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psychopharmacology

2. Neuroscience. Nervous system Limbic system

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psychopharmacology

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    1. 1 Psychopharmacology Therapeutic vs. toxic dosage levels Side effects Adverse effects Interactions Use with the elderly, during Use during pregnancy Patient teaching nonpsychopharmacological interventions

    2. 2 Genetic pathway responsible for vulnerability is present in one twin but not the otherGenetic pathway responsible for vulnerability is present in one twin but not the other

    3. 3 Neurotransmitter Neurotransmitter - combine with a specific receptor; Relay a chemical message to the receptor cell Drugs act on neurotransmitters Agonist – activating cell function; to accelerate or slow cellular processes Antagonist – prevent natural or other substances from activating cell function Affinity – binding between drug and receptor Refractoriness - desensitization of cells to a drug over time Neurotransmitter - combine with a specific receptor; enhance or inhibit nerve message transmission; Relay a chemical message to the receptor cell Agonist is a drug that initiates a therapeutic effect by binding to a receptor. It may affect other body functions. Ie. Lithium -> thyroid or kidney problem Refractoriness – desensitization of cells to a drug over time Neurotransmitter - combine with a specific receptor; enhance or inhibit nerve message transmission; Relay a chemical message to the receptor cell Agonist is a drug that initiates a therapeutic effect by binding to a receptor. It may affect other body functions. Ie. Lithium -> thyroid or kidney problem Refractoriness – desensitization of cells to a drug over time

    4. 4 Neurotransmitters and Related Mental Disorders Dopamine ? Norepinephrine ? Serotonin ? Acetylcholine ? Gamma-aminobutyric acid (GABA) ? Schizophrenia Depression Depression Alzheimer’s disease Anxiety Dopamine is important in conceptualizing the pathology & tx of schizophrenia & parkinsonism. Patients who are taking antiparkinson agents should not stop taking the drug abruptly Dopamine depletion -> impairment in complex motor activities Norepinephrine inbalance -> mood disorderDopamine is important in conceptualizing the pathology & tx of schizophrenia & parkinsonism. Patients who are taking antiparkinson agents should not stop taking the drug abruptly Dopamine depletion -> impairment in complex motor activities Norepinephrine inbalance -> mood disorder

    5. 5 Pharmacokinetics - Absorption PO, IV, IM,…- Absorption qid, tid, bid, … - drug level in the blood Individual condition - sex - female: fat age - older: health - congestive heart failure, GI, Others - exercise

    6. 6 Pharmacokinetics - Distribution Target tissue Cardiac output - electric imbalance, CHF, chr pulmonary dis Serum protein binding Half-life of the drug Pregnancy Lipid solubility - cross BBB Steady state - 4-5 half-lifeLipid solubility - cross BBB Steady state - 4-5 half-life

    7. 7 Pharmacokinetics - Metabolism Break down or metabolize into other compound - liver convert into other active substance – liver

    8. 8 Pharmacokinetics - Excretion Proper excretion = less toxicity Kidney - main excretion organ Others - GI, skin, lungs, sweat glands Tissue perfusion rate - shock, hemorrhage Diseases - renal, liver ... Urinary pH - acidic urine -amphetamine alkaline urine- barbiturates

    9. 9 Phases of Treatment Initiation Stabilization Maintenance Medication-free

    10. 10 Nursing Responsibilities Monitor the S & S of the disease state Monitor for common, expected or worrisome side effects of medications Preventing adverse drug reactions Evaluate compliance Judge the appropriateness of the regimen Recommend needed changes Provide pt & family education Realistic outcome of the teaching is: pt able to state the purpose, dose, significant side effects of each drugRealistic outcome of the teaching is: pt able to state the purpose, dose, significant side effects of each drug

    11. 11 Patient Education Compliance - effectiveness, symptom control Side-effect - inevitable, unpleasant, temporary; only a few are life threatening Education - encourages compliance; Medications are not magic bullet Balance with information - too much or inappropriate Health beliefs model- what is the benefit of taking med Regular checkups and test 92% of rehospitalizations are r/t nonadherence to medication schedule Education needs- 72% - do not understand their medication 8% - know the name, dosage schedule, & desired effect; what effects are visible. what can be felt, and what the possibilities are of becoming drug-dependent 92% of rehospitalizations are r/t nonadherence to medication schedule Education needs- 72% - do not understand their medication 8% - know the name, dosage schedule, & desired effect; what effects are visible. what can be felt, and what the possibilities are of becoming drug-dependent

