HYPONATRAEMIA – HOW TO MANAGE THE SODIUM IMBALANCE?

Desmopressin and hyponatraemia

Desmopressin, a vasopressin analogue, reduces the amount of water excreted by the kidneys by increasing water reabsorption in the distal tubules of the kidneys.^1,2 As a result, serum sodium levels are diluted as water re-enters the circulation.² This can cause hyponatraemia (serum sodium concentration less than 135 mmol/L).^2,3 NICE guidelines grade the severity of hyponatraemia in adults according to serum sodium concentration:³

Further factors that can increase risk of hyponatraemia include:

Age: Elderly patients (65 years of age and older) have a higher risk due to age-related alterations in fluid and electrolyte balance caused by increased sensitivity to vasopressin and decreased renin-angiotensin pathway activity⁴

Gender: Women are at higher risk of developing hyponatraemia than men; this is believed to be due to increased sensitivity of the distal tubules to vasopressin and its analogues^1,4

Medications: Therapies such as diuretics and anti-epileptic agents can cause hyponatraemia*⁴

Previous use of high-dosage desmopressin has been associated with hyponatraemia⁴

*Drugs that may contribute to hyponatraemia should be stopped if appropriate and serum sodium levels should he checked after two weeks.³

Noqdirna: Simple gender-specific dosing leads to lower incidence of hyponatraemia¹

Noqdirna is the only licensed treatment for symptomatic relief of nocturia caused by idiopathic nocturnal polyuria.¹

It is a low-dose desmopressin formulation available as a gender-specific dose, which minimises the risk of hyponatraemia, especially in women and the elderly.¹

Patients over the age of 65 require sodium monitoring at the following three checkpoints – at treatment initiation, after 4-8 days of treatment and at one month.¹

Noqdirna: Simple sodium monitoring at 3 checkpoints for your patients over 65¹

Noqdirna patients with hyponatraemia: the next step

If your patient’s serum sodium levels fall below the lower limit of normal (135 mmol/L), Noqdirna should be discontinued.^1,3 NICE guidelines recommend re-checking serum sodium levels after two weeks.³ When restarting treatment with Noqdirna, serum sodium levels should be monitored and fluid restriction enforced.¹

Our leaflet which gives further information on the benefits of Noqdirna and its simple serum sodium monitoring requirements is downloadable here