Should lithium be restarted in a patient with a history of lithium use, presenting with psychosis, delusions, and no sleep, who refuses lab tests to confirm current lithium levels?

Do Not Restart Lithium Without Laboratory Confirmation

You should not restart lithium in this patient who refuses laboratory testing, as the FDA explicitly contraindicates lithium use when serum monitoring cannot be performed, and the risk of unrecognized toxicity in this scenario could be fatal. 1

Critical Safety Considerations

FDA Contraindications Apply Here

The FDA drug label is unequivocal: lithium therapy requires "accessibility of facilities to conduct prompt and accurate serum lithium determinations" before initiating therapy. 1 This patient's refusal of lab work creates an absolute barrier to safe lithium administration because:

• Lithium toxicity occurs at doses close to therapeutic concentrations 2, 3
• Without baseline renal function testing, you cannot assess if the patient has developed renal impairment during their time off lithium, which would dramatically increase toxicity risk 4, 1
• You cannot determine if the patient is already lithium toxic from recent undisclosed use, which could explain the current presentation 5

The Clinical Presentation May Be Lithium Toxicity

Psychosis, agitation, and confusion are cardinal features of lithium neurotoxicity. 1, 5 Without knowing:

• Current serum lithium level
• Whether the patient actually stopped taking lithium
• Current renal function
• Hydration status

You risk converting moderate toxicity into severe, potentially irreversible neurological damage by adding more lithium. 1, 5, 6

Alternative Management Strategy

Immediate Steps

• Treat the acute psychosis with antipsychotic medication that does not require serum monitoring 2
• Assess for medical causes of psychosis including infection, metabolic derangement, and substance use through history and physical examination focused on vital signs, neurological exam, and signs of systemic illness 2
• Consider involuntary laboratory testing if the patient meets criteria for emergency psychiatric hold and lacks capacity to refuse medically necessary testing 2

If Laboratory Testing Becomes Available

Only if the patient consents to or you obtain labs through legal means:

• Check serum lithium level immediately to rule out toxicity 3, 4
• Obtain renal function (BUN, creatinine), electrolytes, and thyroid function before any lithium restart 4, 1
• If lithium level is zero and renal function normal, then lithium could be considered as part of long-term management after acute stabilization 2, 3

Long-Term Considerations

While lithium remains effective for mood disorders and may reduce suicide risk 2, 3, its narrow therapeutic window and requirement for regular monitoring make it inappropriate for patients who refuse laboratory testing. 1, 5 Consider alternative mood stabilizers (valproate, carbamazepine, lamotrigine) that have wider therapeutic windows if the patient continues to refuse monitoring. 6

Common Pitfalls to Avoid

• Never assume the patient stopped taking lithium based on history alone - medication non-adherence reporting is notoriously unreliable, and patients may be taking lithium sporadically 5
• Do not rely on clinical assessment alone to rule out lithium toxicity - early toxicity symptoms (tremor, confusion, agitation) overlap completely with primary psychiatric symptoms 1
• Avoid the trap of "therapeutic urgency" overriding safety protocols - the FDA contraindication exists because deaths have occurred from lithium toxicity in monitored patients, let alone unmonitored ones 1, 5