    12. 12 Classes of psychotropic medication Antipsychotic medications Antidepressant medications Mood-stabilizing drugs Anti-anxiety medications Psychostimulants

    13. 13 Antipsychotics - typical 1950 - Chlorpromazine (Thorazine) Mechanism - Block dopamine receptors effective in treating (+) symptoms ie. alterations of perception- hallucinations thought disturbance - delusion activity - agitation

    14. 14 Atypical agents 1980’s - Targets dopamine and serotonin, may work on both (+) & (-) symptoms Better tolerated, less side effects, better compliance, less cognitive impairment, better efficacy in negative symptoms of schizophrenia

    15. 15 Typical & Atypical Phenothiazines Thorazine 200-800 mg qd half-life: 30 hours Peak 2-4 hours Non-phenothiazines Haldol 1-15 mg qd half-life: 21-24 hours Higher risk of EPSs Clozaril 150-450 mg qd, watch for fever, agranulocytosis Risperdal 2-8 mg qd Less sedation Zyprexa 5-10 mg qd smaller dose for the elderly & liver dis. pt Clozaril is metabolized in the liver by the cytochrome enzyme system, dosage reductions may be required in pts receiving other drugs metabolized by the same system. That includes antidepressant medications, carbomazepine, and the antiarrhythmics propafenone (Rythmol), flecainide (Tambocor), and quinidine (Quinidex). Olanzapine (Zyprexa) serum half-life increases by about 50% in pts over 65 & in pts with liver dysfunciton. Those clients may require smaller than average doses.Clozaril is metabolized in the liver by the cytochrome enzyme system, dosage reductions may be required in pts receiving other drugs metabolized by the same system. That includes antidepressant medications, carbomazepine, and the antiarrhythmics propafenone (Rythmol), flecainide (Tambocor), and quinidine (Quinidex). Olanzapine (Zyprexa) serum half-life increases by about 50% in pts over 65 & in pts with liver dysfunciton. Those clients may require smaller than average doses.

    16. 16 Neurological complications of antipsychotics Pseudoparkinsonism - muscle rigidity Extrapyramidal Side Effects (EPSEs)- Akathisia* - motor restlessness Dyskinesia - jerky motion Dystonia -muscle rigidity; life-threatening Tardive dyskinesia – facial grimacing tics, tongue writhing, lip smacking, puckering… - irreversible, high dose, older, females, TD includes abnormal movements in the neck, trunk, and limbs Primary hazard – EPSEs & tardive dyskinesiaTD includes abnormal movements in the neck, trunk, and limbs Primary hazard – EPSEs & tardive dyskinesia

    17. 17 Other adverse effects (I) Anticholinergic effect – dry mouth, blurred vision, constipation, Neuroleptic maliganant syndrome (NMS) - rare, life-threatening altered consciousness, hyperthermia, muscle rigidity, tachycardia, sweating discontinue the medication reverse the dopamine-blocking effects of antipsychotics (ie bromocriptine) or muscle relaxant (ie dantrolene)

    18. 18 Other adverse effects (II) Seizures - threshold ? Hyperprolactinemia - breast engorgement, falactorrhea, amenorrhea, impotence, azospermia Hepatic changes - jaundice, nausea, fever, chill, general malaise, itching Photosensitivity Weight gain - 3-9 lbs

    19. 19 Interventions for EPSEs Tolerance usually ? by the 3rd month Lower dose of drug Add a drug to treat EPSE, then taper after 3 M on the antipsychotics Use a drug with a lower EPSE profile Pt education and support

    20. 20 Interventions for Dystonia Occur suddenly; frightening; painful Common in children and young males With high potency drugs Medication - IV > PO; Have respiratory support available taper antipsychotics gradually to prevent withdrawal dyskinesia

