Antidepressants PDF

NCM 235 Drugs Acting on the central and peripheral nervous system Symptoms of Depression: Intense feelings of sadness, hopelessness, and despair Inability to experience pleasure in usual pleasurable activities Change in sleep patterns Suicidal thoughts Mania is characterized by: E...

NCM 235 Drugs Acting on the central and peripheral nervous system Symptoms of Depression: Intense feelings of sadness, hopelessness, and despair Inability to experience pleasure in usual pleasurable activities Change in sleep patterns Suicidal thoughts Mania is characterized by: Enthusiasm Rapid thought and speech pattern Extreme self confidence and impaired judgment Depression may be secondary to: Organic problems like hypothyroidism, dementia, and anemia Psychiatric problems like schizophrenia, drug abuse, anxiety disorders Use of depressant drugs such as alcohol  Biogenic Amine Theory of Depression Depression results from a deficiency of biogenic amines in key areas of the brain; these biogenic amines include norepinephrine (NE), dopamine, and serotonin (5HT). Mania is caused by overproduction of these neurotransmitters  Biogenic Amine Theory of Depression Both NE and 5HT are released throughout the brain by neurons that react with multiple receptors to regulate arousal, alertness, attention, moods, appetite, and sensory processing. Depression is due to inhibition or deficiencies of functional activity of one or more brain amines  Antidepressants First Generation: Tricyclic Antidepressants (TCAs) Monoamine Oxidase Inhibitors (MAOIs) Second Generation: Selective Serotonin Reuptake Inhibitors (SSRIs)  MAO Inhibitors were initially used to treat other diseases. The antidepressant effect was discovered as an unexpected side effect of the therapy. They were then used to treat depressed patients until TCAs became available in the 1960s. SSRIs have largely replaced TCAs and MAOIs as the drug of choice in treating depression  Selective Serotonin Reuptake Inhibitors (SSRIs) Serotonin is a neurotransmitter makes the person happy  Decrease serotonin: person becomes sad and could lead to depression  Increase serotonin: antidepressant First of choice in treating depression Treatment for anxiety disorders: OCD, PTSD, and panic disorder, eating disorder, enuresis Example of SSRIs fluoxetine (Prozac) paroxetine (Paxil), sertraline (Zoloft), citalopram (Celexa), escitalopram (Lexapro)  Indicated for the treatment of depression, Obsessive-Compulsive Disorder (OCDs), panic attacks, bulimia, posttraumatic stress disorders, social phobias, and social anxiety disorders. Effects not seen for 10-21 days but it will take up to 4 weeks Relief not immediate therefore should not be discontinued prematurely Taken in the morning Can be taken with food  Nursing Implementation 1. Arrange for lower dose in elderly patients and in those with renal or hepatic impairment 2. Monitor the patient for up to 4 weeks 3. Establish suicide precautions for severely depressed patients and limit the quantity of the drug dispensed 4. Administer the drug once a day in the morning 5. Suggest that the patient use barrier contraceptives 6. Provide comfort measures  Tricyclic Antidepressant (TCAs) Examples: imipramine Hydrochloride (Tofranil) amitriptyline (Elavil) amoxapin (Asendin) clomipramine (Anafranil) sinequan (Doxepin) Action: Inhibit the uptake of biogenic amines (norepinephrine and/or serotonin). Action: Elevate mood, improve mental alertness, increase physical activity, and reduce morbid preoccupation in 50-70% of individuals with major depression Treatment of depression associated with organic illness and addiction Amoxapine has neuroleptic effects Amitriptyline should be taken at bedtime to decrease daytime drowsiness Clomipramine has been approved for treatment of OCD  Therapeutic effects may only be evident after 2 – 3 weeks of intake Antihypertensive effects of guanethidine and clonidine may be blocked when used with TCAs May cause daytime sedation, urinary retention, or constipation Check BP, it causes hypotension, Check the heart rate, it causes cardiac arrhythmias Best given after meals Contraindications: Alcohol intake Dementia Suicidal clients ( toxic in overdose) Cardiac disease Multiple concominant medications ( TCA drug indications) Tricyclic antidepressants are only effective when MAOIs don’t work.  