Mitaclau (Desmopressin)

Desmopressin acts on the antidiuretic hormone pathway and is indicated for several endocrine and haemostatic disorders.

• Central diabetes insipidus: reduces excessive urine output by increasing renal water reabsorption.
• Nocturnal enuresis: decreases nighttime bedwetting episodes in children and adults.
• Hemophilia A: raises plasma factor VIII levels to improve clot formation.
• von Willebrand disease: enhances release of von Willebrand factor to support platelet adhesion.

• Desmopressin is a synthetic analogue of vasopressin that selectively binds to V2 receptors on the basolateral membrane of renal collecting‑duct cells. Activation of these G‑protein‑coupled receptors stimulates adenylate cyclase, raising intracellular cAMP and promoting insertion of aquaporin‑2 water channels into the apical membrane, thereby increasing water reabsorption. In endothelial cells, it triggers release of von Willebrand factor and factor VIII, improving haemostatic function.

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

Common Side Effects

• Headache: mild to moderate pain often reported after dosing.
• Nausea: transient gastrointestinal discomfort.
• Hyponatraemia: mild reduction in serum sodium, usually asymptomatic.
• Nasal irritation: when administered intranasally (not typical for sublingual).
• Flushing: brief warmth or redness of the skin.

Serious or Rare Side Effects

• Severe hyponatraemia: can lead to seizures, coma, or death.
• Water intoxication: excessive fluid retention causing cerebral oedema.
• Allergic reactions: rash, pruritus, or anaphylaxis in rare cases.
• Thrombotic events: increased risk in patients with pre‑existing clotting disorders.
• Hypertensive crisis: rare abrupt rise in blood pressure.

Desmopressin requires careful monitoring to minimise risks.

• Monitor serum sodium: check electrolytes regularly, especially in the first days of therapy.
• Adjust dose in renal impairment: reduced clearance may heighten hyponatraemia risk.
• Limit fluid intake: avoid excessive water consumption while on treatment.
• Use caution in the elderly: age‑related renal changes increase susceptibility to adverse effects.
• Store at room temperature: keep in the original pack, protect from moisture and direct sunlight.

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

Major Interactions (Avoid)

• Carbamazepine: induces hepatic enzymes that reduce desmopressin plasma levels.
• Concomitant use with thiazide diuretics: may potentiate water retention and hyponatraemia.
• Concomitant use with other antidiuretic agents: risk of severe hyponatraemia.

Moderate Interactions (Monitor Closely)

• NSAIDs: can blunt renal prostaglandin synthesis, enhancing antidiuretic effect.
• ACE inhibitors or ARBs: may increase risk of low sodium levels.
• Selective serotonin reuptake inhibitors (SSRIs): potential additive effect on water balance.