    21. 21 Neuroleptic Malignant Syndrome Drug-induced disorder; Be recognized in 1980s Incidence – 0.2%; uncommon but potentially life-threatening Risk factors- dehydration, agitation, catatonia, mood disorders, organic brain syndromes, drug or alcohol withdrawal states, previous NMS episodes, drugs given by injection Exercise -> dehydrationExercise -> dehydration

    22. 22 Characteristics of NMS Disturbances in mental status, temperature regulation, & autonomic and extrapyramidal functions Mental Status – catatonia Vital signs – tachycardia, unstable BP Extrapyramidal functions – tremors, dysarthria, dysphagia, drooling Lab – increased WBC, elevated blood enzymes ie. Creatine phosphokinase, Dysarthria – difficulty in articulating single sounds or phonemes of speech Disphagia – difficulty in swallowingDysarthria – difficulty in articulating single sounds or phonemes of speech Disphagia – difficulty in swallowing

    23. 23 Interventions for NMS Potential fatal - tachycardia, fever, sweating, muscle rigidity, incontinence, stupor, aspiration pneumonia, leukocytosis, renal failure, Common with high potency drugs and in dehydrated pts Discontinue all drugs, supportive symptomatic care (H2O; BT?; hemodialysis) antipsychotics can be reintroduced later

    24. 24 Interventions for Agranulocytosis Emergency case; occur abruptly Fever, malaise, ulcerative sore throat, leukopenia High incidence with clozapine (1-2%) - 1wk prescription a time - check CBC Discontinue drug immediately May need isolation and antibiotics

    25. 25 Interventions for Photosensitivity Use sunscreen and sunglasses Cover body with clothing Reassurance normal vision typically returns in a few days tolerance develops

    26. 26 Interventions for Anticholinergic effect S/S: constipation, dry mouth, blurred vision, orthostatic hypotension, tachycardia, urinary retention, nasal congestion Avoid hazard task Fluid, mouth rinse, hard candy, sugar-free gum. Check mouth sore Fluid, fiber, exercises, monitor BM habits, use stool softeners,

    27. 27 Interventions for Weight Gain Increase exercises Reduce calorie diet if indicated May need to change class of drug

    28. 28 AIM- Abnormal Involuntary Movement incidence of TD has been relatively low in recent years, changes in prescribing may result in increased occurrence. AIMS (Abnormal Involuntary Movement Scale) http://www.psychiatrictimes.com/scales/movement_disorders/AIMS_LandingPage.jhtml

    29. 29 Drug interactions Central nervous system depressants i.e. opiates, barbiturates, alcohol -> sedative effective ? Antihypertensives - hypotensive effects ? Caffeine - antipsychotic drug effect ? Cigarette smoking -blood level of antipsychotics ? Lithium - possible additive toxic effect Anticholinergic - absorption of antipsychotics ? Benzodiazepine group & alcohol Beta-blockers i.e., clonidine (Catapres) Benzodiazepine group & alcohol Beta-blockers i.e., clonidine (Catapres)

    30. 30 Anticholinergic drugs - for EPSEs Benztropine (Cogentin): 1-4mg, qd or bid. PO or IM Biperiden (Akineton): 2-6mg, qd, bid, tid Trihexyphenidyl (Artane): 5-15mg/d Procyclidine (Kemadrin): 6-20mg/d Ethopropazine (Parsidol): 600mg/d Anticholinergic drugs ? acetylcholine? Anticholinergic drug ie Cogentin -> impairment in memory & learning Alzheimer’s dis maybe related to decreased acetylcholine Anticholinergic drug ie Cogentin -> impairment in memory & learning Alzheimer’s dis maybe related to decreased acetylcholine

    31. 31 Other drugs to treat EPSEs Antihistamine Diphenhydramine (Benadryl) 25-300/d; PO, IM, IV Dopamine Agonist Amantadine (Symmetrel) 100-3000mg/d; PO Benzodiazepines Diazepam (Valium) 2-6 mg/d; PO, IV Lorazepam (Ativan) 0.5-2 mg/d; PO, IM Clonazepam (Klonopin) 1-4; PO Benadryl has anticholinergic effectBenadryl has anticholinergic effect

