Chapters 15-17

Chapters 15-17Drugs Affecting the Central Nervous System

CHAPTER 15

Antiepileptic Drugs

Learning Objectives

1. Briefly describe the pathophysiology of epilepsy.2. Discuss the rationale for the use of the various classes of antiepileptic drugs (AEDs) administered for management of the different forms of epilepsy.3. Identify the various drugs in each of the following drug classes: iminostilbenes, benzodiazepines, barbiturates, hydantoins, and miscellaneous drugs.4. Identify the mechanisms of action, indications, cautions, contraindications, dosages, routes of administration, adverse effects, toxic effects, related therapeutic blood levels, and drug interactions for the drugs in each AED class.5. Develop a nursing care plan, including patient education, based on the nursing process for patients receiving AEDs.

EpilepsySeizureBrief episode of abnormal electrical activity in nerve cells of the brainConvulsionInvoluntary spasmodic contractions of any or all voluntary muscles throughout the body, including skeletal and facial musclesEpilepsyChronic, recurrent pattern of seizures

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Epilepsy (contd)Primary (idiopathic)Cause cannot be determinedMore than 50% of epilepsy casesSecondary (symptomatic)Distinct cause is identifiedTrauma, infection, cerebrovascular disorder

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Classification of EpilepsyPartial-onset seizuresSimple (formerly known as petit mal seizures)Complex Secondary generalized tonic-clonic Generalized-onset seizuresFormerly known as grand mal seizuresUnclassified seizuresStatus epilepticus

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Antiepileptic Drugs (AEDs)Also known as anticonvulsantsGoals of therapyTo control or prevent seizures while maintaining a reasonable quality of lifeTo minimize adverse effects and drug-induced toxicityAED therapy is usually lifelongCombination of drugs may be used

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Antiepileptic Drugs (contd)Single-drug therapy started before multiple-drug therapy is triedSerum drug concentrations must be measuredTherapeutic drug monitoringPatients who are seizure free for 1 to 2 years may be able to discontinue antiepileptic therapy

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Mechanism of ActionAED therapy must:Prevent generation and spread of excessive electrical discharge from abnormally functioning nerve cellsProtect surrounding normal cells

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Mechanism of Action (contd)Exact mechanism of action is not knownAEDs are thought to alter movement of sodium, potassium, and calcium ions across nerve cells in the brainReduce nerves ability to be stimulatedSuppress transmission of impulses from one nerve to the nextDecrease speed of nerve impulse conduction within a neuron

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Mechanism of Action (contd)Overall effectNeurons are stabilizedNeuron hyperexcitability is decreasedSpread of excessive nerve impulses is decreased

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Antiepileptic Drugs:IndicationsPrevention or control of seizure activityLong-term maintenance therapy for chronic, recurring seizuresAcute treatment of convulsions and status epilepticusOther uses

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Antiepileptic Drugs

Numerous adverse effectsvary per drugAdverse effects often necessitate a change in medicationBlack box warning as of 2008Suicidal thoughts and behaviorLong-term therapy with phenytoin may cause gingival hyperplasia, acne, hirsutism, and Dilantin facies

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Antiepileptic Drugs (contd)Barbiturates, such as phenobarbital (Luminal)carbamazepine (Tegretol)valproic acid (Depakene)felbamate (Felbatol)Hydantoins, such as phenytoin (Dilantin) and fosphenytoin

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Antiepileptic Drugs (contd)Succinimides, such as ethosuximide (Zarontin)Benzodiazepines (clonazepam and clorazepate)gabapentin (Neurontin)lamotrigine (Lamictal)pregabalin (Lyrica)levetiracetam (Keppra)topiramate (Topamax)tiagabine (Gabitril)Others

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Nursing ImplicationsAssessmentHealth history, including current medicationsDrug allergiesLiver function studies, CBCBaseline vital signs

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Nursing Implications (contd)Oral drugsTake regularly, same time each dayTake with meals to reduce GI upsetDo not crush, chew, or open extended-release formsIf patient is NPO for a procedure, contact physician regarding AED dosage

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Nursing Implications (contd)Intravenous formsFollow manufacturers recommendations for IV deliveryusually given slowlyMonitor vital signs during administrationAvoid extravasation of fluidsUse only normal saline with IV phenytoin

