Nocdurna (Desmopressin)

Desmopressin acts on the antidiuretic hormone pathway to manage conditions characterized by excessive urine output.

• Central diabetes insipidus: reduces polyuria by enhancing water reabsorption in the kidneys.
• Nocturnal enuresis (bedwetting) in children and adolescents: decreases nighttime urine volume, helping achieve dry nights.
• Mild hemophilia A or von Willebrand disease: raises plasma factor VIII and von Willebrand factor levels to improve clotting.

• Desmopressin is a synthetic analogue of vasopressin that selectively binds to V2 receptors on the basolateral membrane of renal collecting‑duct cells. Receptor activation stimulates adenylate cyclase, increasing intracellular cAMP, which promotes insertion of aquaporin‑2 water channels into the apical membrane, thereby enhancing water reabsorption and concentrating urine.

Desmopressin may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Headache: mild to moderate pain in the head.
• Nausea: feeling of queasiness.
• Nasal congestion: sensation of a blocked nose.

Serious or Rare Side Effects

• Severe hyponatremia: marked sodium depletion that can cause seizures or coma.
• Water intoxication: excessive water retention leading to cerebral edema.
• Allergic reaction: rash, itching, swelling, or anaphylaxis.

When prescribing Desmopressin, several safety considerations should be observed.

• Dose titration: start with the lowest effective dose and adjust based on clinical response.
• Fluid restriction: limit excessive fluid intake to reduce risk of hyponatremia.
• Monitor electrolytes: regularly check serum sodium and osmolality during therapy.
• Renal function: assess kidney function before initiating and during treatment.
• Concomitant ADH‑active drugs: avoid simultaneous use of other antidiuretic agents without supervision.
• Store at ambient temperature: keep below 25°C in the original packaging, protect from moisture and direct sunlight.

Desmopressin can interact with several medication classes, requiring careful management.

Major Interactions (Avoid)

• Other antidiuretic agents (e.g., carbamazepine, chlorpropamide): may cause profound hyponatremia.
• NSAIDs (e.g., ibuprofen, naproxen): can potentiate water retention and hyponatremia.
• Certain antidepressants (e.g., SSRIs, SNRIs): increase risk of hyponatremia.

Moderate Interactions (Monitor Closely)

• Diuretics (especially thiazides): may exacerbate electrolyte disturbances.
• Opioids (e.g., morphine): can enhance antidiuretic effect.
• CYP2C9 substrates: desmopressin is minimally metabolised but monitor for altered levels.