How do you manage polyuria and polydipsia from lithium?

My first step is to confirm that the symptoms, including polydipsia and polyuria, are due to NDI and not other reasons. Other potential causes that should be excluded are:

• Psychogenic polydipsia
• other substance-induced, such as caffeine, diuretics
• primary DM
• pituitary related
• CKD

Lowering the dose...

Amiloride 5 mg will do the trick for most patients. Make sure you are around 0.75, using IR Li, all at night.