    32. 32 Types of Antidepressants Monoamine Oxidase inhibitors (MAO inhibitors) TCAs (Tricyclic Antidepressants) SSRI (Selective Serotonin Reuptake inhibitor)

    33. 33 Pt taking Parnate, a MAOI should avoid foods containing tyramine ie cheese, red wine, avocado MAOI -> hypotension For elderly, Nardil is the most commonly prescribed one for the elderlyPt taking Parnate, a MAOI should avoid foods containing tyramine ie cheese, red wine, avocado MAOI -> hypotension For elderly, Nardil is the most commonly prescribed one for the elderly

    34. 34

    35. 35 Other Foods to be avoided – Chocolate, Non-fresh, fermented, or preserved fish, liver, and meats Red wine, Yeast extracts, Yogurt & sour cream, Avocado. tyramine (amino acid) is the culprit Other Foods to be avoided – Chocolate, Non-fresh, fermented, or preserved fish, liver, and meats Red wine, Yeast extracts, Yogurt & sour cream, Avocado. tyramine (amino acid) is the culprit

    36. 36 S/S of Hypertensive Crisis on MAOIs Warning S - BP?; palpitations; Headache Symptoms - sudden BP?; Explosive occipital headache Head and face are flushed & feel full Palpitation, chest pain Sweating, fever, nausea, vomiting Dilated pupils, photophobia

    37. 37 TX of Hypertensive Crisis on MAOIs Hold MAOIs doses Do not lie down (elevates BP in head) IM chlorpromazine 100mg, repeat if necessary (to block norepinephrine) IV phentolamine, (to bind with norepinephrine receptor sites, blocking norepinephrine) Manage fever by external cooling techniques Evaluate diet, adherence, and teaching

    38. 38 Pt taking amitriptyline (Elavil) has to be watched for orthostatic hypotension, arrhythmias, and eye painPt taking amitriptyline (Elavil) has to be watched for orthostatic hypotension, arrhythmias, and eye pain

    39. 39 Common Side effects of TCAs Mechanism – blockade of acetylcholine Drowsiness, dizziness, tachycardia, skin rashes, dry moth, constipation, and urinary retention, Risk of mortality with overdose is high

    40. 40

    41. 41 A Common side effect of SSRI that pt may be reluctant to report is sexual dysfunctionA Common side effect of SSRI that pt may be reluctant to report is sexual dysfunction

    42. 42 Side effects of the SSRI Anxiety & restlessness Constipation Dry mouth Headache Nausea & vomiting Sedation Sexual dysfunction To deal with restlessness of the side effect, the intervention includes decreasing the dosageTo deal with restlessness of the side effect, the intervention includes decreasing the dosage

    43. 43 Overview of antidepressants 1st choice - SSRI Take 2-4 weeks to be effective of TCAs Abrupt withdrawal of TCAs ?headache, nausea, malaise MAOIs uses could not take “tyramine” related food ? hypertensive crisis 14 days - change drugs from TCAs to MAOIs

    44. 44 Valproic acid (Depakote) is an anticonvulsant. Rapid onset, can be used as initial treatment, effective in bipolar disorder subtype. Side effects include transient hair loss, wright gain, tremors, GI upset, dose-related throbocytopenia, Lithium – more than 40 years of clinical experience, most effective for euphoric mania and hypomania, can reduce mortality by decreasing suicide, inexpensive Side effect include nonresponse in 30-50% of cases, narrow therapeutic index, slow onset of action, side effects very common, high rate of noncompliance, less effective in bipolar subtype. Carbamazepine: more rapid onset than lithium, maybe effective in difficult-to-treat cases, maybe effective as adjunct therapy in acute mania, generally well tolerated Side effet: simulates own oxidative metabolism (autoinduction), blood dyscrasias, skin reactions, complex drug interactions, sedation, poor coordination, hyponatremia (poorly tolerated by elderly). Valproic acid (Depakote) is an anticonvulsant. Rapid onset, can be used as initial treatment, effective in bipolar disorder subtype. Side effects include transient hair loss, wright gain, tremors, GI upset, dose-related throbocytopenia, Lithium – more than 40 years of clinical experience, most effective for euphoric mania and hypomania, can reduce mortality by decreasing suicide, inexpensive Side effect include nonresponse in 30-50% of cases, narrow therapeutic index, slow onset of action, side effects very common, high rate of noncompliance, less effective in bipolar subtype. Carbamazepine: more rapid onset than lithium, maybe effective in difficult-to-treat cases, maybe effective as adjunct therapy in acute mania, generally well tolerated Side effet: simulates own oxidative metabolism (autoinduction), blood dyscrasias, skin reactions, complex drug interactions, sedation, poor coordination, hyponatremia (poorly tolerated by elderly).