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Nursing Implications (contd) Teach patients to keep a journal to monitor:Response to AEDSeizure occurrence and descriptionsAdverse effectsInstruct patients to wear a medical alert tag or IDAEDs should not be discontinued abruptlyDriving may be impaired until drug levels stabilize

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Nursing Implications (contd) Teach patients that therapy is long term and possibly lifelong (not a cure)Monitor for therapeutic effectsDecreased or absent seizure activityMonitor for adverse effectsMental status changes, mood changes, changes in level of consciousness or sensoriumEye problems, visual disordersSore throat, fever (blood dyscrasias may occur with hydantoins)Many others

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CHAPTER 16

Antiparkinsonian Drugs

Learning Objectives

1. Briefly discuss the impact of acetylcholine and dopamine on the brain.2. Describe the pathophysiology of Parkinsons disease.3. Identify the different classes of medications used to manage Parkinsons disease, including first- and second-line drugs used in therapy.4. Discuss the mechanisms of action, dosages, indications, routes of administration, contraindications, cautions, drug interactions, adverse effects, and toxic effects of antiparkinsonian drugs.5. Develop a nursing care plan that includes all phases of the nursing process for patients taking antiparkinsonian drugs.

Parkinsons Disease (PD)Chronic, progressive, degenerative disorderAffects dopamine-producing neurons in the brainCaused by an imbalance of two neurotransmittersDopamineAcetylcholine (ACh)

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Parkinsons Disease (contd)Symptoms occur when about 80% of the dopamine stored in the substantia nigra of the basal ganglia is depletedSymptoms can be partially controlled as long as there are functioning nerve terminals that can take up dopamine

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Parkinsons Disease (contd)Classic symptoms include:Akinesia BradykinesiaRigidityTremorPostural instability

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Parkinsons Disease (contd)A progressive conditionRapid swings in response to levodopa occur (on-off phenomenon)PD worsens when too little dopamine is presentDyskinesia occurs when too much dopamine is present

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DyskinesiaDifficulty in performing voluntary movementsTwo common typesChorea: irregular, spasmodic, involuntary movements of the limbs or facial musclesDystonia: abnormal muscle tone leading to impaired or abnormal movements

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Levodopa TherapyLevodopa is a precursor of dopamineBlood-brain barrier does not allow exogenously supplied dopamine to enter, but does allow levodopa

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Levodopa Therapy (contd)Levodopa is taken up by the dopaminergic terminal, converted into dopamine, and then released as neededAs a result, neurotransmitter imbalance is controlled in patients with early PD who still have functioning nerve terminals

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Levodopa Therapy (contd)As PD progresses, it becomes more difficult to control it with levodopaUltimately, levodopa no longer controls the PD, and patient is seriously debilitatedThis generally occurs between 5 and 10 years after the start of levodopa therapy

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Drug Therapy for PDAimed at increasing levels of dopamine as long as there are functioning nerve terminals remainingAntagonizes or blocks the effects of AChSlows the progression of the disease

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Drug Therapy for PD (contd)Indirect-acting dopamine-receptor agonistsMAOB inhibitors: selegiline, rasagilineCOMT inhibitors: entacapone, tolcaponePresynaptic dopamine release enhancer: amantadine

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Drug Therapy for PD (contd)Anticholinergic drugsBenztropine, othersAntihistaminesDiphenhydramineNondopamine-receptor agonists Ergot: bromocriptineNonergot: pramipexole, ropinirole, apomorphineDopamine replacement drugsCarbidopa, carbidopa-levodopa

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Selective MAOI Therapy: SelegilineMAOIs break down catecholamines in the CNS, primarily in the brainSelegiline is a selective MAOB inhibitorCauses an increase in levels of dopaminergic stimulation in the CNS

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Selective MAOI Therapy: Selegiline (contd)Selegiline is a newer, potent, irreversible MAOI that selectively inhibits MAOBDoes not elicit the cheese effect of the nonselective MAOIs used to treat depression (if 10 mg or less is used)

