Lithium level above 1.5 mEq/L, or confusion, coarse tremor, ataxia, or seizures — hold the dose and notify the provider immediately.
Before you read
Test yourself first: 5 questions
Question 1 of 5
A client on lithium carbonate for bipolar disorder has a serum lithium level of 2.1 mEq/L. Which assessment finding requires immediate nursing action?
Answer: B. The therapeutic range for lithium is approximately 0.6 to 1.2 mEq/L. A level of 2.1 mEq/L indicates toxicity. Coarse hand tremors, severe diarrhea, vomiting, ataxia, and confusion are signs of lithium toxicity and require holding the drug and notifying the provider.
Question 2 of 5
A nurse is teaching a client beginning lithium therapy. Which instruction is most important for preventing lithium toxicity?
Answer: C. Lithium is reabsorbed in the kidney like sodium. Dehydration or low sodium intake increases lithium reabsorption and can cause toxicity. Clients should maintain consistent sodium intake and adequate fluids (about 2 to 3 liters per day) and avoid sudden changes.
Question 3 of 5
A nurse is preparing to administer medications. For which client should the nurse question giving the scheduled lithium dose?
Answer: B. Lithium should be held and the provider notified when the level is toxic or when conditions promote toxicity. A client with a serum lithium of 1.8 mEq/L plus vomiting, slurred speech, and ataxia shows toxicity, so the dose should be questioned. A level of 0.8 mEq/L with no symptoms is therapeutic and the dose can be given.
Question 4 of 5
A client receiving lithium has developed polyuria and increased thirst. The nurse understands this reflects which effect of lithium on the kidneys?
Answer: B. Lithium can interfere with the kidney's response to antidiuretic hormone, causing nephrogenic diabetes insipidus, which produces polyuria and polydipsia. Renal function should be monitored, and the client should maintain adequate hydration.
Question 5 of 5
A client taking lithium reports new onset of vomiting and diarrhea from a stomach virus. Which instruction is most important for the nurse to give?
Answer: B. Sodium and fluid loss (vomiting, diarrhea, sweating, low-sodium diet) increases lithium reabsorption and can cause toxicity. The client should maintain adequate fluid and salt intake and contact the provider, as a lithium level may be needed. Restricting fluids or sodium would worsen toxicity.
Keep the streak going with more questions like these, each with a full rationale.
What is lithium toxicity?
The therapeutic window is narrow (about 0.6–1.2 mEq/L), so small shifts matter. The kidneys handle lithium like sodium: when the body is short on sodium or water, as with dehydration, vomiting, diarrhea, heavy sweating, a low-salt diet, or thiazide diuretics, lithium builds up and the level climbs. Early toxicity looks like GI upset and fine tremor. Severe toxicity causes confusion, seizures, and dysrhythmias and can be fatal. There is no antidote.
Key points to remember
- Therapeutic level about 0.6–1.2 mEq/L; toxicity begins above 1.5 mEq/L and is severe above 2.0 mEq/L.
- Early or mild toxicity: nausea, vomiting, diarrhea, fine hand tremor, polyuria, and thirst.
- Moderate to severe toxicity: coarse tremor, confusion, ataxia, slurred speech, hyperreflexia, seizures, and dysrhythmias.
- Low sodium or dehydration raises lithium; adequate, steady sodium and fluid intake keeps it stable.
- Thiazide diuretics, NSAIDs, and ACE inhibitors raise lithium levels.
- Vomiting, diarrhea, fever, and heavy sweating can raise the level quickly.
- Treatment is supportive; hemodialysis is used for severe toxicity. Lithium can also cause hypothyroidism.
Signs & symptoms
- Early: N/V, tremor, diarrhea
- Late: ataxia, slurred speech, seizures
- Confusion, coarse tremor
Nursing priorities
- Hold the dose and notify the provider for a level above 1.5 mEq/L or any sign of toxicity, because more lithium will worsen it.
- Assess every shift for tremor type, GI symptoms, neurologic changes, and dehydration, because the shift from fine to coarse tremor and new confusion mark worsening toxicity.
- Keep fluid intake steady at about 2–3 L/day and dietary sodium stable, because sodium or water loss raises lithium.
- Monitor lithium level, sodium, creatinine and BUN, and TSH as ordered, because kidney function controls lithium clearance and thyroid function can drop.
- Review every new medication for NSAIDs, thiazides, and ACE inhibitors, because they raise lithium.
- Prepare for supportive care or hemodialysis in severe toxicity.
Labs & values
Worked example
- Cue: A client on lithium has had several days of vomiting and diarrhea and now has a coarse hand tremor and slurred speech.
- Meaning: Fluid and sodium loss has raised the lithium level; these are signs of moderate toxicity.
- Action: Hold the dose, notify the provider, draw lithium, sodium, and creatinine levels as ordered, and start seizure and fall precautions.
- Evaluation: With supportive care the level returns to 0.6–1.2 mEq/L, the tremor eases, and the client can explain why steady fluid and salt intake matter.
Patient teaching
- Drink 2–3 liters of fluid a day and keep your salt intake the same each day. Do not start a low-salt diet.
- Get your lithium blood level checked on schedule.
- Call your provider for vomiting, diarrhea, heavy sweating, a shaky hand tremor that gets worse, confusion, or unsteady walking.
- Avoid NSAIDs such as ibuprofen, and tell every provider you take lithium before starting a new medicine.
Memory tricks
- Lithium follows sodium: when salt or water goes down, lithium goes up.
- 1.5 = hold and call; 2.0 = severe.
Common mistakes
- Encouraging a low-sodium diet. Less sodium means a higher lithium level.
- Calling coarse tremor or confusion a routine side effect. These signal moderate to severe toxicity.
- Giving the next scheduled dose while a high level or toxicity signs are being reported.
- Missing over-the-counter ibuprofen on the medication history.
Red flags: report now
- Lithium level above 1.5 mEq/L, or confusion, coarse tremor, ataxia, or seizures — hold the dose and notify the provider immediately.
- Level above 2.0 mEq/L — severe toxicity; anticipate emergency care and possible hemodialysis.
- Vomiting, diarrhea, fever, or heavy sweating — report and expect a lithium level to be drawn.
- A new thiazide, NSAID, ACE inhibitor, or low-sodium diet order — clarify with the provider and plan closer level monitoring.
References
Clinical references for this topic
