Lithium-induced diabetes insipidus: Pathophysiology and treatment

Amiloride has the most supporting evidence in the treatment of Li-NDI. A potassium-sparing diuretic, amiloride works by blocking the ENaC in the distal and collecting duct. Blocking the ENaC inhibits uptake of lithium into the principal cells of the collecting duct within the kidney. Research has shown that amiloride can be effective in treating existing Li-NDI, but there is a lack of evidence supporting its preventative effects.¹

Thiazide diuretics work by blocking the sodium-chloride cotransporter in the distal tubules of the kidney. They also upregulate the AQP2 water channels.¹ Research has shown that sodium replacement counteracts the antidiuretic effect of thiazide diuretics; limitations in dietary sodium intake may be necessary for treatment efficacy.¹

Within the kidneys, PGE2 inhibits adenyl cyclase and diminishes water permeability.¹⁰ This causes water to be excreted in urine rather than be reabsorbed.¹⁰ Indomethacin blocks PGE2 activity and increases water reabsorption in the collecting ducts, and sodium reabsorption in the thick ascending loop of Henle.¹⁰ This mechanism can lead to increased lithium reabsorption, which may precipitate toxicity. Research has shown increases in lithium levels by as much as 59% in addition to the risk of causing acute renal failure, especially in older adults.¹⁰ Due to these risks, indomethacin should not be considered a first-line treatment for Li-NDI.

Overall, several medications have shown benefits in the treatment of Li-NDI, with amiloride having the most data. There are currently no medications with sufficient evidence to support prophylactic use.

CASE CONTINUED

Ms. V’s treatment team initiates amiloride 5 mg/d. They increase the dose to 10 mg/d after 2 days, and Ms. V’s hypernatremia resolves as her serum sodium normalizes to 142 mEq/L. Her urinary output also decreases to <3 L/d. Throughout treatment, Ms. V continues taking lithium carbonate to prevent destabilization of her BDI. The team subsequently discharges her, and she has been stable for the past 6 months.

Related Resources

• Andreasen A, Ellingrod V. Lithium-induced diabetes insipidus: prevention and management. Current Psychiatry. 2013;12(7):42-45.
• Zhang P, Gandhi H, Kassis N. Lithium-induced nephropathy; one medication with multiple side effects: a case report. BMC Nephrol. 2022;23(1):309. doi:10.1186/s12882-022-02934-0

Drug Brand Names

Amiloride • Midamor
Desmopressin • DDAVP
Hydrochlorothiazide • Microzide
Indomethacin • Indocin, Tivorbex
Lithium • Eskalith, Lithobid