Selective Serotonin Reuptake Inhibitors (SSRIs)

Psychiatric Drug Introduction

Psychiatric medications can be broken down into the following categories
- antidepressants
- antipsychotics
- bipolar medications
anxiolytics

Overview

Drugs
- fluoxetine
- paroxetine
- sertraline
- citalopram
- fluvoxamine
Mechanism
- serotonin-specific reuptake inhibitors (SSRIs)
- takes 2-3 weeks for antidepressants to have an effect
  - should try for at least 6 weeks
  - prior to this time, persistence of symptoms indicates inadequate trial
Clinical use
- depression
- OCD
- bulimia
- social phobias
Toxicity
- much milder than other depression therapies
- anxiety, agitation, insomnia
- weight gain
- GI distress
- sexual dysfunction (anorgasmia)
- serotonin syndrome
  - diagnose using using the Hunter Serotonin Toxicity Criteria
    - presence of one of the following sets of features
      - spontaneous clonus
      - inducible clonus with agitation or diaphoresis
      - ocular clonus with agitation or diaphoresis
      - tremor and hyperreflexia
      - hypertonia, temperature above 100.4° F (38° C), and ocular or inducible clonus.
  - characterized by autonomic instability (HR changes, sweating, shivering, flushing), mental status changes
  - treatment includes:
    - withdrawal of the offending agent
    - benzodiazepines to treat agitation and tremor
    - cyproheptadine as an antidote
    - neuromuscular paralysis, sedation, and intubation for criticall ill patients
  - risk factors
    - dietary tryptophan
    - concurrent medications
      - anti-depressants, amphetamines, and analgesics