Introduction to Clinical Pharmacology Chapter 22 Antidepressant Drugs

1. Introduction to Clinical PharmacologyChapter 22Antidepressant Drugs

2. Introduction • Depression is described as a feeling of sadness, unhappiness, or “down in the dump” • Occasional episodes is normal, but Major Depressive Disorder (MDD) is called a mood disorder • Unipolar depression presents with dysphoric mood that interferes with daily functioning; will have at least 5 symptoms listed in Box 22.1 and need to occur daily or almost everyday for a period of 2 weeks or more • SSRIs; Serotonin/norepinephrine or dopamine/norepinephrine reuptake inhibitors (SNRIs or DNRIs) • Tricyclic Antidepressants (TCAs) • Monoamine oxidase inhibitors (MAOIs)

3. Tricyclic Antidepressants: Actions • Increase sensitivity in postsynaptic alpha (α)-adrenergic, serotonin receptors • Decrease sensitivity in presynaptic receptor sites • Make neurotransmission activity more effective • Inhibit or slow down the reuptake ofnorepinephrine or serotonin receptor systems in brain such as tricyclic antidepressants like amitriptyline and clomipramine • Selective serotonin reuptake inhibitors like fluoxetine and escitalopram exert their effects by inhibiting the reuptake of serotonin

5. Tricyclic Antidepressants: Uses • Used to treat episodes • Bipolar • Depressive disorder; obsessive-compulsive disorders; chronic neuropathic pain • Depression/anxiety disorders; enuresis; peptic ulcer disease; sleep apnea; panic disorder • Bulimia nervosa; premenstrual symptoms; dermatologic problems; psychotherapy—severe cases

8. Tricyclic Antidepressants: Adverse Reactions and Contraindications • Adverse reactions: sedation, dry mouth, visual disturbances, urinary retention, constipation, photosensitivity, dry eyes • TCA contraindications: hypersensitivity to drugs, patientson MAOI antidepressants, patients with myocardial infarction, children, lactating mothers; Sinequan contraindications—glaucoma, urinary retention

9. Tricyclic Antidepressants: Precautions • Used cautiously in patients with: • Cardiac disease, hepatic and/or renal impairment, hyperthyroid disease • History of seizure activity, narrow-angle glaucoma or increased intraocular pressure • Urinary retention, risk of suicidal ideation or behavior • Caution with elderly due possible cardiac related adverse reactions • Adolescence clients-with major depressive disorders have an increased risk of suicidal ideation when prescribed antidepressant medications

10. Tricyclic Antidepressants: Interactions #1

11. Tricyclic Antidepressants: Interactions #2

12. Monoamine Oxidase Inhibitors: Actions and Uses • Actions: increase in endogenous epinephrine, norepinephrine, dopamine, serotonin in nervous system; increase in neurohormones • Uses: depressive episodes, psychotherapy, bulimia, night terrors, migraine headaches, seasonal affective disorder, multiple sclerosis

14. Monoamine Oxidase Inhibitors: Adverse Reactions • Neuromuscular reactions: orthostatic hypotension, dizziness, vertigo, headache, blurred vision • Gastrointestinal (GI) and genitourinary (GU) system reactions: constipation, dry mouth, nausea, diarrhea, impotence • Serious adverse reaction: hypertensive crisis with foods containing tyramine-exhibit the following symptoms: stiff or sore neck, nausea, vomiting, headache, sweating (not chills), fever, chest pain, dilated pupils (not constricted), and bradycardia or tachycardia

15. Monoamine Oxidase Inhibitors: Contraindications and Precautions • Contraindications: elderly patients; hypersensitivity to drugs; pheochromocytoma; liver, kidney, or cerebrovascular disease; hypertension; history of headaches; congestive heart failure • Foods with tyramine are contraindicated when taking MAOIs such as cheeses, yogurt, red wine, among other foods • Caution: patients with impaired liver function; history of seizures; parkinsonian symptoms; diabetes; hyperthyroidism; risk of suicidal ideation or behavior

