4.1. Therapeutic indications

• Treatment of vasopressin-sensitive cranial diabetes insipidus

• Treatment of post-hypophysectomy polyuria/polydipsia

Desmopressin 120 and 240 micrograms

• Treatment of primary nocturnal enuresis

4.2. Posology and method of administration

Posology

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 in accordance with 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 sublingual tablets should be controlled by measurement of urine osmolality.

Desmopressin 120 and 240 micrograms

Primary nocturnal enuresis The recommended initial dose for children (from 5 years of age) and adults (up to 65 years of age) with normal urine concentrating ability, who have primary nocturnal enuresis, is 120 micrograms at bedtime administered sublingually. If this dose is not sufficiently effective, the dose may be increased up to 240 micrograms, administered sublingually. Fluid restriction should be observed.

Desmopressin sublingual tablets are intended for treatment periods of up to 3 months. The need for continued treatment should be reassessed by means of a period of at least 1 week without Desmopressin sublingual tablets.

In the event of signs or symptoms of water retention and/or hyponatraemia (headache, nausea/vomiting, weight gain, and, in severe cases, convulsions) treatment should be interrupted until the patient has fully recovered. When restarting treatment strict fluid restriction should be enforced (see section 4.4).

If adequate clinical effect is not achieved within 4 weeks following appropriate dose titration the medication should be discontinued.

Special Populations

Elderly patients (65 years of age and older)

The initiation of treatment in patients over 65 years of age is not recommended (see section 4.3 and 4.4).

Renal impairment

Desmopressin sublingual tablets are contraindicated in patients with moderate and severe renal insufficiency (see section 4.3).

Hepatic impairment

No dose adjustment is needed for patients with hepatic impairment (see section 5.2).

Paediatric population

Desmopressin sublingual tablets are indicated for treatment in this population (see section 4.2 above). Dose recommendations are the same as in adults.

Method of administration

Sublingual use, place the tablet under the tongue where it dissolves without the need for water.

Food intake may reduce the intensity and duration of the antidiuretic effect at low doses of desmopressin (see section 4.5).

4.3. Contraindications

• Hypersensitivity to desmopressin or any of the excipients listed in section 6.1

• Known or suspected cardiac insufficiency and other conditions requiring treatment with diuretics. Desmopressin sublingual tablets should only be used in patients with normal blood pressure

• Habitual or psychogenic polydipsia (resulting in a urine production exceeding 40 ml/kg/24 hours) and alcohol abuse

• Desmopressin should not be prescribed to patients over the age of 65

• Moderate and severe renal insufficiency (creatinine clearance below 50 ml/min)

• Known hyponatremia

• Syndrome of inappropriate ADH secretion (SIADH).

Before prescribing desmopressin sublingual tablets, the diagnoses of psychogenic polydipsia and alcohol abuse should be excluded.

4.4. Special warnings and precautions for use

Special warnings

Care should be taken with patients who have reduced renal function and/or cardiovascular disease or cystic fibrosis. In chronic renal disease, the antidiuretic effect of desmopressin would be less than normal.

Safety warnings specific to the treatment of primary nocturnal enuresis:

When desmopressin 120 or 240 microgram sublingual tablets are used for the treatment of enuresis, the fluid intake must be limited to a minimum from 1 hour before until the next morning (at least 8 hours) after administration. Treatment without concomitant reduction of fluid intake may lead to water retention and/or hyponatraemia with or without accompanying warning signs and symptoms (headache, nausea/vomiting, weight gain, and, in severe cases, convulsions). All patients and, when applicable, their guardians should be carefully instructed to adhere to the fluid restrictions.

Precautions

Desmopressin should be used with caution in patients with conditions characterised by fluid and/or electrolyte imbalance.

Precautions must be taken in patients at risk for increased intracranial pressure.

Precautions specific to the treatment of primary nocturnal enuresis:

Severe bladder dysfunction and outlet obstruction should be considered before starting treatment.

Elderly patients and patients with serum sodium levels in the lower range of normal may have an increased risk of hyponatraemia.

Treatment with desmopressin should be interrupted during acute intercurrent illnesses characterised by fluid and/or electrolyte imbalance (such as systemic infections, fever, gastroenteritis).

Precautions to avoid hyponatraemia including careful attention to fluid restriction and more frequent monitoring of serum sodium must be taken in case of concomitant treatment with drugs, which are known to induce SIADH, e.g. tricyclic antidepressants, selective serotonin reuptake inhibitors, chlorpromazine and carbamazepine, case of concomitant treatment with NSAIDs.

Excipients with known effect

Desmopressin sublingual tablets contain lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.

