A 34-year-old woman arrives with a half-empty water bottle, dry lips, and coarse tremor in both hands. Her husband says she has had diarrhea for two days and now “cannot walk straight”; she takes lithium for bipolar disorder but insists she has not taken extra pills. She is sleepy but answers slowly, and the next dose sits unopened in her purse. The question is how much neurologic injury has already occurred—and whether waiting for a level will cost her the chance to recover.

— What’s your move? Read on.

Before you read
  • Why can a “therapeutic” lithium level still be dangerous?
  • What is the fastest safe way to enhance lithium elimination?

When to Think of It

New tremor, ataxia, dysarthria, confusion, myoclonus, vomiting, diarrhea, polyuria, or seizures in a lithium user—especially after dehydration, renal decline, dose escalation, sustained-release ingestion, or interacting drugs.

Sick or Not Sick

The key call is neurologic toxicity plus impaired clearance: does this patient need urgent hemodialysis? Treat the patient’s clinical state, renal function, trajectory, and formulation—not a single lithium concentration.

The First Fifteen Minutes

  • Any altered mental status, seizure risk, hypotension, or dysrhythmia: cardiac monitor, glucose, temperature, IV access, ECG, airway readiness; these detect rapidly reversible threats and lithium-associated conduction abnormalities.
  • Volume depletion or hypotension: 0.9% saline 1–2 L IV, reassessing lungs, perfusion, and urine output; isotonic fluid restores renal perfusion and lithium clearance.
  • Persistent hypoperfusion after fluids: norepinephrine 0.05–0.1 mcg/kg/min IV infusion, titrated to MAP; vasoconstriction supports perfusion when fluids are insufficient.
  • Active seizure or severe agitation: lorazepam 2–4 mg IV, repeat every 5–10 minutes as needed; benzodiazepines suppress lithium-associated neuronal hyperexcitability. (Use IM dosing if no IV access.)
  • Suspected acute sustained-release or massive ingestion with an intact airway: polyethylene glycol-electrolyte solution 1.5–2 L/hour PO/NG until rectal effluent is clear, with toxicology consultation; whole-bowel irrigation removes unabsorbed tablets. Do not use activated charcoal—it does not meaningfully bind lithium.
  • Send serial lithium concentrations, BMP/creatinine, glucose, magnesium, calcium, and ECG; obtain levels every 2–4 hours until clearly falling.

Definitive Care & Disposition

Call medical toxicology and nephrology early. EXTRIP-supported dialysis indications include severe neurologic findings (decreased consciousness, seizures, life-threatening dysrhythmia) regardless of level; impaired renal function with lithium >4 mEq/L; or a level >5 mEq/L, and consideration when the level is >2.5 mEq/L with confusion, treatment-resistant toxicity, or an expected time to fall below 1 mEq/L exceeding 36 hours. Intermittent hemodialysis is preferred; rebound occurs from tissue redistribution, so repeat levels and consider repeat dialysis. Admit symptomatic patients to ICU; even apparently well patients need observation with serial levels after acute ingestion.

How This One Kills

The classic failure is discharging a patient because the first lithium level is “not that high,” while delayed absorption or renal failure allows the level to rise and neurologic injury to progress.
The Differential — What Else Looks Like This
  • Serotonin syndrome — clonus and hyperreflexia with serotonergic exposure; confusing it with lithium toxicity delays removal and antidotal management.
  • Valproate toxicity — hyperammonemic encephalopathy and CNS depression; dialysis thresholds and clearance differ.
  • Anticholinergic toxicity — dry skin, mydriasis, urinary retention, delirium; treating with fluids alone misses a potentially lethal co-ingestion.
  • Uremic encephalopathy — severe renal dysfunction with metabolic abnormalities; both conditions may coexist and require dialysis.

The Second-Day Story

Older adults may present with falls, new tremor, anorexia, or confusion rather than dramatic vomiting. Chronic toxicity can produce severe cerebellar findings at only modest serum concentrations, while acute ingestion may show a high level with initially limited symptoms because tissue distribution is incomplete. Ask about recent diarrhea, NSAIDs, ACE inhibitors, ARBs, and thiazides, and repeat the level rather than relying on a single result.
Back to Our Patient
Back to our 34-year-old: her tremor, ataxia, diarrhea, and reduced alertness make lithium toxicity immediately recognizable, and dehydration has likely reduced renal clearance. After airway readiness, ECG monitoring, isotonic saline, serial lithium levels, and renal studies, her lithium is 4.1 mEq/L with creatinine elevation and worsening dysarthria—she meets criteria for urgent hemodialysis despite not having seized. Toxicology and nephrology arrange intermittent dialysis, with repeat levels to detect rebound; she is admitted to the ICU rather than observed on a ward.
Patient Presentation to Attending
How you’d present this patient on the floor — tight, pertinent positives and negatives, no rambling
“This is a 34-year-old woman with bipolar disorder presenting with two days of diarrhea followed by progressive tremor, ataxia, and slowed mentation. She takes lithium and denies an intentional overdose, but has likely become volume depleted; she has no fever, clonus, rigidity, or anticholinergic findings. She is sleepy but protecting her airway, with coarse tremor and dysarthria, and ECG monitoring is in place. Her lithium is 4.1 mEq/L with acute kidney injury, and repeat testing is pending to define the trend. My assessment is clinically significant lithium toxicity with impaired clearance, and I plan isotonic saline, seizure precautions, serial levels and electrolytes, toxicology and nephrology consultation, and urgent hemodialysis with ICU admission.”

Study Directive

  • Memorize the EXTRIP dialysis triggers and recite them without notes.
  • Draw a lithium-toxicology algorithm from ingestion history → serial levels → dialysis decision.
  • Review your local whole-bowel irrigation and hemodialysis protocols.
  • Practice presenting a lithium-toxic patient in five sentences, explicitly stating why the patient is or is not a dialysis candidate.