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Selective MAOI Therapy: Selegiline (contd)Used in combination with levodopa or levodopa-carbidopaUsed as an adjunct when a patients response to levodopa is fluctuatingAllows the dose of levodopa to be decreasedDelays development of unresponsiveness to levodopa therapy

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Selective MAOI Therapy: Selegiline (contd)Improves functional abilityDecreases severity of symptomsOnly 50% to 60% of patients show a positive response to therapyProphylactic selegiline may delay the development of serious debilitating PD for 9 to 18 yearsRasagiline approved in 2008 with similar action to selegiline

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Selective MAOI Therapy: Selegiline (contd)Adverse effects are usually mildNausea, lightheadedness, dizziness, abdominal pain, insomnia, confusion, dry mouthDoses higher than 10 mg/day may cause more severe adverse effects, such as hypertensive crisis

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Presynaptic Dopamine Release EnhancerAmantadine (Symmetrel)Indirect-actingCauses release of dopamine from storage sites at the end of nerve cells that are still intactBlocks reuptake of dopamine into the nerve endings, allowing more to accumulate both centrally and peripherallyDoes not stimulate dopamine receptors directly

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Presynaptic Dopamine Release Enhancer (contd)Amantadine (Symmetrel)Used early in the course of the diseaseUsually effective for only 6 to 12 monthsAlso used as an antiviral for influenza virus infection

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COMT InhibitorsIndirect-actingTolcapone (Tasmar) and entacapone (Comtan)Inhibit COMT, the enzyme responsible for the breakdown of levodopa, the dopamine precursorProlong the duration of action of levodopa; reduce wearing off phenomenon

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COMT Inhibitors (contd)Tolcapone (Tasmar)Has caused severe liver failureRequires monitoring of liver enzymesNot used unless other drugs do not work

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Direct-Acting Dopamine Receptor AgonistsNondopamine dopamine receptor agonists (NDDRAs)Ergot derivatives (bromocriptine and pergolide)Nonergot drugs (pramipexole, ropinirole, apomorphine)Dopamine replacement drugs Levodopa, carbidopa, carbidopa-levodopa (Sinemet)

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Direct-Acting Dopamine Receptor Agonists (contd)Nondopamine dopamine receptor agonists (NDDRAs)Ropinirole (Requip)Newer, nonergot NDDRAUsed for PD and restless leg syndromeApomorphine (Apokyn)Newer, nonergot dopamine agonistSubcutaneous injection

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Comp (CN) - AU: OK as edited?Direct-Acting Dopamine Receptor Agonists (contd)Direct-actingBromocriptine (Parlodel)Directly stimulate dopamine receptorsActivate dopamine receptors and stimulate production of more dopaminePergolide (Permax) is another direct-acting drug with a different mechanism of action

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Dopamine Replacement DrugsReplacement drugs (presynaptic)Work presynaptically to increase brain levels of dopamineLevodopa is able to cross the blood-brain barrier, and then it is converted to dopamineHowever, large doses of levodopa needed to get dopamine to the brain also cause adverse effects

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Dopamine Replacement Drugs (contd)Replacement drugsCarbidopa is given with levodopaCarbidopa does not cross the blood-brain barrier and prevents levodopa breakdown in the peripheryAs a result, more levodopa crosses the blood-brain barrier, where it can be convertedto dopamine

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Anticholinergic TherapyAnticholinergics block the effects of AChUsed to treat muscle tremors and muscle rigidity associated with PDThese two symptoms are caused by excessive cholinergic activityDoes not relieve bradykinesia (extremely slow movements)

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Anticholinergic Therapy (contd)ACh accumulates because of the imbalance of dopamineAs a result, overstimulation of the cholinergic excitatory pathways occursMuscle tremors and muscle rigidityCogwheel rigidityPill-rolling movement of fingers and head bobbing while at rest

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Anticholinergic Therapy (contd)benztropine mesylate (Cogentin)Also used to treat extrapyramidal symptoms caused by use of antipsychotic drugsTrihexyphenidyl (generic only)Antihistamines also have anticholinergic propertiesdiphenhydramine (Benadryl)

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Anticholinergic Therapy:IndicationsUsed in the treatment of PD to cause smooth muscle to relax, resulting in reduced muscle rigidity and akinesiaAlso used to treat drug-induced extrapyramidal reactions to certain antipsychotic drugs