4.5. Interaction with other medicinal products and other forms of interaction

Pharmacodynamic interactions

Substances which are known to induce SIADH e.g. tricyclic antidepressants, selective serotonin reuptake inhibitors, chlorpromazine and carbamazepine, as well as some antidiabetics of the sulfonylurea group particularly chlorpropamide, may cause an additive antidiuretic effect leading to an increased risk of water retention and/or hyponatraemia (see section 4.4).

NSAIDs may induce water retention and/or hyponatraemia.

Pharmacokinetic interactions

Concomitant treatment with loperamide may result in a 3-fold increase in plasma desmopressin concentrations, which may lead to an increased risk of water retention and/or hyponatraemia. Although not investigated, other drugs slowing intestinal transit might have the same effect.

A standardised 27% fat meal significantly decreased the absorption (rate and extent) of a 0.4mg dose of oral desmopressin tablets. Although it did not significantly affect the pharmacodynamic effect (urine production and osmolality), there is the potential for this to occur at lower doses. If a reduction of the effect is noted, then the effect of food should be considered before increasing the dose.

Food intake may reduce the intensity and duration of the antidiuretic effect at low oral doses of desmopressin tablets.

4.6. Fertility, pregnancy and breast-feeding

Pregnancy

Data on a limited number (n=53) of exposed pregnancies in women with diabetes insipidus indicate rare cases of malformations in children treated during pregnancy. To date, no other relevant epidemiological data are available. Animal studies do not indicate direct or indirect harmful effects with respect to pregnancy, embryonal/foetal development, parturition or postnatal development.

Caution should be exercised when prescribing to pregnant women. Blood pressure monitoring is recommended due to the increased risk of pre-eclampsia.

Lactation

Results from analyses of milk from nursing mothers receiving high dose desmopressin (300 micrograms intranasally) indicate that the amounts of desmopressin that may be transferred to the child are considerably less than the amounts required to influence diuresis. Therefore it is not considered necessary to stop breastfeeding.

4.7. Effects on ability to drive and use machines

Desmopressin has no or negligible influence on the ability to drive and use machines.

4.8. Undesirable effects

The most serious adverse reaction with desmopressin is hyponatraemia, which is associated with headache, nausea, vomiting, decreased serum sodium, weight increase, malaise, abdominal pain, muscle cramps, dizziness, confusion, decreased consciousness and in severe cases convulsions and coma.

The cause of the potential hyponatraemia is the anticipated antidiuretic effect. The hyponatraemia is reversible and in children it is often seen to occur in relation to changes in daily routines affecting fluid intake and/or perspiration. In both adults and children special attention should be paid to the precautions addressed in section 4.4

Tabulated summary of adverse reactions

The table below is based on the frequency of adverse drug reactions reported in clinical trials with oral desmopressin conducted in children and adolescents for the treatment of Primary Nocturnal Enuresis (PNE) (N = 1923).

System Organ Class

Common

(≥ 1/100, <1/10)

Uncommon

(≥ 1/1000, <1/100)

Rare

(≥ 1/10000, <1/1000)

Psychiatric disorders

Affect lability

Aggression

Anxiety symptoms

Nightmare

Mood swings

Nervous system disorders

Headache

Somnolence

Vascular disorders

Hypertension

Gastrointestinal disorders

Abdominal pain

Nausea

Vomiting

Diarrhoea

Renal and urinary disorders

Bladder and urethral symptoms

General disorders and administration site conditions

Oedema peripheral

Fatigue

Irritability

In the case of hyponatraemia, the treatment of hyponatraemia should be individualised (see section 4.9).

Caution should be taken when substances with increased risk of water retention are taken concurrently with desmopressin sublingual tablets, since the concurrent use may increase the risk of hyponatraemia (see section 4.4).

Anaphylactic reactions, Psychomotor hyperactivity and some Psychiatric reactions such as abnormal behaviour, emotional disorder, depression, hallucination & insomnia, have not been seen in clinical trials but spontaneous reports have been received.

In children, psychiatric disorders including affect lability, aggression, anxiety, mood swings & nightmare are generally reversed upon treatment discontinuation.

Isolated cases of allergic skin reactions and more severe general allergic reactions have been reported.

Other special populations:

Elderly patients and patients with serum sodium levels in the lower range of normal may have an increased risk of developing hyponatraemia (see section 4.4).

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9. Overdose

Symptoms

An overdose of desmopressin leads to a prolonged duration of action with an increased risk of water retention and/or hyponatraemia

Treatment

Although the treatment of hyponatremia should be individualised, the following general recommendations can be given:

- Hyponatremia is treated by discontinuing the desmopressin treatment and fluid restriction.

- Symptomatic treatment.