Desmopressin Acetate film-coated tablets are indicated as antidiuretic replacement therapy for the management of central diabetes insipidus and for temporary polyuria and polydipsia following head trauma or surgery involving the pituitary region. These tablets are not effective in nephrogenic diabetes insipidus.

Desmopressin Acetate sublingual tablets are indicated for the treatment of:

• Primary nocturnal enuresis
• Nocturia
• Central diabetes insipidus

Desmopressin acts by mimicking the effects of endogenous antidiuretic hormone (ADH). It selectively stimulates V2 receptors in the renal collecting ducts, resulting in increased water reabsorption and reduced urine production. Desmopressin has greater potency than natural ADH in increasing plasma factor VIII activity in patients with hemophilia and Type I von Willebrand disease, while showing significantly less pressor activity. Intranasal desmopressin produces approximately one-tenth of the antidiuretic effect of an equivalent injectable dose.

When desmopressin binds to V2 receptors located in the distal tubules and collecting ducts of the nephron, adenylate cyclase is activated. This initiates intracellular signaling pathways that increase the insertion of aquaporin water channels into the luminal membrane, thereby enhancing water permeability and promoting water retention.

Sublingual tablet

• Treatment of diabetes insipidus: Dosage is individual in diabetes insipidus but the total daily sublingual dose normally lies in the range of 120 micrograms to 720 micrograms. A suitable starting dose in adults and children is 60 micrograms three times daily, administered sublingually. This dosage regimen should then be adjusted according to the patient's response. For the majority of patients, the maintenance dose is 60 micrograms to 120 micrograms sublingually three times daily.
• Post-hypophysectomy polyuria/polydipsia: The dose of Desmopressin Acetate Melt should be controlled by measurement of urine osmolality.

Film coated tablet

• Adults and Children: It is recommended that patients be started on doses of 0.05 mg (1/2 of the 0.1 mg tablet) two times a day and individually adjusted to their optimum therapeutic dose. Most patients in clinical trials found that the optimal dosage range is 0.1 mg to 0.8 mg daily, administered in divided doses. Each dose should be separately adjusted for an adequate diurnal rhythm of water turnover. Total daily dosage should be increased or decreased in the range of 0.1 mg to 1.2 mg divided into two or three daily doses as needed to obtain adequate antidiuresis.
• Geriatric Use: This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

Although desmopressin acetate has minimal pressor activity compared with its antidiuretic effect, high doses should be used cautiously with other pressor agents and under careful patient monitoring. Concomitant use of medications that increase the risk of water intoxication and hyponatremia should be approached with caution. These include tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), chlorpromazine, opioid analgesics, NSAIDs, lamotrigine, and carbamazepine.

Desmopressin Acetate Tablets are contraindicated in patients with hypersensitivity to desmopressin acetate or any component of the formulation. It is also contraindicated in patients with moderate to severe renal impairment (creatinine clearance below 50 mL/min), existing hyponatremia, or a history of hyponatremia.

Large doses of intranasal desmopressin formulations or injections may occasionally cause transient headache, nausea, flushing, and mild abdominal cramps. These symptoms generally improve after dose reduction.

There are no adequate controlled studies in breastfeeding mothers. Therefore, desmopressin acetate should be used cautiously during lactation.

Very rare cases of hyponatremia have been reported during postmarketing use of desmopressin acetate. As a potent antidiuretic agent, desmopressin may cause water intoxication and severe hyponatremia, which can be life-threatening if not properly diagnosed and treated. Fluid restriction is therefore recommended and should be discussed with the patient or caregiver. Careful medical supervision is essential.

High-dose intranasal desmopressin and injectable forms have occasionally caused slight elevations in blood pressure, which usually resolve after reducing the dose. Although this effect has not been observed with single oral doses up to 0.6 mg, caution is advised in patients with coronary artery disease or hypertensive cardiovascular disorders because of the potential risk of increased blood pressure.

Synthetic analogue of ADH

Store below 30°C in a dry place. Protect from light and moisture.