SIADH and hyponatremia with theophylline.
OBJECTIVE
To report a case of possible theophylline-induced hyponatremia due to the syndrome of inappropriate antidiuretic hormone (SIADH).


METHODS
An 88-year-old man developed severe symptomatic hyponatremia (serum sodium 112 mEq/L) associated with inappropriate natriuresis (urinary sodium 58 mEq/L) temporally related to the initiation of theophylline. The patient fulfilled the criteria for the diagnosis of SIADH after all other causes of hyponatremia were excluded. Furthermore, no other drugs or conditions that could have evoked SIADH were found.


CONCLUSIONS
Theophylline has rarely been associated with hyponatremia. A thiazide-like action of the drug on the stimulation of SIADH could be the underlying mechanism for SIADH.


CONCLUSIONS
Theophylline should be considered as a possible cause of hyponatremia.
Liberopoulos
Evagelos N
EN
Department of Internal Medicine, Medical School, University of Ioannina, Ioannina, Greece.
Alexandridis
George H
GH
Christidis
Dimitris S
DS
Elisaf
Moses S
MS
D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D007010:Hyponatremia / Q000139:chemically induced*; D007177:Inappropriate ADH Syndrome / Q000139:chemically induced*; D008297:Male; D013806:Theophylline / Q000009:adverse effects*
D013806:Theophylline