CNS Stimulants PDF

CNS Stimulants ‹#›  CNS Stimulants Categories Amphetamines Analeptics Anorexiants Medically approved uses…limited to treatment of: Attention deficit/hyperactivity disorder (ADHD) Narcolepsy Reversal of respiratory distress...

CNS Stimulants ‹#›  CNS Stimulants Categories Amphetamines Analeptics Anorexiants Medically approved uses…limited to treatment of: Attention deficit/hyperactivity disorder (ADHD) Narcolepsy Reversal of respiratory distress ‹#› 3 Attention Deficit/Hyperactivity Disorder (ADHD) Pathophysiology Dysregulation of transmitters Serotonin, norepinephrine, dopamine Epidemiology Usually occurs in children before age 7 years More common in boys Characteristics Inattentiveness, inability to concentrate, restlessness, hyperactivity, inability to complete tasks, impulsivity ‹#› 4 Amphetamines Action Stimulate release of norepinephrine and dopamine Side effects/adverse reactions Tachycardia, palpitations, hypertension Sleeplessness, restlessness Irritability Anorexia, dry mouth, weight loss, diarrhea, constipation Impotence ‹#› 6 Amphetamine-Like Drugs Methylphenidate and dexmethylphenidate Uses Increase a child’s attention span and cognitive performance (e.g., memory, reading); decrease impulsiveness, hyperactivity, and restlessness ‹#› 7  Methylphenidate Action Modulates serotonergic pathways by affecting changes in dopamine transport Uses: ADHD, fatigue, narcolepsy Interactions Caffeine may increase effects. Decreased effects of decongestants, antihypertensives, barbiturates May alter insulin effects ‹#› 9  Methylphenidate (Cont.) Side effects/adverse reactions Tachycardia, palpitations, dizziness, hypertension Sleeplessness, restlessness, nervousness, tremors, irritability Increased hyperactivity Anorexia, dry mouth, vomiting, diarrhea, weight loss Thrombocytopenia  Methylphenidate (Cont.) Nursing Considerations Give before breakfast and lunch. Report irregular heartbeat. Record height, weight, and growth of children. Avoid alcohol, caffeine. Use sugarless gum to relieve dry mouth. Do not stop abruptly; taper off to avoid withdrawal symptoms. Counseling should also be used. Narcolepsy Characteristics Recurrent attacks of drowsiness and sleep during daytime Unable to control sleep Falling asleep while Driving Talking Eating Standing ‹#› 5 Amphetamine-Like Drugs for Narcolepsy ‹#› 8  Respiratory Stimulants- Analeptics Caffeine Theophylline Use Stimulate respiration in newborns Side effects Restlessness, tremors, twitching, palpitations, insomnia Diuresis, tinnitus, nausea, diarrhea Psychological dependence ‹#› Other Respiratory Stimulants Doxapram Uses Respiratory depression caused by overdose, pre- and postanesthetic respiratory depression, and chronic obstructive pulmonary disease (COPD) Onset of action 20 to 40 seconds, peak within 2 minutes Side effects Hypertension, tachycardia, trembling, convulsions ‹#› 14 Central Nervous System Depressants  Sleep Disorders Insomnia More common in female patients Treatment: sedative-hypnotics Nonpharmacologic management No daytime naps Warm fluids to drink Caffeine avoided 6 hr before bedtime Heavy meals and exercise avoided before bedtime Warm bath, reading, listening to music 3  Sedative-Hypnotics Sedatives Produce mildest form of CNS depression Sedative-hypnotics Barbiturates Benzodiazepines Nonbenzodiazepines OTC Sominex, Tylenol PM Diphenhydramine 4  Sedative-Hypnotics (Cont.) General side effects Residual drowsiness (hangover) Drug dependence Drug tolerance Excessive depression Respiratory depression Withdrawal symptoms 5  Barbiturates Long-acting Intermediate-acting Short-acting Restricted to short-term use (2 weeks or less) because of side effects, including drug tolerance Interactions: alcohol, opioids, other sedative- hypnotics 6 Barbiturates and Alcohol Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc. ‹#›  Benzodiazepines