Nocutil Melt (Desmopressin)

Desmopressin is a synthetic vasopressin analog used to manage disorders of water balance and certain bleeding disorders.

• Central diabetes insipidus: reduces polyuria by enhancing water reabsorption in the renal collecting ducts.
• Nocturnal enuresis: decreases nighttime bladder emptying episodes by concentrating urine.
• Hemophilia A: raises plasma factor VIII levels to improve clot formation.
• Von Willebrand disease: elevates von Willebrand factor, helping control mucosal bleeding.

• Desmopressin 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. In endothelial cells, V2‑receptor activation triggers release of stored factor VIII and von Willebrand factor, augmenting haemostatic activity.

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

Common Side Effects

• Hyponatremia: mild reduction in serum sodium.
• Headache: transient cranial discomfort.
• Nausea: occasional gastrointestinal upset.
• Facial flushing: brief reddening of the skin.

Serious or Rare Side Effects

• Severe hyponatremia: can cause confusion, seizures, or coma.
• Water intoxication: excessive fluid retention leading to edema.
• Allergic reaction: rash, itching, or swelling.

When prescribing desmopressin, clinicians should observe several precautionary measures to minimize risk.

• Assess renal function: evaluate kidney performance before initiating therapy.
• Monitor serum sodium: check electrolytes regularly, especially in patients at risk of hyponatremia.
• Limit fluid intake: advise patients to restrict excessive water consumption while on treatment.
• Use with caution in elderly: older adults have higher susceptibility to water retention and electrolyte imbalance.
• Avoid concomitant hyponatremia‑inducing drugs: review medication list for diuretics or SSRIs.
• Store at ambient temperature: keep below 25 °C, retain in original packaging, protect from moisture.

Desmopressin can interact with several medicines that affect water balance or its antidiuretic effect.

Major Interactions (Avoid)

• Concomitant use with carbamazepine: may reduce desmopressin efficacy.
• Co‑administration with thiazide diuretics: increases risk of hyponatremia.
• Combination with selective serotonin reuptake inhibitors (SSRIs): potentiates hyponatremia.

Moderate Interactions (Monitor Closely)

• NSAIDs: may enhance antidiuretic effect, requiring sodium monitoring.
• Anticonvulsants such as phenobarbital: may lower plasma levels of desmopressin.