Lithium overdose

Non-reversible lithium neurotoxicity continues to be reported (165,166), including a case of lithium overdose (serum lithium concentration 3.9 mmol/1) with persistent severe ataxia for 9 months that improved markedly when inadvertently treated with high-dose buspirone (120-160 mg/day) (167). 

When the Marseilles Poisons Centre analysed information on lithium overdose between 1991 and 2000, in addition to an unspecified number of suicide attempts and accidental poisonings in children, the next most frequent reports were prescription misinterpretation (n = 43), dehydration in the elderly (n = 35), renal insufficiency (n = 15), and diuretic interactions (n = 8) (533). 

There has been a 10-year review of lithium overdose in 304 patients (544). The circumstances were accidental ingestion, mistakes in the quantity of ingested tablets, raised lithium concentrations due to diuretic therapy, renal insufficiency or dehydration, and suicide attempts. About half the patients required management in an intensive care unit, 5% needed hemodialysis, 10% had cardiac disturbances or neurological complications, and 2% died. The authors concluded that modified-release... 

Hemodialysis (383,552,553), sometimes with additional continuous venovenous hemofiltration dialysis (554,555), continues to be described as a successful intervention for lithium poisoning. Peritoneal dialysis is a far less efficient way to clear lithium from the body. One patient treated in this way had permanent neurological abnormalities and another died a third toxic patient who also had diabetic ketoacidosis died after treatment with hydration and insulin (556). On the other hand, a 51-year-old woman who took 50 slow-release lithium carbonate tablets (450 mg) had a serum lithium concentration of 10.6 mmol/1 13 hours later, but no evidence of neurotoxicity or nephrotoxicity. She was treated conservatively with intravenous fluids and recovered fully (557). Acute lithium overdose is often better tolerated than chronic intoxication. 

A brief review of cases of lithium toxicity has suggested that there is no clinical evidence that gastric lavage is useful in lithium overdose (565). However, an anecdote is of interest, since it suggests that gastric lavage soon after ingestion may be beneficial (566). 

Newland KD, Mycyk MB. Hemodialysis reversal of lithium overdose cardiotoxicity. Am J Emerg Med 2002 20(l) 67-8. 

Roberge RJ, Martin TG, Schneider SM. Use of sodium polystyrene sulfonate in a lithium overdose. Ann Emerg Med 1993 22(12) 1911-5. 

The normal or usual route of elimination is impaired (eg, lithium overdose in a patient with renal failure). 

A single-dose study in 6 subjects given lithium 600 mg ten hours before acetazolamide 500 or 750 mg found a 31% increase in the urinary excretion of lithium. A woman was successfully treated for a lithium overdose... 

Drug overdose Treatment of lithium overdose must be individualized to the chnical condition. Three case reports have highlighted the number of options that are available to clinicians. 

Puhr J, Hack J, Early J, Price W, Meggs W. Lithium overdose with electrocardiogram changes suggesting ischemia. J Med Toxicol 2008 4(3) 170-2. 

Serinken M, Karcioglu O, Korkmaz A. Rarely seen cardiotoxicity of lithium overdose complete heart block. Int J Cardiol 2009 132(2) 276-8. 

Boltan DD, Fenves AZ. Effectiveness of normal saline dieresis in treating lithium overdose. Proc Bayl Univ Med Cent 2008 21(3) 261-3. 

---