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Anticholinergic Therapy:Adverse EffectsDrowsiness, confusion, disorientationConstipation, nausea, vomitingUrinary retention, pain on urinationBlurred vision, dilated pupils, photophobia, dry skinDecreased salivation, dry mouth

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Nursing ImplicationsPerform a thorough assessment, nursing history, and medication historyInclude questions about the patients:CNSGI and GU tractsPsychologic and emotional status

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Nursing Implications (contd)Assess for signs and symptoms of PDMasklike expressionSpeech problemsDysphagiaRigidity of arms, legs, and neckAssess for conditions that may be contraindications

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Nursing Implications (contd)Administer drugs as directed by manufacturerProvide patient education regarding PD and the medication therapyInform patient not to take other medications with PD drugs unless he or she checks with physician

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Nursing Implications (contd)When starting dopaminergic drugs, assist patient with walking because dizziness may occurAdminister oral doses to minimize GI upsetEncourage patient to force fluids to at least 2000 mL/day (unless contraindicated)Taking levodopa with MAOIs may result in hypertensive crisis

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Nursing Implications (contd)Patient should be taught not to discontinue antiparkinsonian drugs suddenlyTeach patient about what therapeutic and adverse effects to expect with antiparkinsonian drug therapy

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Nursing Implications (contd)Levodopa preparations may darken the patients urine and sweatTherapeutic effects of COMT inhibitors may be noticed within a few days; it may take weeks with other drugs

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Nursing Implications (contd)Monitor for response to drug therapyImproved sense of well-being and mental statusIncreased appetiteIncreased ability to perform ADLs, to concentrate, and to think clearlyLess intense parkinsonian manifestations, such as less tremor, shuffling gait, muscle rigidity, and involuntary movements

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CHAPTER 17

Psychotherapeutic Drugs

Learning Objectives

1. Briefly discuss the various mental illnesses.2. Identify the various psychotherapeutic drug classes, such as anxiolytic drugs, antidepressants, mood-stabilizing drugs, and antipsychotics.3. Discuss the mechanisms of action, indications, therapeutic effects, adverse effects, toxic effects, drug interactions, contraindications, and cautions associated with the various psychotherapeutic drugs.4. Develop a nursing care plan that includes all phases of the nursing process for patients taking psychotherapeutic drugs.5. Develop patient education guidelines for patients receiving psychotherapeutic drugs.

Psychotherapeutic DrugsUsed in the treatment of emotional and mental disordersAbility to cope with emotions can range from occasional depression or anxiety to constant emotional distress When emotions significantly affect an individuals ability to carry out normal daily functions, treatment with a psychotherapeutic drug is a possible option

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Psychotherapeutic Drugs (contd)Three main emotional and mental disorders:AnxietyAffective disordersPsychoses

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Psychotherapeutic Drugs (contd) Types of psychotherapeutic drugs Antianxiety drugs Antimanic drugs Antidepressant drugs Antipsychotic drugs

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Biochemical ImbalanceOther biochemicals are necessary for normal mental functionGABAAcetylcholine (ACh)Sodium, potassium, magnesium

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AnxietyUnpleasant state of mind, characterized by a sense of dread and fearMay be based on actual anticipated experiences or past experiencesMay be exaggerated responses to imaginary negative situations

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Anxiety DisordersSix major anxiety disorders (persistent anxiety)Obsessive-compulsive disorder (OCD)Posttraumatic stress disorder (PTSD)Generalized anxiety disorder (GAD)Panic disorderSocial phobiaSimple phobia

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Affective Disorders (Mood Disorders)Changes in mood that range from mania (abnormally pronounced emotions) to depression (abnormally reduced emotions)Some patients may exhibit both mania and depression: bipolar disorder (BPD)

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PsychosisSevere emotional disorder that impairs the mental function of the affected individual to the point that the individual cannot participate in activities of daily livingHallmark: loss of contact with realityExamplesSchizophreniaDepressive and drug-induced psychoses

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Psychotherapeutics:Pathophysiology Biochemical imbalance theoryMental disorders are associated with abnormal levels of endogenous chemicals, such as neurotransmitters, in the brain

