinergic effects).
Use: Major depression.
Interactions: Alcohol/CNS depressants (potentiate depression); MAOIs (toxic psychosis, cardiotoxicity); anti-thyroid drugs (increase dysrhythmias).
Side Effects/Adverse Reactions: Drowsiness, dizziness, blurred vision, dry mouth/eyes, GI distress, urinary retention, sexual dysfunction, weight gain, seizures, sleep-related behaviors, suicidal ideation, orthostatic hypotension, and dysrhythmias.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Action: Block reuptake of serotonin.
Uses: Major depression, anxiety disorders (OCD, panic, phobias, PTSD), prevention of migraines, and premenstrual tension syndrome.
Fluoxetine (Prozac): * Use: Depression, bipolar disorder, bulimia, OCD, panic disorder, premenstrual dysphoric disorder. * Contraindications: Hypersensitivity. * Caution: MI, MAOI use, dehydration, lactation, suicidal ideation, liver disease, osteoporosis, glaucoma, seizures, DM, malnourished state, anticoagulant therapy, and diarrhea. * Side Effects: CNS effects, memory impairment, tremors, dry mouth, blurred vision, GI effects, and erectile dysfunction. * Adverse Effects: Seizures, angioedema, hyponatremia, hypokalemia, hyperkalemia, hypoglycemia, dehydration, and bleeding osteoporosis. * Life-Threatening: Stevens-Johnson syndrome, hepatic dysfunction, and suicidal ideation. * Interactions: Grapefruit juice (toxicity); Alcohol/CNS depressants (respiratory depression); Aspirin/NSAIDs/Anticoagulants (bleeding risk); MAOIs/St. John's wort (Serotonin Syndrome).
Serotonin Norepinephrine Reuptake Inhibitors (SNRIs)
Use: Major depression, Generalized Anxiety Disorder (GAD), and social anxiety disorder.
Action: Increase serotonin and norepinephrine by blocking reuptake.
Side Effects: CNS effects, euphoria, amnesia, anticholinergic effects, weakness, diarrhea, and anorexia.
Adverse Effects: Tachycardia, seizure, HTN, and Serotonin Syndrome.
Life-Threatening: Suicidal ideation, NMS, renal failure, and Stevens-Johnson syndrome.
Interactions: Alcohol/CNS depressants; Anticoagulants/Aspirin; other SSRIs/SNRIs (risk for NMS); MAOIs (hypertensive crisis and death); St. John's wort (Serotonin Syndrome).
Monoamine Oxidase Inhibitors (MAOIs)
Action: Inactivates norepinephrine, dopamine, epinephrine, and serotonin.
Use: Depression not responding to TCAs or second-generation antidepressants.
Interactions: CNS stimulants (vasoconstrictors/cold meds with phenylephrine or pseudoephedrine) cause hypertensive crisis.
Side Effects: Agitation, restlessness, insomnia, anticholinergic effects, and orthostatic hypotension.
Tyramine Interaction: Hypertensive crisis occurs if taken with tyramine-rich foods. * Foods to Avoid: Aged cheese, cream, yogurt, coffee, chocolate, bananas, raisins, liver, pickled foods, sausage, soy sauce, yeast, beer, and red wine.
Nursing Process for Antidepressant Agents
Assessment: Baseline vitals and weight; history of depression, mental status, and suicidal ideation; drug/alcohol/herb history; baseline labs (creatinine, BUN, ALT/AST).
Diagnosis: Social isolation related to sadness; Risk for self-directed violence.
Planning: Depression will be decreased.
Interventions: * Observe for signs of depression, apathy