Minirin Melt (Desmopressin)

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

• Central diabetes insipidus: reduces excessive urine production and helps maintain normal fluid balance.
• Nocturnal enuresis: decreases nighttime urine output, reducing bedwetting episodes.
• Mild hemophilia A: raises plasma factor VIII levels to improve clotting.
• Von Willebrand disease type 1: increases von Willebrand factor release, enhancing platelet adhesion.

• Desmopressin is a selective V2‑receptor agonist. By binding to V2 receptors on the renal collecting‑duct cells, it stimulates cyclic AMP formation, which promotes insertion of aquaporin‑2 water channels into the apical membrane, increasing water reabsorption and concentrating urine. In vascular endothelium it triggers release of stored von Willebrand factor and factor VIII. The effect is dose‑dependent and lasts several hours, allowing once‑ or twice‑daily dosing in most indications.

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

Common Side Effects

• Headache: mild to moderate intensity.
• Dry mouth: sensation of oral dryness.
• Nausea: occasional gastrointestinal upset.
• Hyponatremia: mild reduction in blood sodium, usually asymptomatic.
• Flushing: transient warmth or redness.

Serious or Rare Side Effects

• Severe hyponatremia: can lead to seizures or coma.
• Water intoxication: rapid weight gain and edema.
• Allergic reactions: rash, itching, or anaphylaxis.

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

• Assess fluid balance: monitor patient’s fluid intake and output.
• Check serum sodium: baseline and periodic testing, especially in elderly or low‑salt diets.
• Avoid concomitant ADH antagonists: drugs such as conivaptan may counteract effect.
• Use caution in renal impairment: dose adjustment may be required.
• Limit use in patients with uncontrolled hypertension or heart failure: risk of fluid overload.
• Store at ambient temperature: keep below 25 °C in original packaging, protect from moisture.

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

Major Interactions (Avoid)

• Carbamazepine or phenytoin: may increase clearance, reducing effect.
• Loop diuretics (e.g., furosemide): can exacerbate hyponatremia.
• NSAIDs (e.g., ibuprofen): may potentiate water retention and hyponatremia.

Moderate Interactions (Monitor Closely)

• SSRIs or SNRIs: additive risk of hyponatremia.
• Antidiabetic drugs: fluid shifts may affect glucose control.
• Alcohol: may enhance hypotensive effect.