Reactions 915 - 17 Aug 2002

STheophylline

Hyponatraemia due to syndrome of inappropriateantidiuretic hormone secretion in an elderly patient:case report

An 88-year-old man developed hyponatraemia due tosyndrome of inappropriate antidiuretic hormone secretionwhile receiving theophylline [therapeutic indication not clearlystated].

The man, who had a history of diabetes and heart failure,was admitted to hospital with a 5-day history of worseningconfusion 10 days after starting theophylline 200mg twicedaily and IV ampicillin for a urinary tract infection. Hisconcomitant medication included furosemide, metformin,finasteride, gliclazide and nitroglycerin. On presentation hewas anxious, was not well oriented to time and place, and hehad mild oedema in his lower extremities. A chest x-rayrevealed an elevated cardiothoracic index and an ECG showedtachyarrhythmia. Laboratory investigations revealed severehyponatraemia (112 mEq/L), hypokalaemia, hypochloraemia,hypomagnesaemia and mild hypophosphataemia. His plasmaand urine osmolalities were 230 and 430 mOsm/kg,respectively, and his plasma antidiuretic hormone level was 10pg/ml (normal 0.5–2).

Theophylline and furosemide were discontinued and theman received IV potassium chloride and magnesium sulfate.His water intake was restricted. Three days later he was alertand his serum electrolytes had returned to normal.Liberopoulos EN, et al. SIADH and hyponatremia with theophylline. Annals ofPharmacotherapy 36: 1180-1182, Jul-Aug 2002 - Greece 800914828

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Reactions 17 Aug 2002 No. 9150114-9954/10/0915-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved