Journal of Human Hypertension (2003) 17, 151 & 2003 Nature Publishing Group All rights reserved 0950-9240/03 $25.00 www.nature.com/jhh LETTER TO THE EDITOR Diuretic-induced hyponatraemia in elderly hypertensive women Journal of Human Hypertension there were 10 with plasma so- plasma sodium of 111 mmol/l (2003) 17, 151. doi:10.1038/ dium levels in the range 101– when inadvertently rechallenged sj.jhh.1001513 109 mmol/l. Of the 26, 11 had with thiazides, the agent this time plasma potassium levels less than being hydrochlorothiazide copre- My experience of diuretic- 3.5 mmol/l. The age range was scribed with amiloride. I now induced hyponatraemia in the 74–93 and 22 were women. Hy- utilise torasemide as an adjunc- elderly is in accordance with the drochlorothiazide was the offend- tive diuretic in patients with a observations made by the ing agent in 12 cases, having been previous history of thiazide- authors.1 In my personal series coprescribed with amiloride in induced hyponatraemia. The data of 61 cases of severe hyponatraemia 10 instances, and with triamterene presented here extend the obser- (plasma sodium o120 mmol/l), in two. Bendrofluazide was the vations I published previously on compiled over a period of 18 offending agent in nine instances, this topic. years in patients aged 465, 26 the dose being 2.5 mg/day in were attributable to thiazide seven instances (coprescribed diuretics, culprit drugs in seven with amiloride in one instance), References other cases being frusemide (three and 5.0 mg/day in the other two. 1 Sharabi Y et al. Diuretic induced cases), spironolactone on its own Three cases were attributable to hyponatraemia in elderly hypertensive (one case), nonsteroidal anti- cyclopenthiazide, and one each to women. J Hum Hyperten 2002; 16: inflammatory drugs (two cases), hydroflumethiazide and to inda- 631–635. 2 Jolobe OMP. Torasemide (letter). Proc R carbamazepine, and tricyclic anti- pamide, respectively. One pa- Coll Phys Edinburgh 2000; 30: 178. depressants (one each). Under- tient, aged 80, who had become lying causes in the other 27 cases hyponatraemic (plasma sodium included bronchial and other can- 114 mmol/l), while taking bend- OMP Jolobe cers, chest infection, hypoadrena- rofluazide 2.5 mg/day copre- Department of Adult Medicine, lism, and inappropriate use of scribed with amiloride 5 mg/day, Tameside General Hospital, hypotonic intravenous fluids. reverted to a plasma sodium of Among the 26 with reversible 135 mmol/l after withdrawal of Fountain Street, Ashton under, thiazide-induced hyponatraemia, both agents, only to revert to a Lyne OL6 9RW, UK.