Melt (Desmopressin)

Desmopressin acts on the antidiuretic hormone pathway to manage disorders of water balance and coagulation.

• Central diabetes insipidus: reduces excessive urine output by increasing water reabsorption in the kidneys.
• Nocturnal enuresis: decreases nighttime bedwetting episodes by concentrating urine.
• Hemophilia A: raises plasma factor VIII levels to improve clot formation.
• von Willebrand disease: enhances release of von Willebrand factor to support hemostasis.

• Desmopressin is a synthetic analogue of the natural hormone vasopressin. It selectively binds to V2 receptors located on the basolateral membrane of renal collecting‑duct cells, stimulating cyclic AMP production and promoting insertion of aquaporin‑2 water channels. This increases water reabsorption, concentrating urine. In addition, V2‑receptor activation on endothelial cells enhances the release of coagulation factor VIII and von Willebrand factor, supporting hemostasis.

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

Common Side Effects

• Headache: mild to moderate headache may occur shortly after dosing.
• Nausea: occasional nausea or upset stomach is reported.
• Facial flushing: transient redness of the face can be experienced.
• Mild hyponatremia: slight reduction in serum sodium may be observed, especially with high fluid intake.

Serious or Rare Side Effects

• Severe hyponatremia with seizures: marked drop in sodium can cause seizures or altered mental status.
• Water intoxication: excessive water retention may lead to pulmonary or cerebral edema.
• Thromboembolic events: rare clot formation has been reported in susceptible patients.
• Allergic reactions: anaphylaxis or severe skin rash may occur in hypersensitive individuals.

When prescribing Melt, several safety considerations should be observed.

• Assess serum sodium before initiating therapy: baseline measurement helps identify hyponatremia risk.
• Limit fluid intake during treatment: advise patients to avoid excessive drinking.
• Monitor for signs of water overload: watch for weight gain, edema, or confusion.
• Use cautiously in renal impairment: reduced clearance may increase adverse effect risk.
• Pregnancy and lactation: safety not established; prescribe only if benefit outweighs potential risk.
• Store at ambient temperature: keep below 25 °C, retain original packaging, protect from moisture.

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

Major Interactions (Avoid)

• Carbamazepine: induces hepatic enzymes that reduce desmopressin plasma levels.
• Thiazide diuretics: potentiate antidiuretic effect and increase hyponatremia risk.
• Other antidiuretic agents (e.g., vasopressin analogues): combined use can cause water intoxication.

Moderate Interactions (Monitor Closely)

• NSAIDs: may enhance renal water reabsorption, raising hyponatremia potential.
• SSRIs: additive effect on serum sodium, requiring periodic monitoring.
• ACE inhibitors: can affect blood pressure and electrolyte balance, necessitating observation.