Recurrent hyponatremia due to tolterodine

A 65-year-old woman came to the endocrinology clinic of our hospital with fatigue, muscle weakness and urinary incontinence. She has had these complaints for five months and was hospitalized at the neurology department and diagnosed with hyponatremia, urge incontinence, hypertension, diabetes mellitus and cerebrovascular disease. Her history included hospitalization for recurrent hyponatremia two times in the last five months; she could not walk due to muscle weakness. Her medications were tolterodine (six months), metformin, amlodipin and insulin aspart 30% and aspart protamin 70% (for three years). On admission, her blood pressure was 130/80 mmHg, pulse rate 80/min and neurological examination revealed left hemiparesis. Laboratory analyses are listed in Table 1. Table 1 Laboratory analyses Ejection fraction was 60% by echocardiography. After 2 liters of saline infusion, her blood sodium level was 126 mmol/L. After discontinuing tolterodine the serum sodium levels returned to normal in a few days. Hyponatremia is a common and important electrolyte abnormality in hospitalized patients causing a wide range of neurological symptoms. The differential diagnosis of hyponatremia is mandatory since there is a risk of neurological sequels during the treatment. Tolterodine-associated hyponatremia is especially seen in the elderly; our case is the fourth case of tolterodine-associated hyponatremia.1,4,5 Drug-induced syndrome of inappropriate antidiuretic hormone secretion (ADH) can occur due to an increase in ADH production centrally or an increased sensitivity to ADH in the nephron.3,5 Tolterodine (Detrol, Detrusitol) is an anti-muscarinic used to treat urinary incontinence. Tolterodine might induce hyponatremia by either increasing the ADH secretion or ADH action.4 Laboratory findings in diagnosis of syndrome of inappropriate ADH include:3 (1) hyponatremia 20 mEq/L; (3) normal serum creatinine; (4) low uric acid; and (5) normal adrenal and thyroid function. Our findings were consistent with syndrome of inappropriate ADH; when we stopped tolterodine, serum sodium levels returned to normal. Urinary incontinence is a common and distressing complaint in the elderly.2 In this report, we wanted to draw attention to a very rare adverse event caused by tolterodine, a drug mostly prescribed for the elderly.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.