    45. 45 Weight gain is the most popular side effectWeight gain is the most popular side effect

    46. 46

    47. 47 Use of Lithium Thyroid & kidney screening Regular levels - prophylactic Drink a lot of water No pregnancy -> fetal heart problems 1st trimester -> birth defects no nursing - excrete from milk blood volume increase -> hard to measure no use in age under 8 or in seniors, accumulation in bone tissue, effect of renal & thyroid function; meta? in seniors

    48. 48 Side-effect of Lithium Body Image- weight gain ( 60% of pt) Cardiac - ECG change but not significant CNS - fine hand tremor (50% of pt); fatigue, headache, mental dullness, lethargy Skin - acne, rash Endocrine - hypothyroid (5% of pt); DM Renal - Polyuria (60% of pt) - H2O?

    49. 49 Common causes for Li+? Decrease sodium intake Fluid and electrolyte loss, sweating, diarrhea, dehydration, fever, vomiting Exercise – marathons Medical illness ie poor renal function Overdose Nonsteroidal anti-inflammatory drug therapy Serum level of sodium may affect the maintenance of therapeutic serum levels of lithium Diuretic therapySerum level of sodium may affect the maintenance of therapeutic serum levels of lithium Diuretic therapy

    50. 50 Ways to maintain Li level Stabilize dosing schedule - dividing doses or use of sustained-release capsules Ensure adequate dietary sodium and fluid intake (2-3 L/day) Replace fluid & electrolytes lost during exercise or gastrointestinal illness. Monitor S/S of lithium side effects and toxicity Forget dose - retake if <2 hr; skip if >2hr Never double up Follow up on lithium level –every 2 months

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    52. 52 Tolerance : Ativan- short acting benzodiazepines. Metabolized more efficiently Withdrawal syndrome (including withdrawal seizure) can occur in persons removed form an antianxiety agent after 30 days or more of use, benzodiazpines should be withdrawn slowly over several weeks. Tolerance : Ativan- short acting benzodiazepines. Metabolized more efficiently Withdrawal syndrome (including withdrawal seizure) can occur in persons removed form an antianxiety agent after 30 days or more of use, benzodiazpines should be withdrawn slowly over several weeks.

    53. 53 Anti-Anxiety drugNon benzodiazepines- Buspirone Buspirone (BuSpar) not a CNS depressant less danger of interaction with other CNS depressant i.e. alcohol no strong sedative-hypnotic effect Less drowsiness better tolerated than the benzodiazepines less potential for addiction Buspirone does not cause drowsiness. Buspirone does not cause drowsiness.

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    55. 55

    56. 56 Intervention for Benzodiazepine Withdrawal Symptoms Careful with tolerance, dependency, rebound insomnia/anxiety Tapered weekly at a rate of 25% Short-term use Contraindicated with drug or alcohol abuse

    57. 57 Patient Education What the most important thing in medication counseling? What; How; Why Common side-effects/ poorly controlled Health beliefs model – what is the benefits of taking the medication Relationship between anxiety and physiological reactions - sympathetic nerve system Relationship between anxiety and physiological reactions - sympathetic nerve system

    58. 58 Non-compliance Knowledge - purpose, side-effect, Pt’s beliefs, wishes, ideas of taking med Multiple daily dosing schedule Polypharmacy History of noncompliance Social isolation; Expense of drugs Lack of continuity of care

    59. 59 Non-compliance (II) Increased restrictions of pt’s lifestyle Unsupportive sig. others Remission of target symptoms unrealistic expectations Concurrent substance use potential stigmatization

    60. 60 Have a nice weekend

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