SSRIs

Summary

SSRIs include the drugs fluvoxamine, fluoxetine, paroxetine, citalopram, escitalopram, and sertraline. 

SSRIs stands for selective serotonin reuptake inhibitors, meaning they inhibit the reuptake of serotonin in the brain. This increases serotonin activity, but the full effects are delayed and may take 4-8 weeks before any clinical effect is noticed.

SSRIs are used to treat a variety of conditions, including depression, anxiety, PTSD, panic disorder, OCD, and bulimia.

They can cause side effects such as dizziness, nausea and vomiting, sexual dysfunction, insomnia, drowsiness, dry mouth, and headache. Because they alter serotonin levels, SSRIs can cause serotonin syndrome. They may also increase the risk of suicide during the first few weeks of treatment. Another common side effect is weight gain.

SSRIs can interact with other drugs, so it's important to avoid combining them with MAO inhibitors, St. John's Wort, and alcohol.

If stopping an SSRI, it must not be stopped abruptly, and instead tapered down gradually under medical supervision. SSRIs are often best taken in the morning to reduce the side effect of insomnia.

Key Points

• Selective Serotonin Reuptake Inhibitors (SSRIs)
  • Drug Names
    • Paroxetine (Paxil, Pexeva)
    • Sertraline (Zoloft)
    • Citalopram (Celexa)
    • Escitalopram (Lexapro)
    • Fluoxetine (Prozac)
    • Fluvoxamine (Lovox)
  • Mechanism
    • Inhibit reuptake of serotonin
      • Allows more serotonin to remain in the synaptic cleft
    • Intended effects may take 4-6 weeks
      • The patient may feel discouraged if their symptoms aren’t improving right away. Encourage them to continue taking the drug for several weeks for the intended effect to occur.
  • Clinical Use
    • Depression
      • First line treatment for depression, due to its less severe side effects and relative safety compared to other antidepressants
    • Anxiety
      • Panic disorders
      • Generalized anxiety disorder (GAD)
      • Social anxiety
    • Obsessive Compulsive Disorder (OCD)
    • Bulimia
    • Post-Traumatic Stress Disorder (PTSD)
  • Side Effects
    • Increased suicide risk
      • Most common within the first few weeks of treatment
      • The patient may begin to have more energy, without improvement in mood. This puts them at a higher risk of suicide.
    • Weight gain
      • Often seen with long-term use
    • Sexual dysfunction
      • Extremely common side effect
      • Often presents as decreased libido or erectile dysfunction
    • Insomnia
      • SSRIs often cause CNS stimulation, making it hard to sleep
    • Serotonin syndrome
      • Can be thought of as a “serotonin overdose” - there is too much serotonin in the synaptic cleft
      • Manifestations include fever, diaphoresis (sweating), tachycardia, tremors, altered mental status, GI distress, and muscle rigidity or spasms
    • Nausea/vomiting
    • Drowsiness
      • While it’s more common to cause insomnia, SSRIs may cause drowsiness in some patients
      • The patient should not drive until they are aware of how the medication affects them personally
    • Dizziness
      • Instruct patients to change positions slowly
    • Dry mouth
      • Can be mitigated by chewing sugarless gum
      • Encourage patient to have good oral hygiene
    • Headache
  • Interactions
    • Avoid MAOIs
      • Increases risk for serotonin syndrome
    • Avoid St John’s Wort
      • Increases risk for serotonin syndrome
    • Avoid alcohol
  • Administration
    • Do not stop abruptly
      • The drug must be tapered off over time to prevent withdrawal symptoms
      • Withdrawal symptoms include sensory disturbances, GI upset, and insomnia
    • Take in the morning
      • If the patient is experiencing insomnia from the medication, taking it in the morning can help mitigate this side effect