What is the appropriate treatment for lithium-induced diabetes insipidus?

Lithium-induced diabetes insipidus is primarily a nephrogenic diabetes insipidus, which occurs due to the interference of lithium with the action of antidiuretic hormone (ADH) in the kidneys. In this condition, the kidneys are unable to concentrate urine effectively, leading to polyuria and subsequent thirst.

Amiloride is the appropriate treatment for lithium-induced diabetes insipidus because it acts as a potassium-sparing diuretic that specifically inhibits the entry of lithium into renal tubular cells. This mechanism helps to reverse the lithium's effects on the kidneys and promotes better water reabsorption, thus mitigating the symptoms of diabetes insipidus. Unlike other diuretics, amiloride does not cause significant potassium loss, which is an additional benefit for patients who may already be experiencing electrolyte imbalances due to excessive urination.

The other options do not effectively address the underlying issue related to lithium's action on the kidneys. Desmopressin, for instance, is beneficial in central diabetes insipidus by mimicking ADH but does not have an effect on nephrogenic diabetes insipidus caused by lithium. Hydrochlorothiazide has been used in some cases to reduce urine output, but it is not as effective as