Version July 2025
AVP-R: arginine vasopressin resistance; eGFR: estimated glomerular filtration rate; NSAIDS: nonsteroidal antiinflammatory drugs.
* In some patients, the benefits of continued lithium therapy on mood stabilization outweigh the risks, despite the presence of AVP-R.
¶ The effect of amiloride should be apparent after 2 weeks. Thus, we reassess symptoms at that time, and measure electrolytes and creatinine. If the patient is agreeable, a 24-hour urine should be obtained for volume, urine sodium, urine potassium, and urine osmolality.
Δ There is no specific definition for severe symptomatic polyuria. However, it generally refers to repeated awakening at night to urinate and drink fluids, and a 24-hour urine volume >4 L. Measurement of the 24-hour urine volume is useful in the management of these patients, although it is cumbersome for patients to perform, particularly in those with pronounced polyuria.
◊ Lithium levels may increase (and the dose may need to be decreased) with treatments that can reduce the extracellular fluid volume (such as a low-sodium diet, amiloride, thiazide diuretic, or acetazolamide) and also with treatments that can impair kidney function (such as indomethacin or other NSAIDs). Thus, when these interventions are initiated or titrated, the plasma lithium should be measured twice weekly until stable (usually 2 to 3 weeks).
§ The effect of thiazide diuretics should be apparent in 2 weeks. Thus, 2 weeks after initiation of a thiazide and after each dose increase, we reassess symptoms, measure serum electrolytes and creatinine and, if the patient is agreeable, obtain a 24-hour urine to measure volume, urine potassium, urine sodium, and urine osmolality.
¥ Indomethacin should be avoided in patients with eGFR <45 mL/min/1.73 m2 or hyperkalemia. Otherwise, the choice of agent depends upon clinician and patient preference, such as whether the patient prefers an oral or intranasal medication. If indomethacin is used, the typical dose is 75 mg orally once daily, titrated as needed to 75 mg orally twice daily. If desmopressin is used, the typical dose is 2.5 mcg intranasally at bedtime, titrated as needed to 20 mcg intranasally twice daily. The effect of these medications should be apparent within 2 weeks. Thus, 2 weeks after initiation or dose escalation, the patient should be reassessed for symptoms and have serum electrolytes and creatinine measured; if they are agreeable, a 24-hour urine should be obtained for volume, urine sodium, urine potassium, and urine osmolality.