(Neurological findings appear late in acute ingestion, but are common presenting complaints in chronic toxicity.)
- QTc prolongation (rare)
- Tremors, fasciculations, or myoclonic jerks
- Nephrogenic Diabetese Insipidus (in chronic toxicity)
- Lithium level
- Therapeutic lithium level is 0.8 – 1.2 mEq/L (mmol/L)
- 1.5-2.5 mEq/L (mmol/L) – mild symptoms, chronic toxicity, tremor, slurred speech, lethargy
- 2.5-3.5 mEq/L (mmol/L) – moderate symptoms, worsening lethargy, tremors, clonus
- > 3.5 mEq/L (mmol/L) – severe toxicity
- Repeat levels every 2-4 hours until trend proven
- Serum lithium levels correlate more closely with symptoms in chronic toxicity due to steady state level in CNS
- Repeat lithium level 6 hours post dialysis as lithium equilibrates, or in sustained release ingestion.
- Complete blood count
- Serum electrolytes / metabolic profile
- Pregnancy test
- Acetaminophen level
- Salicylate level
- Alcohol level
- TSH level (hypo and hyperthyroidism have been reported)
- Oral activated charcoal does not work (Lithium is a charged particle)
- Whole bowel irrigation can be considered in acute large volume sustained release lithium ingestion, if patient is awake and asymptomatic.
- IV hydration and sodium replacement
- Lithium level > 5 mEq/L (mmol/L).
- Lithium level > 4 mEq/L (mmol/L) AND creatinine >2.0 mg/dL
- Lithium level > 2.5 mEq/L (mmol/L) AND severe toxicity with inability to receive large volume IV fluids (ie. CHF)
- Decreased level of consciousness, seizure, encephalopathy, severe dysrhythmia, regardless of level
- Dehydration resulting in kidney injury and reduced excretion
- Intentional or accidental overdose
- angiotensin converting enzyme (ACE) inhibitors
- nonsteroidal antiinflammatory drugs (NSAIDs)
- GI absorption is rapid with peak levels in 1-2 hours for immediate release preparations, up to 6 hours for sustained release.
- Lithium is a small ion with no protein binding
- Steady state reached in 5 days for therapeutic use.
- Half life is 18 hours in adults, up to 36 hours in the elderly.
- Excretion is renal.
- Re-absorption can occur in the kidneys in response to volume depletion.
- Highest tissue levels are found in the brain and kidneys.
- Chronic toxicity can occur from dehydration or alteration in excretion due to kidney injury. Elderly patients are especially susceptible.
- Acid base disorders are not common in lithium toxicity and should prompt testing for salicylate and alcohol ingestion
- Lithium can elevate WBC levels.
- Mcknight RF, Adida M, Budge K, Stockton S, Goodwin GM, Geddes JR. Lithium toxicity profile: a systematic review and meta-analysis. Lancet. 2012;379(9817):721-8. PubMed
- Clendeninn NJ, Pond SM, Kaysen G, et al. Potential pitfalls in the evaluation of the usefulness of hemodialysis for the removal of lithium. J Toxicol Clin Toxicol 1982; 19:341. PubMed
- Lee D, et al. Lithium Toxicity. Medscape 2018; accessed August 2018. Medscape
- Perrone J., et al: Lithium Poisoning. In: UpToDate, Post, TW (Ed), UpToDate, Waltham, MA, 2018. Accessed 08/18