Antidepressants - Overview and Patient Education

Introduction to Antidepressant Medications

This section provides an exhaustive overview of the different classes of antidepressants, their characteristics, effective usage, and important patient education considerations for different medication classes.

Main Classes of Antidepressants

  • Tricyclic Antidepressants (TCA)
      - Members:
        - Imipramine
        - Desipramine
        - Clomipramine
        - Amitriptyline
        - Protriptyline
        - Doxepin
        - Dosulepin
        - Opipramol
      - Targets:
        - Nonspecific
        - Inhibitors of serotonin transporter and noradrenaline transporter
        - Anti-serotoninergic effects, D2R blockers, anti-cholinergic, anti-adrenergic, and anti-histaminic actions
        - Sigma receptor agonists/antagonists

  • Selective Serotonin Reuptake Inhibitors (SSRI)
      - Members:
        - Citalopram
        - Escitalopram
        - Fluoxetine
        - Fluvoxamine
        - Paroxetine
        - Sertraline
      - Targets:
        - Mainly serotonin transporter inhibitors
        - Sigma receptor agonists/antagonists

  • Selective Serotonin and Noradrenaline Reuptake Inhibitors (SSNRI)
      - Members:
        - Atomoxetine
        - Desvenlafaxine
        - Duloxetine
        - Levomilnacipran
        - Milnacipran
        - Sibutramine
        - Tramadol
        - Venlafaxine
      - Targets:
        - Serotonin and noradrenaline transporter inhibitors

  • Monoamine Oxidase Inhibitors (MAOI)
      - Members:
        - Isocarboxazid
        - Tranylcypromine
        - Moclobemide
        - Toloxatone
        - Rasagiline
        - Selegiline
      - Targets:
        - Reversible or irreversible inhibition of MAO-A and MAO-B

  • Selective Noradrenaline Reuptake Inhibitors (SNRI)
      - Members:
        - Reboxetine
        - Viloxazine
        - Maprotiline
      - Targets:
        - Inhibition of noradrenaline transporter

  • Selective Noradrenaline and Dopamine Reuptake Inhibitors (SNDRI)
      - Members:
        - Amineptine
        - Bupropion
        - Dexmethylphenidate
        - Methylphenidate
        - Phenylpiracetam
      - Targets:
        - Inhibition of noradrenaline and dopamine transporters

  • Melatonin Receptor Agonists
      - Members:
        - Ramelteon
        - Agomelatine
        - Tasimelteon
      - Targets:
        - Activation of melatonin receptors

Serotonin Syndrome

  • Definition:
      - Overstimulation of serotonin receptors due to antidepressant use.

  • Onset:
      - Symptoms typically appear within several hours of initiating a new drug or increasing the dosage.

  • Causes:
      - May result from the use of multiple antidepressants, additive medications that change serotonin levels, or excessively high starting doses.

  • Symptoms:
      - Agitation or restlessness
      - Confusion
      - Rapid heart rate
      - High blood pressure
      - Dilated pupils
      - Muscle incoordination, twitching, or rigidity
      - Heavy sweating
      - Diarrhea
      - Headache
      - Shivering
      - Severe symptoms may include:
        - High fever
        - Seizures
        - Cardiac conduction abnormalities
        - Loss of consciousness

  • Treatment for mild to moderate cases:
      - Discontinuation of serotonergic agents
      - Administration of Cyproheptadine, 4 to 8 mg orally, which takes effect within 30 minutes and may need repetition if symptoms persist.

Antidepressants: Selective Serotonin Reuptake Inhibitors (SSRI)

  • Overview:
      - SSRI class is the most commonly used type of antidepressant.

  • Common Side Effects (SE):
      - Gastrointestinal symptoms
      - Anorgasmia
      - Low sexual drive
      - Headaches
      - Weight gain
      - Note: Younger patients have an elevated risk of suicide.
      - Side effects typically wane over time, with the worst experienced in the first two weeks.
      - Administration Advice:
      - Gradual onboarding is recommended (start with half dose for 1-2 weeks, then increase to full dose).
      - Rare side effects include increased bleeding and potential for mania with bipolar disorder.

  • Common SSRIs:
      - Sertraline (Zoloft)
      - Escitalopram (Lexapro)
      - Paroxetine (Paxil)
      - Citalopram (Celexa)
      - Fluoxetine (Prozac)

Antidepressants: Serotonin-Norepinephrine Reuptake Inhibitors (SNRI)

  • Examples:
      - Venlafaxine (Effexor)
      - Duloxetine (Cymbalta)

  • Indications:
      - Classified as second-line drugs.

  • Common SE:
      - Similar to those observed with SSRIs.

  • Patient Education:
      - Similar to that of SSRI use.

Antidepressants: Tricyclic Antidepressants (TCA)

  • Examples:
      - Amitriptyline
      - Doxepin
      - Nortriptyline

  • Considerations Before Administration:
      - Monitor blood pressure (BP) and heart rate (HR)
      - Perform an EKG assessment
      - Be aware of drug interactions (e.g., St. John's Wort, alcohol, benzodiazepines, opioids, antihistamines).

  • Patient Education:
      - Be aware of common side effects such as anticholinergic effects (e.g., orthostatic hypotension).
      - Sedation, which generally resolves after a few weeks.
      - Warning signs of toxicity like dysrhythmia, agitation, and confusion must be recognized.
      - Avoid pregnancy.

Antidepressants: Monoamine Oxidase Inhibitors (MAOI)

  • Pre-Administration Considerations:
      - Loss of consciousness (LOC)
      - Blood pressure (BP) monitoring
      - Identifying comorbidities (diabetes, seizure disorders)
      - Assess for adhesive allergy if used transdermally
      - Must be held for 10-14 days before surgery when replacing other antidepressants.

  • Patient Education:
      - Monitor BP due to the risk of hypertensive crisis and tachycardia.
      - Rotate topical application sites and keep the area clean and dry.
      - Avoid use during pregnancy and refrain from consuming tyramine-rich foods (e.g., aged cheeses, cured meats, tofu, raisins, nuts, alcohol).
      - Watch for cardiac dysrhythmias as a sign of toxicity.
      - Administration at bedtime is advised to mitigate sedation.

Additional Information on Antidepressants

  • Vilazodone:
      - Should not be used with SSRIs/SNRIs; stop MAOIs at least 14 days prior to starting.
      - Grapefruit juice must be avoided and should be taken with food.

  • Mirtazapine:
      - Known for its effect on sleeplessness (worsens with alcohol or benzodiazepines) and is advised at bedtime.

  • Reboxetine:
      - Associated with anticholinergic effects and weight gain; does not induce sleepiness and should not be used with MAOIs.

  • Trazodone:
      - Used primarily for sleep now; virtually never prescribed as a first-line antidepressant.

References

  • ATI. (2019). RN Pharmacology Edition 8.0.

  • Ignatavicius, D. D., Workman, M. L., & Rebar, C. R. (2018). Medical-Surgical Nursing: Concepts for Interprofessional Collaborative Care (9th ed.). St. Louis, MO: Elsevier.

  • Tabloski, P. A. (2019). Gerontological Nursing (4th ed.). New Jersey: Pearson Prentice Hall.