Benzodiazepines as hypnotics Flurazepam Alprazolam Temazepam Triazolam Estazolam For anxiety–Lorazepam and diazepam 7  Benzodiazepines Benzodiazepines as hypnotics Action Interacts with neurotransmitter GABA to reduce neuron excitability Use Reduce anxiety, treat insomnia 8  Sedative Hypnotic - Nonbenzo Zolpidem Action Neurotransmitter inhibition Its duration of action is 6 to 8 hours with a short half-life of 2 to 4.5 hours. Use Treat short-term (less than 10 days) insomnia  Sedatives and Hypnotics for Older Adults Identify cause. Use nonpharmacologic methods first. Use short- to intermediate-acting benzodiazepines such as estazolam, temazepam, and triazolam. Avoid benzodiazepines such as flurazepam, quazepam, and diazepam. 11 Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc. ‹#›  Sedative-Hypnotics Drug interactions Alcohol, CNS depressants Nursing Considerations First use nonpharmacologic methods. Be attentive to safety. Avoid alcohol, other CNS depressants. Take 15 to 45 minutes before bedtime. Report hangover effect. Monitor BP, RR. Taper gradually. Avoid driving.  Melotonin Agonists Ramelteon Rozerem website First FDA-approved hypnotic not classified as a controlled substance Selectively targets melatonin receptors to regulate circadian rhythm in the treatment of insomnia Not been shown to decrease REM sleep Adverse effects: drowsiness, dizziness, fatigue, headache, nausea, and suicidal ideation Also used as an antianxiety drug Anti-seizure Drugs Epilepsy Seizure disorder Abnormal electric discharges from cerebral neurons Characteristics Loss of consciousness Convulsive movements Cause Unknown Secondary to trauma, anoxia, infection, stroke Isolated seizures due to fever, electrolyte, or acid-base imbalance International Classification of Seizures Generalized Tonic-clonic (grand mal) Most common Generalized alternating muscle spasms and jerkiness Absence (petit mal) Brief loss of consciousness (10 seconds or less) Usually occurs in children Anticonvulsants/Antiepileptic Drugs (AEDs) Action: Suppress abnormal neuron firing Suppress sodium influx Phenytoin, fosphenytoin, carbamazepine, oxcarbazepine, valproic acid, topiramate, zonisamide, lamotrigine Suppress calcium influx Valproic acid, ethosuximide Enhance action of GABA Barbiturates, benzodiazepines, tiagabine Promote GABA release Gabapentin  Hydantoins Phenytoin Contraindications Pregnancy (teratogenic) Therapeutic serum level 10 to 20 mcg/mL Side effect/adverse reactions Gingival hyperplasia, nystagmus Headache, diplopia, dizziness, slurred speech, decreased coordination, alopecia Thrombocytopenia, Stevens-Johnson syndrome Constipation Hydantoins (Cont.) Phenytoin Drug interactions Increased effects with cimetidine (Tagamet), INH, sulfonamides Decreased effects with folic acid, antacids, calcium, sucralfate, antineoplastics, antipsychotics, primrose, ginkgo Decreased effects of anticoagulants, oral contraceptives, antihistamines, dopamine, theophylline  Hydantoins (Cont.) Nursing Considerations Shake suspension well for 5 minutes. Monitor serum drug levels. Safety: Protect from environmental hazards, driving. Warn female patients taking oral contraceptives to use additional contraception. Warn patient to avoid certain herbs, alcohol, and other CNS depressants. Warn patient not to discontinue abruptly. Patient will need frequent oral hygiene and dental check-ups. Diabetics must monitor glucose level. Tell patient to take drug at same time every day. Warn of harmless pinkish red or brown urine. Teach patient to report sore throat, bruising, nosebleeds. Encourage patient to wear medical-alert identification. Barbiturates Phenobarbital Shake suspension well for 5 minutes. Treats partial seizures, grand mal seizures, acute episodes of status epilepticus seizures, meningitis, toxic reactions, and eclampsia Therapeutic serum range of phenobarbital