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Psychotherapeutics:Pathophysiology Biochemical imbalance theory (contd)Brain levels of certain neurotransmitters play an important role in maintaining mental healthCatecholaminesDopamineNorepinephrineIndolamines Serotonin Histamine

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Antianxiety DrugsReduce anxiety by reducing overactivity in CNSBenzodiazepinesDepress activity in the brainstem and limbic systemMiscellaneous drug: Buspirone (BuSpar)Nonsedating and nonhabit formingMay have drug interaction with SSRIs (serotonin syndrome)Do not administer with MAOIs

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Antianxiety Drugs (contd) Barbiturates and carbamates Previously used to treat anxiety Replaced by newer drugs

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Antianxiety Drugs: Indications Anxiety Insomnia Sedation Muscle spasms Seizure disorders Adjuncts in anesthesia Adjuvant therapy for depression Alcohol (ethanol) withdrawal

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Common Benzodiazepines diazepam (Valium) lorazepam (Ativan) alprazolam (Xanax) clonazepam (Klonopin) chlordiazepoxide (Librium)

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Common Benzodiazepines (contd)Midazolam (Versed)*Reduces anxiety and patients memory of painful procedures that do not require general anesthesia (moderate sedation)Injection only

*Limited to use as sedative and anesthetic during invasive medical orsurgical procedures

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Benzodiazepines Potentially habit-forming and addictive Should be used at lowest effective dosages and frequencies needed for symptom control

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Benzodiazepines: Adverse EffectsBenzodiazepine adverse effects are an overexpression of their therapeutic effects Decreased CNS activity, sedation Hypotension Drowsiness, loss of coordination, dizziness, headaches Nausea, vomiting, dry mouth, constipation Others

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Benzodiazepines: Overdose Dangerous when taken with other sedatives or alcohol Treatment is generally symptomatic and supportive Flumazenil may be used to reverse benzodiazepine effects

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Affective Disorder DrugsMood stabilizersUsed to treat bipolar disorderInvolves cycles of mania, hypomania, and depressionAntidepressantsUsed to treat depression

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Mood Stabilizers: Antimanic DrugsLithium is the drug of choice for the treatment of mania It is thought to potentiate serotonergic neurotransmission May be used with other medications to stabilize mood Narrow therapeutic range: maintenance serum levels should range between 0.6 and 1.2 mEq/L Monitor sodium levels

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Depression Etiology Biogenic amine hypothesis Depression and mania are caused by an alteration in neuronal and synaptic catecholamine concentration at adrenergic receptor sites in the brainDepression: deficiency of catecholamine, especially norepinephrineMania: excess amines

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Depression (contd) Etiology (contd)Permissive hypothesis Affective disorders are caused by decreased concentrations of serotoninDepression results from decreases in both serotonin and catecholamine levelsMania results from increased catecholamine but decreased serotonin levels

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Depression (contd) EtiologyDysregulation hypothesis Depression and other affective disorders result from a failure in the regulation of catecholamine activity

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AntidepressantsTricyclic antidepressantsMonoamine oxidase inhibitors (MAOIs)Newer-generation antidepressantsSelective serotonin reuptake inhibitors (SSRIs)Second- and third-generation antidepressants

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Tricyclic Antidepressants:First-Generation AntidepressantsHave largely been replaced by SSRIs as first-line antidepressant drugsConsidered second-lineFor patients who fail with SSRIs or other newer-generation antidepressantsAs adjunct therapy with newer-generation antidepressants

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Common Tricyclicsamitriptyline (Elavil, Endep)doxepin (Sinequan)imipramine (Tofranil)desipramine (Norpramin)nortriptyline (Aventyl, Pamelor)Others

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Mechanism of ActionBlock reuptake of neurotransmitters, causing accumulation at the nerve endingsIt is thought that increasing concentrations of neurotransmitters will correct the abnormally low levels that lead to depression

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Drug EffectsBlockade of norepinephrine reuptakeAntidepressant,* tremors, tachycardia, othersBlockade of serotonin reuptakeAntidepressant,* nausea, headache, anxiety, sexual dysfunction

