Persistent nephrogenic diabetes insipidus following lithium therapy

Area of Science:

• Nephrology
• Endocrinology
• Neuroscience

Background:

• Lithium is a common treatment for bipolar disorder.
• Lithium can induce nephrogenic diabetes insipidus (NDI), a condition characterized by excessive thirst and urination.
• NDI is typically considered reversible upon lithium discontinuation.

Observation:

• A patient with a history of lithium-induced NDI developed severe hypernatraemic dehydration after a head injury.
• Despite discontinuing lithium therapy ten years prior, the patient exhibited persistent thirst and polyuria.
• Investigations confirmed normal thirst osmoregulation and vasopressin secretion, indicating persistent NDI.

Findings:

• This case demonstrates that lithium-induced NDI can persist for at least ten years after lithium cessation.
• The patient's polyuria persisted despite normal thirst and vasopressin regulation, suggesting a chronic or irreversible renal effect.

Implications:

• The long-term persistence of lithium-induced NDI challenges the assumption of its complete reversibility.
• Understanding the renal mechanisms behind persistent NDI is crucial for effective patient management.
• This case emphasizes the need for long-term monitoring of patients with a history of lithium-induced NDI.