is 20 to 40 mcg/mL. Risks–sedation and patient tolerance to the drug Discontinuance of phenobarbital should be gradual to avoid recurrence of seizures. Succinimide Ethosuximide Therapeutic serum range of ethosuximide is 40 to 100 mcg/mL. Adverse effects include blood dyscrasias, renal and liver impairment, and systemic lupus erythematosus. Benzodiazepines Clonazepam Effective in controlling petit mal (absence) seizures Tolerance may occur 6 months after drug therapy starts Clorazepate dipotassium Administered in adjunctive therapy for treating partial seizures Lorazepam Drug of choice for treating acute status epilepticus Must be administered IV to achieve the desired response Carbamazepine (Tegretol) Effective in treating refractory seizure disorders that have not responded to other anticonvulsant therapies Used to control grand mal and partial seizures and a combination of these seizures Also used for psychiatric disorders (e.g., bipolar disorder), trigeminal neuralgia (as an analgesic), and alcohol withdrawal Therapeutic serum range of carbamazepine is 5 to 12 mcg/mL. An interaction may occur when grapefruit juice is taken with carbamazepine, causing possible toxicity. Valproate Valproic acid: Used to treat petit mal, grand mal, and mixed types of seizures Safety and efficacy of this drug has not been established for children younger than 2 years of age. Caution in patients with liver disorders, because hepatotoxicity is one of the possible adverse reactions. Liver enzymes should be monitored. Therapeutic serum range is 50 to 100 mcg/mL. Levitiracetam Indicated as adjunctive treatment in partial onset seizures in patients with epilepsy. Exact MOA unknown Monitor levels in pregnancy as they can gradually decrease. Can be used in patients as young as 1 month. Should not be discontinued abruptly Most common adverse effect is somnolence and irritability Serious dematologic reactions (Stevens-Johnson, toxic epidermal necrolysis) have been reported. Avoid driving until effects are known. Monitor for suicidal ideation. ‹#›  Levitiracetam Medication Grid Class/Subclass Prototype/Generic Administration Considerations Therapeutic Effects Adverse/Side Effects Behavioral/mood changes (psychotic symptoms, suicidal ideation, irritability, and Taper dose; do not stop abruptly aggressive behavior)Anaphylaxis or seizures may occurMonitor or angioedema Anticonvulsant levetiracetam Decrease seizure activity plasma levels for pregnant women Somnolence, fatigue, and Use cautiously if renal impairment irritability Serious skin conditions Coordination difficulties Hematopoietic abnormalities Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc. ‹#›  Gabapentin Indicated for adjunct treatment of partial onset seizures, but mostly used for neuropathic pain MOA unknown, but it is structurally related to GABA Class/Subclass Prototype/Generic Administration Considerations Therapeutic Effects Adverse/Side Effects Administer first dose at bedtime to decrease dizziness and Increased suicidal drowsinessMonitor for worsening ideationImmediately report fever, Decreased neuropathic pain or Anticonvulsant gabapentin depression, suicidal thoughts or rash, and/or lymphadenopathy seizures behavior, and/or any unusual CNS depression: dizziness, changes in mood or behavior somnolence, and ataxia Taper dose; do not stop abruptly ‹#› Anticonvulsants and Pregnancy Seizure episodes increase 25% in women with epilepsy who are pregnant. Hypoxia that may occur during seizures places both the pregnant patient and the fetus at risk. Many anticonvulsant drugs have teratogenic properties that increase the risk for fetal malformations. Fetal hydantoin syndrome Anticonvulsant drugs tend to act as inhibitors of vitamin K, contributing to hemorrhage in infants shortly after birth. Anticonvulsants also increase the loss of folate (folic acid) in pregnant