Nokdirna (Desmopressin)

Desmopressin is used in disorders of water balance and certain coagulation deficiencies.

• Central diabetes insipidus: reduces excessive urine production by enhancing renal water reabsorption.
• Primary nocturnal enuresis: decreases nighttime bedwetting episodes through antidiuretic action.
• Bleeding disorders (e.g., mild hemophilia A, von Willebrand disease): raises plasma levels of clotting factors to improve hemostasis.

• Desmopressin is a synthetic analogue of vasopressin that selectively binds to V2 receptors on the basolateral membrane of renal collecting‑duct cells. This activates adenylate cyclase, increasing cyclic AMP, which promotes insertion of aquaporin‑2 channels into the apical membrane, enhancing water reabsorption and concentrating urine. In haemostatic use, it triggers release of von Willebrand factor and factor VIII from endothelial stores.

Desmopressin may be associated with a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Headache: mild to moderate intensity.
• Nasal congestion or irritation: may occur despite sublingual administration.
• Nausea or abdominal discomfort.
• Hyponatraemia: mild electrolyte disturbance.
• Flushing or warmth sensation.

Serious or Rare Side Effects

• Severe hyponatraemia with seizures or coma.
• Water intoxication leading to cerebral oedema.
• Allergic reactions such as rash, itching, or anaphylaxis.
• Thrombotic events in predisposed patients.
• Cardiac arrhythmias due to electrolyte shifts.

When prescribing Desmopressin, clinicians should consider several safety measures to minimise risk.

• Assess fluid balance: monitor intake and output to avoid water overload.
• Evaluate serum sodium: check baseline and periodic levels, especially in the elderly.
• Caution in renal impairment: dose adjustment may be required.
• Avoid concurrent use with other antidiuretic agents: increases risk of hyponatraemia.
• Limit use in patients with uncontrolled hypertension or heart failure: fluid retention may exacerbate condition.
• Store at room temperature: keep below 25 °C, retain in original packaging, protect from moisture and direct sunlight.

Desmopressin can interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Concomitant use of thiazide diuretics: may potentiate antidiuretic effect and hyponatraemia.
• NSAIDs (e.g., ibuprofen, naproxen): can reduce renal prostaglandin synthesis, increasing risk of water retention.
• Selective serotonin reuptake inhibitors (SSRIs): combined effect may heighten hyponatraemia risk.

Moderate Interactions (Monitor Closely)

• Anticoagulants (e.g., warfarin): Desmopressin may enhance clotting factor levels, affecting anticoagulation monitoring.
• Antihypertensives (e.g., ACE inhibitors): monitor blood pressure as fluid shifts may influence control.
• Alcohol: can exacerbate central nervous system effects and fluid balance.