Reactions 1680, p308 - 2 Dec 2017
Hyponatraemia: case report
A 69-year-old man developed hyponatraemia during
treatment with sildenafil [Viagra; route, indication and time to
reaction onset not stated].
The man, who had no history of disease, had been receiving
one tablet of sildenafil 50mg everyday for several months. One
day, after taking sildenafil, he suddenly experienced cramps
for some time and lost conciousness at home, and was
hospitalised. In spite of being haemodynamically stable, he
was confused and losing conciousness on and off (Glasgow
Coma Scale [GCS] score: 9 (E2V2M5)). Brain CT scan and MRI
revealed mild atrophy. Electroencephalography demonstrated
no typical spike-and-wave pattern. Serum sodium level and
serum osmolality were 113 mEq/L and 237 mOsm/kg,
respectively. Antidiuretic hormone and cortisol levels were
2.2 pg/mL and 18.4 µg/dL, respectively. According to the
criteria of Bartter and Schwartz, suspected mechanism of this
severe hyponatraemia might have been by the syndrome of
inappropriate secretion of antidiuretic hormone.
The man received treatment with sodium chloride [saline].
As a result, after 4 days of the hospitalisation, he recovered
from hyponatraemia with serum sodium level returning to
normal. He was responsive with a GCS of 15 (E4V5M6). He
was discharged after 8 days of the the hospitalisation, and
hyponatraemia was suspected to be sildenafil-induced.
Author comment: "First, we must consider the possibility
of severe hyponatraemia occurring in patients taking
sildenafil." "Sildenafil is suspected to have caused the severe
hyponaetremia in this case"
Taguchi H, et al. Severe hyponatremia associated with sildenafil (Viagra). Acute
Medicine and Surgery 2: 223, No. 3, Jul 2015. Available from: URL: http://
doi.org/10.1002/ams2.91 - Japan
Reactions 2 Dec 2017 No. 16800114-9954/17/1680-0001/$14.95 Adis © 2017 Springer International Publishing AG. All rights reserved