patients. Anticonvulsants and Febrile Seizures Seizures associated with fever usually occur in children between the ages of 3 months and 5 years. Epilepsy develops in approximately 2.5% of children who have had one or more febrile seizures. Prophylactic anticonvulsant treatment such as phenobarbital or diazepam may be indicated for high-risk patients. Valproic acid should not be given to children younger than 2 years because of its possible hepatotoxicity. Anticonvulsants and Status Epilepticus Continuous seizure state Medical emergency Lorazepam administered IV IV administration of phenytoin For continued (refractory) seizures: Midazolam or propofol Drugs for Parkinson’s Disease Parkinsonism Pathophysiology Chronic neurologic disorder Imbalance of the neurotransmitters dopamine (DA) and acetylcholine (ACh) Marked by degeneration of neurons of the extrapyramidal motor tract Reason for the degeneration of neurons is unknown. Parkinsonism (Cont.) Characteristics Tremors of head and neck Rigidity (increased muscle tone) Bradykinesia (slow movement) Postural changes Head and chest thrown forward Shuffling walk Lack of facial expression Pill-rolling motion of hands Parkinsonism (Cont.) Treatment regimen Anticholinergics Block cholinergic receptors Dopaminergics Convert to dopamine Dopamine agonists Stimulate dopamine receptors MAO-B inhibitors Inhibit MAO-B enzyme that interferes with dopamine COMT inhibitors Inhibit COMT enzyme that inactivates dopamine Antiparkinsonism Drugs Anticholinergics Parasympatholytic–inhibit the release of acetylcholine Benztropine Trihexyphenidyl HCl Action: inhibit release of acetylcholine Decreases involuntary movement, tremors, muscle rigidity Minimal effect on bradykinesia Used to treat drug-induced parkinsonism, or pseudoparkinsonism  Antiparkinsonism Drugs (Cont.) Anticholinergics Nursing Interventions Monitor vital signs. Monitor urine output for early detection of urinary retention. Increase fluid intake, fiber, and exercise to avoid constipation. Observe for involuntary movements. Advise patient to avoid alcohol, cigarettes, caffeine, and aspirin to decrease gastric acidity. Encourage patient to relieve dry mouth with ice chips, hard candy, or sugarless chewing gum. Suggest use of sunglasses for photophobia. Antiparkinsonism Drugs (Cont.) Dopaminergics Carbidopa-levodopa (Sinemet) Action: converted to dopamine Increases mobility Side effects Fatigue, insomnia Dry mouth Blurred vision Orthostatic hypotension, palpitations, dysrhythmias Urinary retention Nausea, vomiting Dyskinesia, psychosis, severe depression  Dopaminergics (Cont.) Carbidopa-levodopa Function Advantages a. When levodopa is used alone, only 1% reaches the brain because 99% converts to dopamine while in the peripheral nervous system. b. By combining carbidopa with levodopa, carbidopa can inhibit the enzyme decarboxylase in the periphery, thereby allowing more levodopa to reach the brain.  Dopaminergics Carbidopa-levodopa Drug interactions Decrease levodopa effect with: Anticholinergics Phenytoin Tricyclic antidepressants MAO inhibitors Benzodiazepines Phenothiazines Vitamin B₆ Dopamine Agonists Amantadine Also antiviral drug for influenza A Action Stimulates dopamine receptors Taken alone or in combination with levodopa or anticholinergic Use Early treatment of parkinsonism as drug tolerance develops Improvement of symptoms  Antiparkinsonism Drugs (Cont.) Nursing Considerations Monitor for orthostatic hypotension. Administer drug with low-protein foods. Avoid vitamin B₆, alcohol, other depressants. Do not abruptly discontinue. Warn of harmless brown discoloration of urine and sweat. Assess for suicidal tendencies. Assess symptom status and “on-off” phenomenon. Monitor blood cell counts, liver and kidney function. Copyright © 2015, 2012, 2009, 2006, 2003, 2000, 1997, 1993 by Saunders, an imprint of Elsevier Inc. ‹#›