Sir,Chronic lithium therapy impairs urinary concentrating ability in over half of the patients.[12] Cases with severe or disabling polyuria may require clinical attention for better compliance. We discuss a case with successful management of lithium-induced polyuria, raising a few related, pertinent issues.A 24-year-old unmarried female, with bipolar II disorder and hypothyroidism, with a history of three severe, suicidal depressive episodes interspersed with two hypomanic periods, first presented to the outpatient clinic during a third depressive episode in July 2015, warranting admission. She was on lithium (900 mg/day) and aripiprazole (20 mg/day) to which tablet escitalopram was added, with marked improvement in mood and behavior. By October 2015, she was maintaining euthymic on tablet lithium 1200 mg/day (serum levels: 0.74–0.85 mmol/L), along with other medications.By early 2016, she started to have increased frequency of micturition, nocturia, and obligatory thirst. By mid-2016, there were frequent complaints of bed wetting and passing urine in clothes while rushing to the washroom. This led to social embarrassment and distress embarrassed.A stepwise management approach was undertaken (fluid restriction to 2 L/day, shift to the single night time dosage of extended-release tablet) with negligible improvement. The patient was briefly admitted in August 2016 to manage polyuria. On examination, there was obesity (body mass index: 32.46 kg/m2) and euthymic mood. Routine hemogram, serum biochemistry, prolactin and cortisol levels were normal. Nephrology consultation was taken and input-output charting was maintained. Serum osmolality (302 mOsm/kg) was slightly raised, and urine osmolality was (180 mmol/L) was decreased. Twenty-four-hours urinary protein (70 mg/24 h), 24-h urinary creatinine (1000 mg/24 h), urinary sodium/potassium (103/33.4 meq/L), and serum sodium/potassium levels (135/4.1 meq/L) were within normal limits.A possibility of substituting lithium with another mood stabilizer was entertained, however, a history of severe depression and suicidality coupled with good response to lithium was considered as a point against lithium discontinuation at that point of time. Tablet amiloride (5 mg) was planned as a pharmacological management of lithium induced polyuria. In India, unfortunately, it is not available stand-alone drug and is available only in combination with tablet hydrochlorothiazide 50 mg. To ensure safety in view of the combination, as is recommended, the lithium dose was decreased by 30% (from 1200 to 750 mg).A significant reduction in urine volume (from over 5 L to 1.5–1.8 L/day) was noted from 1st week. The patient was discharged in a month with multiple psychoeducation sessions. No significant adverse effects have been reported. The patient is currently in active follow-up for 2 years for her psychiatric condition, with more than 8 months of outpatient department follow-up after control of polyuria.A long-term management review shall include a possible trial of stopping amiloride-thiazide in future and re-assess status of polyuria, review need for substitution/addition of mood stabilizers. A close monitoring for depressive relapses and frequent follow-up visits shall continue.Side-effects like polyuria should be managed with a cautious, stepwise approach, first with various nonpharmacological strategies.[3]Amiloride is a relatively safer option compared to thiazide diuretics, with much less propensity to cause drug-drug interactions and its potassium sparing effects. Consequently, unlike thiazides, it is less likely to increase lithium to toxic range and is not associated with hypokalemia.[345]In a certain small proportion of patients in whom a change of lithium as a mood stabilizer is not feasible or not indicated at least at that point of time, amiloride may be considered as an option.A major issue in the Indian context is the lack of availability of amiloride as a stand-alone drug, without combination with thiazides. Such availability in India will help to expand the range of therapeutic options available for patients with disabling lithium-induced polyuria. This needs to be addressed.