Lithium-induced nephrogenic diabetes insipidus in older people.
METHODS
We report two patients. The first is a 68-year-old woman who presented with a 2-day history of vomiting. She was hypernatraemic and her elevated serum sodium concentration did not improve initially, despite adequate fluid replacement. She subsequently developed polyuria and polydipsia. The second patient, a 77-year-old woman, presented with delirium and severe hypernatraemia after being treated for a chest infection 1 week earlier. Both patients were on long-term lithium treatment.


METHODS
In both the cases, a supervised water-deprivation test done after normalization of the blood biochemistry showed partial nephrogenic diabetes insipidus.


RESULTS
Lithium was discontinued.


CONCLUSIONS
Older people on lithium-especially those requiring supportive care-are at risk of severe hypernatraemia after an acute illness or if their fluid intake is restricted.
Mukhopadhyay
D
D
Department of Integrated Medicine, Withybush General Hospital, Haverfordwest SA61 2PZ, UK.
Gokulkrishnan
L
L
Mohanaruban
K
K
D000368:Aged; D018500:Diabetes Insipidus, Nephrogenic / Q000139:chemically induced* / Q000628:therapy; D005260:Female; D006801:Humans; D008094:Lithium / Q000009:adverse effects* / Q000627:therapeutic use
D008094:Lithium