Antidepressants and Mood Stabilizers - In Depth Notes

Depression

• Etiology

  • Genetic predisposition
  • Social and environmental factors
  • Biologic conditions

• Pathophysiology theories

  • Decreased levels of monoamine neurotransmitters:
  • Norepinephrine
  • Serotonin
  • Dopamine

• Signs and Symptoms

  • Depressed mood, despair
  • Weight loss or gain
  • Decreased ability to think or concentrate
  • Loss of interest in most activities
  • Fatigue, loss of energy
  • Insomnia or hypersomnia
  • Suicidal thoughts

• Types of Depression

  • Reactive Depression:
  • Sudden onset after precipitating events (e.g., death of a loved one)
  • Usually lasts for months
  • Major Depression:
  • May be primary or secondary to health issues
  • Symptoms include significant loss of interest, difficulty concentrating, sleep disturbances, feelings of worthlessness
  • Bipolar Disorder:
  • Characterized by mood swings between mania and depression

Complementary and Alternative Therapy for Depression

• Herbal Products:
  • Ginkgo biloba and St. John’s wort
  • Discontinue use 1-2 weeks before surgery
  • Consult with a healthcare provider before use

Major Antidepressants

• Classes of Antidepressants:
  • Tricyclic Antidepressants (TCAs)
  • Selective Serotonin Reuptake Inhibitors (SSRIs)
  • Serotonin Norepinephrine Reuptake Inhibitors (SNRIs)
  • Atypical Antidepressants
  • Monoamine Oxidase Inhibitors (MAOIs)

Tricyclic Antidepressants (TCAs)

• Examples: amitriptyline, imipramine, trimipramine, doxepin, desipramine, nortriptyline, protriptyline

• Use: Major depression

• Action:

  • Blocks reuptake of norepinephrine and serotonin
  • Elevates mood, increases interest in daily activities, decreases insomnia
  • Blocks histamine receptors (sedation) and cholinergic receptors (anticholinergic effects)

• Side Effects/Adverse Reactions:

  • Drowsiness, dizziness, blurred vision, sedation
  • Dry mouth/eyes, skin rash, GI distress, constipation
  • Urinary retention, sexual dysfunction
  • Weight gain, seizures, orthostatic hypotension
  • Suicidal ideation, extrapyramidal symptoms (EPS), neuroleptic malignant syndrome (NMS)

• Interactions:

  • Alcohol and CNS depressants increase CNS depression
  • MAOIs can cause toxic psychosis, cardiotoxicity
  • Antithyroid drugs may increase dysrhythmias

Selective Serotonin Reuptake Inhibitors (SSRIs)

• Examples: fluoxetine, fluvoxamine, sertraline, paroxetine, citalopram, escitalopram

• Action: Blocks reuptake of serotonin

• Uses:

  • Major depression
  • Anxiety disorders
  • Obsessive-compulsive disorder
  • Panic disorders, phobias
  • Post-traumatic stress disorder
  • Prevention of migraine headaches, premenstrual tension syndrome, eating disorders, and substance use disorders

• Interactions:

  • Increased sedation with alcohol and other CNS depressants
  • Grapefruit juice can lead to SSRI toxicity

• Side Effects/Adverse Reactions:

  • Headache, insomnia
  • Blurred vision, dry mouth, GI distress
  • Erectile dysfunction, suicidal ideation
  • Side effects typically decrease over 1-4 weeks

Serotonin Norepinephrine Reuptake Inhibitors (SNRIs)

• Examples: duloxetine, levomilnacipran, desvenlafaxine

• Action: Inhibits reuptake of serotonin and norepinephrine

• Uses:

  • Major depression
  • Generalized anxiety disorder
  • Social anxiety disorder

• Side Effects/Adverse Effects:

  • Drowsiness, dizziness, insomnia, blurred vision
  • Headaches, amnesia
  • Erectile/j ejaculatory dysfunction
  • Tachycardia, hypertension
  • Orthostatic hypotension, seizures, NMS, suicidal ideation

Atypical Antidepressants

• Examples: Amoxapine, Maprotiline, Bupropion

• Action: Affects serotonin, norepinephrine, and dopamine neurotransmitters

• Uses:

  • Major depression
  • Reactive depression
  • Anxiety disorders

• Side Effects/Adverse Effects:

  • Dry mouth, blurred vision
  • Orthostatic hypotension, dizziness
  • Drowsiness, palpitations, tachycardia
  • Constipation, erectile/ejaculatory dysfunction

Monoamine Oxidase Inhibitors (MAOIs)

• Examples: tranylcypromine sulfate, isocarboxazid, selegiline HCl, phenelzine sulfate

• Action: Inactivates norepinephrine, dopamine, epinephrine, and serotonin

• Use: Treatment of depression not controlled by TCAs and second-generation antidepressants

• Drug Interactions:

  • CNS stimulants like vasoconstrictors can precipitate a hypertensive crisis
  • Foods containing tyramine (e.g., aged cheeses, certain meats, beer, red wine) can cause hypertensive crisis

• Side Effects/Adverse Effects:

  • Dizziness, drowsiness
  • Peripheral edema, headache
  • Weight gain, insomnia
  • Anticholinergic effects, orthostatic hypotension
  • Risk of hypertensive crisis from tyramine interactions, suicidal ideation

Clinical Judgment: Antidepressant Agents Assessment/Intervention

• Assess for mental status and suicidal ideation
• Observe for signs of depression, mood changes, insomnia, apathy
• Monitor vital signs
• Monitor for drug-drug and food-drug interactions
• Provide list of foods to avoid
• Caution against concurrent use of alcohol or CNS depressants

Mood Stabilizer: Lithium

• Serum Therapeutic Range: 0.8 to 1.2 mEq/L

• Toxicity Risk: Serum levels > 1.5 mEq/L

• Action: Alters ion transport in muscle/nerve cells, increases receptor sensitivity to serotonin

• Use: Primarily for bipolar disorder and manic episodes

• Side Effects/Adverse Reactions:

  • Drowsiness, dizziness, blurred vision, headache
  • Restlessness, tremors
  • Memory impairment, dry mouth, thirst, metallic taste
  • GI distress, weight gain/loss
  • Hypotension, dysrhythmias, peripheral edema, increased urination, dehydration

• Interactions:

  • Increased lithium levels: thiazides, certain antidepressants, NSAIDs
  • Decreased lithium levels: caffeine, loop diuretics

Clinical Judgment: Lithium Assessment/Interventions

• Observe for mood changes, insomnia, suicidal ideation
• Monitor vital signs and lithium levels
• Check sodium levels and cardiac status
• Advise against caffeine and maintain adequate sodium intake
• Assess for anxiety, confusion, coping ability

Practice Questions

• Practice Question #1:

  • True statement about amitriptyline: The drug should be discontinued slowly.

• Practice Question #2:

  • For patients on fluoxetine: Medication may cause headaches and insomnia.

• Practice Question #3:

  • Important assessment for MAOIs: Tyramine food intake.

• Practice Question #4:

  • Important lab test for lithium patients: Serum electrolytes.

• Practice Question #5:

  • Dietary teaching for MAOIs: Avoid cheddar cheese.

• Practice Question #6:

  • Advice about lithium therapy: It may take 1-2 weeks for benefits to appear.