Should lithium (lithium carbonate) therapy be held in an adult patient with a history of bipolar disorder and a lithium level of hyperlithemia (1.4 mEq/L)?

Should Lithium Be Held at a Level of 1.4 mEq/L?

Yes, lithium must be held immediately at a level of 1.4 mEq/L, as this represents toxicity requiring urgent clinical assessment and management. 1

Critical Safety Threshold

• A lithium level of 1.4 mEq/L exceeds the therapeutic range for both acute treatment (0.8-1.2 mEq/L) and maintenance therapy (0.6-1.0 mEq/L), placing the patient at significant risk for lithium toxicity 2, 3
• The FDA explicitly warns that lithium toxicity risk is very high in patients with compromised renal function, dehydration, or sodium depletion—conditions that must be immediately assessed at this level 1

Immediate Clinical Actions Required

• Hold all lithium doses immediately until the clinical situation is clarified and lithium level decreases to safe range 1

• Assess the patient urgently for signs of lithium toxicity, including:

  • Coarse tremor (versus fine tremor at therapeutic levels) 2
  • Confusion or altered mental status 2
  • Ataxia or gait disturbance 2
  • Nausea, vomiting, or diarrhea (more severe than mild GI effects) 2
  • Polyuria or signs of dehydration 4

• Check renal function (BUN, creatinine), electrolytes (particularly sodium), and hydration status immediately, as these factors dramatically affect lithium clearance and toxicity risk 3

• Verify the timing of the blood draw—lithium levels should be measured 12 hours post-dose for twice-daily dosing or 24 hours post-dose for once-daily sustained-release preparations 5

Understanding the Level

• If the sample was drawn at an incorrect time (e.g., 12 hours after an evening dose of once-daily lithium), the level may be falsely elevated by approximately 1.3 times the true trough level 5
• However, even accounting for timing errors, a level of 1.4 mEq/L suggests the patient is receiving too much lithium or has developed impaired clearance 3

When to Resume Lithium

• Do not resume lithium until:

  • The repeat lithium level (drawn at correct timing) is below 1.2 mEq/L 2, 3
  • Renal function is verified as stable 3
  • Any contributing factors (dehydration, drug interactions, dietary sodium changes) are identified and corrected 3
  • The patient is asymptomatic for lithium toxicity 2

• When restarting, reduce the lithium dose by 150-300 mg and recheck the level in 5-7 days 4, 3

Common Pitfalls to Avoid

• Never continue lithium at the same dose when the level exceeds 1.2 mEq/L, even if the patient appears asymptomatic—toxicity can progress rapidly 1
• Do not assume the elevated level is a laboratory error without repeating it, but hold the medication while awaiting confirmation 3
• Avoid restarting lithium based on outdated levels, as kidney function, hydration status, and drug interactions can change dramatically over time 3
• Never increase monitoring frequency to "watch closely" while continuing the same dose—the dose must be reduced or held 3

Long-Term Considerations

• Lithium remains the gold standard for bipolar disorder with superior long-term outcomes, including an 8.6-fold reduction in suicide attempts and 9-fold reduction in completed suicides 2, 6
• After this episode, ensure twice-weekly lithium level monitoring during restabilization until therapeutic levels are consistently achieved, then every 3-6 months with renal and thyroid function 3
• Educate the patient and family on early signs of toxicity and the critical importance of maintaining adequate hydration and stable sodium intake 2, 4