*Desired therapeutic effects

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IndicationsDepressionChildhood enuresis (imipramine)Obsessive-compulsive disorders (clomipramine)Adjunctive analgesics for chronic pain conditions, such as trigeminal neuralgia

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Adverse EffectsSedationImpotenceOrthostatic hypotensionOthersOlder patientsDizziness, postural hypotension, constipation, delayed micturation, edema, muscle tremors

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OverdoseLethal70% to 80% die before reaching the hospitalCNS and cardiovascular systems are mainly affectedDeath results from seizures or dysrhythmias

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Overdose (contd)No specific antidoteDecrease drug absorption with activated charcoalSpeed elimination by alkalinizing urineManage seizures and dysrhythmiasBasic life support

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MAOIsHighly effectiveConsidered second-line treatment for depression, not responsive to cyclicsDisadvantage: potential to cause hypertensive crisis when taken with tyramine

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MAOIs (contd)Examplesphenelzine (Nardil)tranylcypromine (Parnate)

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MAOIs: Mechanism of ActionInhibit the MAO enzyme system in the CNSAmines (dopamine, serotonin, norepinephrine) are not broken down, resulting in higher levels in the brainResult: alleviation of symptoms of depression

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MAOIs: IndicationsDepression, especially types characterized by reverse vegetative symptoms such as increased sleep and appetiteDepression that does not respond to other drugs such as tricyclics

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MAOIs: Adverse EffectsFew adverse effectsorthostatic hypotension most common Palpitations Drowsiness Headache Nausea Impotence Tachycardia Dizziness Insomnia Anorexia Blurred vision

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MAOIs: OverdoseSymptoms appear 12 hours after ingestionTachycardia, circulatory collapse, seizures, comaTreatment: protect brain and heart, eliminate toxinGastric lavageUrine acidificationHemodialysis

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Hypertensive Crisis and TyramineIngestion of foods or drinks with tyramine leads to hypertensive crisis, which may lead to cerebral hemorrhage, stroke, coma, or deathAvoid foods that contain tyramine!Aged, mature cheeses (cheddar, blue, Swiss)Smoked/pickled or aged meats, fish, poultry (herring, sausage, corned beef, salami, pepperoni, pat)Yeast extractsRed wines (Chianti, burgundy, sherry, vermouth)Italian broad beans (fava beans)

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MAOIsConcurrent use of MAOIs and SSRIs may lead to serotonin syndromeIf the decision is made to switch to an SSRI, there must be a 2- to 5-week wash-out period between MAOI therapy and SSRI therapy

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Newer-Generation AntidepressantsFewer adverse effects than tricyclics and MAOIsVery few drug-drug or drug-food interactionsStill take about 4 to 6 weeks to reach maximum clinical effectivenessNow considered first-line drugs for depression

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Newer-Generation Antidepressants (contd)trazodone (Desyrel)bupropion (Wellbutrin)SSRIsfluoxetine (Prozac)paroxetine (Paxil)sertraline (Zoloft)fluvoxamine (Luvox)citalopram (Celexa) escitalopram (Lexapro)

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Newer-Generation Antidepressants (contd)

venlafaxine (Effexor)nefazodone (Serzone)mirtazapine (Remeron)duloxetine (Cymbalta)desvenlafaxine (Pristiq)

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SSRIs Mechanism of actionSelectively inhibit serotonin reuptakeLittle or no effect on norepinephrine or dopamine reuptakeResult in increased serotonin concentrations at nerve endingsAdvantage over tricyclics and MAOIs: little or no effect on cardiovascular system

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Newer-Generation Antidepressants: IndicationsDepressionBipolar disorderObesityEating disordersObsessive-compulsive disorder

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Newer-Generation Antidepressants: Indications (contd)Panic attacks or disordersSocial anxiety disordersPosttraumatic stress disorders (PTSDs)MyoclonusTreatment of various substance abuse problems (bupropion [Zyban] is used for smoking cessation treatment)

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Newer-Generation Antidepressants: Adverse EffectsBody SystemEffects CNSHeadache, dizziness, tremor, nervousness, insomnia,* fatigueGINausea, diarrhea,constipation, dry mouthOtherSexual dysfunction, weight gain*, weightloss*, sweating