Monoamine Oxidase Inhibitors (MAOIs) Examples: Tranylcypromine (Parnate) Phenelzine (Nadril) Isocarboxazid (Marplan) Action: MAOIs increases the concentration of biogenic amines (dopamine, norepinephrine, epinephrine, and serotonin) Effects: Reduces atypical depression ( with weight gain and hypersomnia) or refractory depression in compliant patients Adverse effects: Liver toxicity GI effects: nausea, vomiting, diarrhea or constipation, anorexia, weight gain, dry mouth, and abdominal pain Urinary retention, dysuria, incontinence, and changes in sexual function may also occur Adverse Effects: CV effects: orthostatic hypotension, arrhythmias, palpitations, angina, and the potentially fatal hypertensive crisis if taken with foods containing tyramine ( amino acids) or sympathomimetic Symptoms: occipital headache, stiff neck, flushing, palpitations, diaphoresis, and nausea Contraindications: 1. Pheochromocytoma because the sudden increases in NE levels could result in severe hypertension and CV emergencies 2. CV disease, including hypertension, coronary artery disease, angina, and congestive heart failure, which could be exacerbated by increased NE levels; and known abnormal CNS vessels or defects because the potential increase in blood pressure and vasoconstriction associated with higher NE levels could precipitate a stroke 3. History of headaches Drug interactions: Potentially fatal with  Other MAOIs  SSRIs – serotonin syndrome  meperidine ( Demerol)  buspirone (Buspar)  Dextromethorpan  General anesthetics Hypoglycemic effects of insulin and oral hypoglycemics drugs may be enhanced by MAOIs, and dosages may require adjustment. Teaching: Avoid foods with tyramine: (cheese, liver, avocados, figs, anchovies, yeast extract, deli meats, herring, beer, red wine, ale, chocolate, protein extracts, and stimulants, diet pills, cold and decongestant medications, nasal spray) Never combine with SSRI Concurrent use of MAOI and large amounts of caffeine-containing products like coffee, tea, cola, and chocolate can cause hypertension and cardiac dsyrhythmias.  Nursing Implementation 1. Limit drug access to a potentially suicidal patient 2. Monitor the patient for 2 to 4 weeks 3. Monitor blood pressure and orthostatic blood pressure carefully 4. Monitor liver function before and periodically during therapy 5. Discontinue drug and monitor the patient carefully at any complaint of severe headache 6. Have phentolamine or another adrenergic blocker on standby  Nursing Implementation 7. Avoid tyramine containing food 8. Inform client that MAOIs can increase appetite; and adequate sleep 9. Best taken after meals. Not given in the evening because of their psychomotor stimulating effect, which may produce insomnia 10. There should be at least a two week interval when shifting from one antidepressant to another 11. It takes 2 – 3 weeks before initial therapeutic effects become noticeable lithium carbonate (Lithobid, Lithonate, Eskalith) It inhibits the release of norepinephrine and dopamine but not serotonin, from stimulated neurons Used in treating bipolar affective disorder by stabilizing mood and treating acute mania The only mood stabilizer with data on suicide reduction in bipolar patients  Daily dosage: 900 - 3,600 mg Effectiveness: will take 2-3 weeks Side effects: excessive thirst, metallic like taste, increase urination, dry mouth Check kidney (blood level) before administration of Lithium such as BUN, CREA, electrolytes  Adverse Effect associated with lithium are directly related to serum levels of the drug.  Serum levels of 2.5 mEq/L: Complex multiorgan toxicity, with a significant risk of death. Management: Propranolol for hand tremors Fluid intake of 2-3 liters/day Management: Balanced diet with normal sodium intake (at least 3 gm/day)  Sodium level in the blood should be between 135-145 mEq/L in order to hold water  The relationship between lithium and sodium is that they are inversely proportional. If lithium increases then sodium is decreased and vice versa Management: Have monthly blood levels drawn 12 hours after last dose (maintain therapeutic levels between 0.6–1.2 mEq/L) Mannitol is administered if toxicity occurs Antipsychotic is administered during the first two weeks to manage the acute symptoms of mania until lithium takes effect Other mood stabilizers: 1. Anticonvulsants  valproic acid (Depakote, Depakene)  lamotrigine (Lamistal)  carbamazepine (Tegretol) 2. Antipsychotic  olanzapine (Zyprexa)  risperidone (Risperdal)  quetiapine (Seroquel)