16. Monoamine Oxidase Inhibitors: Interactions #1

17. Monoamine Oxidase Inhibitors: Interactions #2

19. Selective Serotonin Reuptake Inhibitors #1 • Actions: stimulant to reverse depression • Uses: depressive episodes; bulimia nervosa; panic, premenstrual, posttraumatic stress disorders; anxiety and social phobias; Raynaud disease; migraine headaches; diabetic neuropathy; hot flashes • Paroxetine is used for depressive disorders and OCD; adverse reactions include headache, tremors, somnolence, nervousness, dizziness, insomnia, nausea, diarrhea, constipation, dry mouth, sweating, weakness, and sexual dysfunction. • Adverse reactions • Neuromuscular reactions: somnolence, dizziness, headache, insomnia, tremor, weakness

21. Selective Serotonin Reuptake Inhibitors #2 • Gastrointestinal, genitourinary system reactions: Constipation, dry mouth, nausea, pharyngitis, runny nose, abnormal ejaculation • Contraindications: hypersensitivity to drugs; pregnancy category C; patients taking cisapride, pimozide, or carbamazepine should not take fluvoxamine (Prozac) • Precautions: diabetes mellitus; cardiac disease; impaired liver or kidney function; risk of suicidal ideation or behavior

22. Selective Serotonin Reuptake Inhibitors: Interactions

23. SSRIS or DNRIs : Actions and Uses/Adverse Reactions • Affect neurotransmission of serotonin, norepinephrine, dopamine • Uses: depressive episodes, anxiety disorders, neuropathic pain, enhancing weight loss, treating aggressive behaviors, menstrual disorders, cocaine withdrawal, alcohol cravings, fibromyalgia, stress incontinence • Duloxetine-can be used for depression, diabetic peripheral neuropathy; fibromyalgia; stress incontinence • Adverse Reactions- that may occur with trazodone (a SNRI/DNRI): priapism, drowsiness, dizziness, dry mouth, nausea, vomiting, constipation, fatigue, and nervousness. Sexual dysfunction is a possible adverse reaction to paroxetine. Insomnia and diarrhea are possible adverse reactions to SSRIs.

24. Miscellaneous Antidepressants: Adverse Reactions • Neuromuscular reactions: somnolence, migraine headaches, hypotension, dizziness, lightheadedness, vertigo, blurred vision, photosensitivity, insomnia, nervousness or agitation, tremor • Gastrointestinal reactions: nausea, dry mouth, anorexia, thirst, diarrhea, constipation, bitter taste • Generalized body system reactions • Mood Stabilizer-Lithium used for Manic Depressive Disorder; levels need to be monitored toxicity can occur with levels above 1.5 mEq/L—should not be taken with antacids; dehydration, diarrhea, vomiting, taking diuretics can cause toxicity because of fluid volume deficit.

25. Miscellaneous Antidepressants: Contraindications and Precautions • Contraindications: patients on cisapride, pimozide, carbamazepine • Hypersensitivity drugs, maprotiline—seizure disorder • Precautions: cardiac disease; renal and/or hepatic impairment; hyperthyroid disease; risk of suicidal ideation or behavior

26. Miscellaneous Antidepressants: Interactions

28. Nursing Process: Assessment #1 • Preadministration assessment: • Obtain complete medical history • Assess mental status, subjective feelings, slowness to answer questions, monotone speech pattern, sadness or crying, potential for suicide • Perform physical assessment including blood pressure, pulse, respiratory rate, weight, suicidal thoughts • Check for thyroid function tests in chart • Ask about intent using simple, straightforward questions

29. Nursing Process: Assessment #2 • Ongoing assessment: • Monitor vital signs, report change to primary health care provider • Observe response to therapy • Document general summary: outward behavior, complaints, problems; compare previous notations, observations

30. Nursing Process: Nursing Diagnosis and Planning #1 • Self-Care Deficit Syndrome • Disturbed Sleep Pattern • Imbalanced Nutrition: Less Than Body Requirements • Risk for Suicide • Acute Pain • Imbalanced Fluid Volume especially those receiving Lithium Therapy

32. Nursing Process: Nursing Diagnosis and Planning #2 • The expected outcome includes an optimal response to therapy: • Reason for administration of antidepressant • Optimal response to drug therapy • Support patient for adverse drug reactions • Understanding of and compliance with prescribed therapeutic regimen