*Most common and bothersome

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Serotonin Syndrome

SymptomsDelirium, tachycardia, hyperreflexia, shivering, agitation, sweating, muscle spasms, coarse tremorsSymptoms of severe casesHyperthermia, seizures, renal failure, rhabdomyolysis, dysrhythmias, disseminated intravascular coagulation (DIC)

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Newer-Generation Antidepressants: Drug InteractionsHighly bound to plasma proteinsCompete with other protein-binding drugs, resulting in more free, unbound drug to cause a more pronounced drug effectInhibition of cytochrome P-450 systemMAOIs

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AntipsychoticsDrugs used to treat serious mental illnessBehavioral problems or psychotic disordersHave been known as tranquilizers or neuroleptics

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Antipsychotics (contd)Thioxanthenes: thiothixene (Navane)Butyrophenones: haloperidol (Haldol)Dihydroindolones: molindone (Moban)Dibenzoxazepine: loxapine (Loxitane)Phenothiazines: three structural groups Atypical antipsychotics: new class

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Mechanism of ActionBlock dopamine receptors in the brain (limbic system, basal ganglia)areas associated with emotion, cognitive function, motor functionDopamine levels in the CNS are decreasedResult: tranquilizing effect in psychotic patients

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Atypical Antipsychotics:Second-Generation Antipsychoticsclozapine (Clozaril)risperidone (Risperdal)olanzapine (Zyprexa)quetiapine (Seroquel)ziprasidone (Geodon)aripiprazole (Abilify)paliperidone (Invega)

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Atypical Antipsychotics:Mechanism of ActionBlock specific dopamine receptors: dopamine-2 (D2) receptorsAlso block specific serotonin receptors: serotonin-2 (5HT2) receptorsThis is responsible for their improved efficacy and safety profiles

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Antipsychotics: IndicationsTreatment of serious mental illnessesBipolar affective disorderDepressive and drug-induced psychosesSchizophreniaAutismMovement disorders (such as Tourettes syndrome)Some medical conditionsNausea, intractable hiccups

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Adverse EffectsBody SystemAdverse EffectsCNSSedation, deliriumCardiovascularOrthostatic hypotension, syncope, dizziness, ECG changesDermatologicPhotosensitivity, skin rash, hyperpigmentation, pruritus

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Adverse Effects (contd)Body SystemAdverse EffectsGIDry mouth, constipation

GUUrinary hesitancy or retention, impaired erection

HematologicLeukopenia andagranulocytosis

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Adverse Effects (contd)Body SystemAdverse EffectsMetabolic/endocrineGalactorrhea, irregular menses,increased appetite, polydipsia

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Adverse Effects (contd)Neuroleptic malignant syndrome (NMS)Potentially life threateningHigh fever, unstable BP, myoglobinemiaExtrapyramidal symptoms (EPS)Involuntary muscle symptoms similar to those of Parkinsons diseaseAkathisia (distressing muscle restlessness)Acute dystonia (painful muscle spasms)Treated with benztropine (Cogentin) and trihexyphenidyl (Artane)

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Adverse Effects (contd)Tardive dyskinesia (TD)Involuntary contractions of oral and facial musclesChoreoathetosis (wavelike movements of extremities)Occurs with continuous long-term antipsychotic therapy

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Herbal Products: St. Johns WortUsed for depression, anxiety, sleep disorders, nervousnessMay cause GI upset, fatigue, dizziness, confusion, dry mouth, photosensitivitySevere interactions if taken with MAOIs and SSRIs; many other drug interactionsFood-drug interaction with tyramine-containing foods

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Herbal Products: GinsengThree varieties; has been used for over 5000 yearsUses: stress reduction, improvement of physical endurance and concentrationMay cause elevated BP, chest pain, palpitations, anxiety, insomnia, headache, GI symptomsInteractions with anticoagulants, immunosuppressants, anticonvulsants, antidiabetic drugs

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Psychotherapeutic Drugs: Nursing ImplicationsBefore beginning therapy, assess physical and emotional status of patientsObtain baseline vital signs, including postural BP readingsObtain liver and renal function tests

