Lithium Overdose

First Things First

  • Metal similar to potassium, magnesium and sodium
  • Currently used in treatment of bipolar disorder for the mania and as a mood stabilizer
  • Narrow toxic-to-therapeutic range ratio
  • Tablets and capsules
    • 300-mg tablets have 8 mEq of lithium
    • Also comes in 150-mg and 600-mg capsules
    • Extended release, 300 mg, 450 mg
    • Syrup has 8 mEq/5 mL.
    • Normal serum level is 0.7-1.2 mEq/L.
  • Mechanism of action is not well understood.
    • May stabilize cell membranes
    • Inhibits NE to interfere with cAMP
    • Enhances effects of serotonin
    • Rapidly absorbed into serum from GI tract and therefore peaks rapidly
    • Syrup: 40 min
    • Rapid release: 2-4 hr
    • Extended release: 4-12 hrs
  • Renal elimination 95%
    • Sweat/saliva/milk: 5%
    • Prolonged & delayed absorption
    • Decreased elimination
    • Intracellular lithium build-up
  • It is not metabolized.
    • No protein binding
    • We reabsorb more when we are in a low-sodium or low-volume state.
  • Lithium modulates signals affecting the cytoskeleton, thereby stabilizing moods.

There's more to see -- the rest of this topic is available only to subscribers.

Last updated: April 28, 2010