33. Nursing Process: Implementation #1 • Promoting an optimal response to therapy: • Observe patient for adverse reactions: notify primary health care provider • Observe behavioral changes during initial therapy when dosage increased, decreased • Patientswith depression: develop nursing care plan, antidepressants, keep patient lying down for 30 minutes after administering drug

34. Nursing Process: Implementation #2 • Monitoring and managing patient needs: • Self-care deficit syndrome • Assist when there is depression: no physical or emotional energy to perform self-care activities • Minimize injury risk: safe environment, assist in changing positions, assist in activities of daily living, encourage self-care, give positive feedback, write behavioral records at periodic intervals, frequency depends on hospital, unit guidelines

35. Nursing Process: Implementation #3 • Monitoring and managing patient needs (cont.) • Disturbed sleep pattern: promote sleep, promote wakefulness during day, shut drapes at night, keep them open during the day, help patientreorient to daytime/nighttime; give SSRIs in the morning due to possible insomnia • Imbalanced nutrition: Less than body requirements: • Monitor and increase fluid/dietary intake, monitor weight loss/gain, good oral hygiene, frequent sips of fluids, sugarless gum

36. Nursing Process: Implementation #4 • Monitoring and managing patientneeds (cont.) • Strict dietary control: foods containing tyramine not to be eaten by patientson MAOIs, no food from outside • Risk for suicide: Well-supervised environment; wait for therapeutic effect; report expressions of guilt, hopelessness, helplessness, insomnia, weight loss, direct/indirect threats of suicide; care while swallowing

37. Nursing Process: Implementation #5 • Monitoring and managing patient need (cont.) • Acute pain: • Drugs: trazodone, priapism—impotence, prolonged, inappropriate penile erection, injection of alpha-adrenergic stimulants, surgical intervention

38. Nursing Process: Implementation #6 • Educating the patient and family • Managing reactions; patients—continue proper drug regimen; evaluate ability to take responsibility of drugs; explain adverse reactions • Teaching plan: inform primary health care provider, dentist; dizziness: rise slowly out of bed, chair; help changing positions; relieve dry mouth: frequent sips of water, sucking hard candy, chewing gum

39. Nursing Process: Implementation #7 • Educating the patientand family (cont.) • Teaching plan: report unusual changes, physical effects; avoid prolonged exposure to sunlight or sunlamps; male patients: if experiencing prolonged, inappropriate, painful erections, stop drug, notify primary health care provider • Remember to take lithium with food or immediately after meals to avoid stomach upset. Drink at least 10 large glasses of fluid each day and add extra salt to food if permissible.

40. Nursing Process: Implementation #8 • Evaluation: • Patient: perform self-care • Adverse reactions: identified, reported to primary health care provider, managed successfully—appropriate nursing interventions • Patient verbalizes treatment modalities, importance of continued follow-up care • Patient and family demonstrate drug regimen

41. NURSING ALERTS • Although the TCAs are not considered antipsychotic agents, the drug amoxapine has been associated with tardive dyskinesia and neuroleptic malignant syndrome (NMS). Tardive dyskinesia is a syndrome of involuntary movement that may be irreversible. Symptoms of NMS are similar and include muscle rigidity, altered mental status, and autonomic system problems, such as tachycardia or sweating. These syndromes tend to occur more readily in elderly women; the drug should be discontinued, the primary health care provider notified immediately, and treatment of adverse effects begun quickly. • The TCAs can cause cardiac-related adverse reactions, such as tachycardia and heart block. Give these drugs with caution to older adults or the person with pre-existing cardiac disease

42. NURSING ALERTS • The smoking cessation product Zyban is a form of the antidepressant drug bupropion. Smokers should not use Zyban if they are currently taking bupropion for management of depression because of the possibility of bupropion overdose. • One of the earliest symptoms of hypertensive crisis is headache (usually occipital), followed by a stiff or sore neck, nausea, vomiting, sweating, fever, chest pain, dilated pupils, and bradycardia or tachycardia. If a hypertensive crisis occurs, immediate medical intervention is necessary to reduce the blood pressure. Strokes (cerebrovascular accidents) and death have been reported.