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Psychotherapeutic Drugs: Nursing Implications (contd)Assess for possible contraindications to therapy, cautious use, and potential drug interactionsAssess for LOC, mental alertness, potential for injury to self and othersCheck the patients mouth to make sure oral doses are swallowed

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Psychotherapeutic Drugs: Nursing Implications (contd)Provide simple explanations about the drug, its effects, and the length of time before therapeutic effects can be expectedAdvise patients to avoid abrupt withdrawalAdvise patients to change positions slowly to avoid postural hypotension and possible injury

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Psychotherapeutic Drugs: Nursing Implications (contd)The combination of drug therapy and psychotherapy is emphasized because patients need to learn and acquire more effective coping skillsOnly small amounts of medications should be dispensed at a time to minimize the risk of suicide attemptsSimultaneous use of these drugs with alcohol or other CNS depressants can be fatal

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Psychotherapeutic Drugs: Nursing Implications (contd)Antianxiety drugsIn elderly patients, monitor closely for oversedation and profound CNS depression

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Psychotherapeutic Drugs: Nursing Implications (contd)AntidepressantsMany cautions, contraindications, and interactions exist pertaining to the use of antidepressantsInform patients that it may take several weeks to see therapeutic effectsMonitor patients closely during this time, assess for suicidal tendencies, and provide supportAssist elderly or weakened patients with ambulation and other activities because falls may occur because of drowsiness or postural hypotension

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Psychotherapeutic Drugs:Nursing Implications (contd) Antidepressants (contd)Tricyclics may need to be weaned and discontinued before undergoing surgery to avoid interactions with anesthetic drugsMonitor for adverse effects, and discuss with patientsEncourage patients to wear medication ID badges naming the drugs being taken

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Psychotherapeutic Drugs: Nursing Implications (contd) Antidepressants (contd)Caffeine and cigarette smoking may decrease effectiveness of medication therapyInstruct patients and family regarding tyramine-containing foods and signs and symptoms of hypertensive crisis

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Psychotherapeutic Drugs: Nursing Implications (contd)Antipsychoticsphenothiazines Instruct patients to wear sunscreen because of photosensitivityTell patients to avoid taking antacids or antidiarrheal preparations within 1 hour of a doseInform patients to avoid alcohol or other CNS depressants with these medications

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Psychotherapeutic Drugs: Nursing Implications (contd) Antipsychoticsphenothiazines (contd)Long-term haloperidol therapy may result in tremors, nausea, vomiting, or uncontrollable shaking of small muscle groups; report these symptoms to the physician

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Psychotherapeutic Drugs: Nursing Implications (contd)Antipsychoticsphenothiazines (contd)Oral forms may be taken with meals to decrease GI upsetThese drugs may cause drowsiness, dizziness, or fainting; instruct patients to change positions slowly

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Psychotherapeutic Drugs: Nursing Implications (contd)Monitor for therapeutic effects Monitor mental alertness, cognition, affect, mood, ability to carry out activities of daily living, appetite, and sleep patternsMonitor potential for self-injury during the delay between the start of therapy and symptomatic improvement

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Psychotherapeutic Drugs: Nursing Implications (contd)Monitor for therapeutic effects (contd)For anxiolyticsImproved mental alertness, cognition, and moodFewer anxiety and panic attacksImproved sleep patterns and appetiteLess tension and irritability; fewer feelings of fear, impending doom, and stressMore interest in self and others

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Psychotherapeutic Drugs: Nursing Implications (contd) Monitor for therapeutic effects (contd)For antidepressants Improved sleep patterns and nutritionIncreased feelings of self-esteemDecreased feelings of hopelessnessIncreased interest in self and appearanceIncreased interest in daily activitiesFewer depressive manifestations or suicidal thoughts/ideations

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Psychotherapeutic Drugs: Nursing Implications (contd)Monitor for therapeutic effects (contd)For antipsychotics Improved mood and affectAlleviation of psychotic symptoms and episodesDecreased hallucinations, paranoia, delusions, garbled speech, and inability to cope

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Psychotherapeutic Drugs: Nursing Implications (contd)Monitor for therapeutic effects (contd)For lithium Less maniaTherapeutic lithium levels of 0.6 to 1.2 mEq/L

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