Akathisia, Medication-Induced Acute Akathisia

  • Definitions
  1. Akathisia
    1. Motor restlessness or psychomotor aggitation typically as a medication-related Extrapyramidal Side Effect
    2. May present as inability to sit still, pacing or wringing hands
  • Pathophysiology
  1. Decreased Dopaminergic activity in the mesocortical pathway
    1. Mesocortical Pathway originates in the ventral tegmental area
    2. Mesocortical Pathway projects to the Limbic System and prefrontal cortex
  2. Mesocortical pathway typically inhibits motor function
    1. When this pathway is inihibited, unwanted involuntary movement occurs
  3. Other effects
    1. Decreased Dopaminergic activity in ventral tegmental area may increases Serotonin and Norepinephrine activity
  • Symptoms
  1. Tense and ucomfortable Sensation
  2. Timing
    1. Onset may be abrupt with rapid infusion of IV medications (e.g. Compazine, Metoclopramide)
  • Signs
  1. Leg fidgety movement
  2. Pacing
  3. Inability to sit still
  4. Rocking from foot to foot, shifting weight while standing
  • Management
  1. Reduce medication dose or switch to alternative medication
  2. Acute symptomatic management
    1. Beta Blockers
      1. Propranolol 40-80 mg orally daily
    2. Serotonin Antagonists (5HT-2A)
      1. Mirtazapine 15 mg orally daily
      2. Cyproheptadine (Periactin) 8-16 mg orally daily
    3. Benzodiazepines
      1. Clonazepam 0.5 to 1 mg daily to twice daily
      2. Diazepam 5-15 mg orally daily
    4. Anticholinergics
      1. Benztropine (Cogentin) 1-4 mg orally daily
    5. Other agents
      1. Amantadine 100 mg orally daily
      2. Clonidine 0.1 mg orally daily to twice daily
  • Prevention
  1. Infuse Compazine or Metoclopramide over 30 minutes in a bag (e.g. D5W) instead of a bolus over minutes