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 analogues1,4
- 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 be 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
Download this leaflet which gives further information on the benefits of Noqdirna and its simple serum sodium monitoring requirements.
Prescribing Information and Adverse Event Reporting
Adverse events should be reported. Reporting forms and information can be found at www.mhra.gov.uk/yellowcard.
Adverse events should also be reported to Ferring Pharmaceuticals Ltd.
Tel: 0844 931 0050, Email: firstname.lastname@example.org