Minirin
Synthetic Vasopressin Analogue for Diabetes Insipidus and Bedwetting
Quick Facts About Minirin
Key Takeaways About Minirin
- Fluid restriction is critical: You must limit fluid intake from 1 hour before until 8 hours after taking Minirin to prevent dangerous drops in blood sodium (hyponatraemia)
- Effective for bedwetting: Minirin is a first-line treatment for primary nocturnal enuresis in children aged 6 and older, with clinical efficacy demonstrated in large randomised controlled trials
- Sublingual administration: Minirin Melt tablets are placed under the tongue and dissolve without water – do not swallow or chew them
- Monitor sodium levels: Blood sodium should be checked before starting treatment and periodically during therapy, especially in elderly patients and those at risk of hyponatraemia
- Not for everyone: Minirin must not be used in patients with habitual excessive fluid intake (polydipsia), heart failure requiring diuretics, or moderate to severe kidney disease
What Is Minirin and What Is It Used For?
Minirin contains desmopressin, a synthetic version of the body's natural antidiuretic hormone (vasopressin). It is prescribed to treat central diabetes insipidus, primary nocturnal enuresis (bedwetting) in children aged 6 years and older, and nocturia (excessive urination at night) in adults. Minirin works by acting on the kidneys to reduce urine production.
Desmopressin is a structural analogue of arginine vasopressin (AVP), the naturally occurring antidiuretic hormone produced by the posterior pituitary gland. In the healthy body, AVP is released in response to increased blood osmolality or decreased blood volume, and it acts on the kidneys to promote water reabsorption, thereby concentrating the urine and reducing its volume. Desmopressin mimics this natural process but has been chemically modified to have a significantly longer duration of action and to virtually eliminate the vasopressor (blood vessel-constricting) effects that natural vasopressin possesses.
The key structural modifications in desmopressin are deamination of the cysteine residue at position 1 and substitution of L-arginine with D-arginine at position 8. These changes result in a molecule that is highly selective for the vasopressin V2 receptor, which is found primarily in the collecting ducts of the kidneys. By binding to V2 receptors, desmopressin triggers a cascade of intracellular signalling that leads to the insertion of aquaporin-2 water channels into the apical membrane of the collecting duct cells. This dramatically increases the permeability of the collecting ducts to water, allowing water to be reabsorbed from the urine back into the bloodstream, resulting in concentrated, low-volume urine.
In patients with central diabetes insipidus, the pituitary gland fails to produce sufficient quantities of vasopressin, leading to the excretion of large volumes of very dilute urine (polyuria) and consequent excessive thirst (polydipsia). This condition can be caused by damage to the hypothalamus or posterior pituitary from neurosurgery, head trauma, tumours (such as craniopharyngiomas), infiltrative diseases (such as sarcoidosis or Langerhans cell histiocytosis), or may be idiopathic. Without treatment, patients with central diabetes insipidus may produce 3 to 20 litres of urine per day, leading to severe dehydration if fluid intake is not maintained. Minirin effectively replaces the missing vasopressin, restoring normal urine concentration and dramatically improving quality of life.
For primary nocturnal enuresis (bedwetting) in children aged 6 years and older, Minirin is one of the most widely studied and prescribed treatments. Bedwetting affects approximately 15% of five-year-olds and 5% of ten-year-olds, and can have significant psychological and social impacts on children and families. In many children with nocturnal enuresis, overnight urine production exceeds bladder capacity due to insufficient nocturnal vasopressin secretion. By providing exogenous desmopressin at bedtime, Minirin reduces overnight urine production to a volume the bladder can comfortably hold, preventing bedwetting episodes. The National Institute for Health and Care Excellence (NICE) recommends desmopressin as a first-line pharmacological treatment for bedwetting when alarm therapy has not been successful or is not appropriate.
In adults with nocturia (waking two or more times per night to urinate), Minirin can reduce nocturnal urine volume and increase the duration of uninterrupted sleep. Nocturia is a common and often underestimated condition that significantly impairs sleep quality and daytime functioning. It becomes increasingly prevalent with age, affecting up to 60% of adults over 70 years. When nocturia is caused by nocturnal polyuria (overproduction of urine at night), desmopressin can be an effective treatment option. However, the risk of hyponatraemia is higher in elderly patients, particularly those over 65 years, and careful monitoring of serum sodium is mandatory.
Desmopressin was first synthesised in 1966 and has been used clinically since the 1970s. It is included on the World Health Organization's Model List of Essential Medicines for the treatment of diabetes insipidus. Minirin is manufactured by Ferring Pharmaceuticals and is available in multiple formulations worldwide. The sublingual lyophilisate (Minirin Melt) was developed to provide a convenient dosage form that dissolves rapidly under the tongue without water, making it particularly suitable for children and for bedtime administration.
What Should You Know Before Taking Minirin?
Before starting Minirin, your doctor must assess your medical history carefully. Fluid restriction is mandatory during treatment. Minirin is contraindicated in patients with habitual polydipsia, heart failure requiring diuretics, moderate to severe renal insufficiency, and known hyponatraemia. Blood sodium levels must be checked before and during treatment.
Contraindications
You should not take Minirin if any of the following apply to you:
- Allergy to desmopressin or any of the other ingredients in Minirin (gelatin from fish, mannitol, citric acid)
- Habitual or psychogenic polydipsia (compulsive excessive fluid intake exceeding 40 mL/kg/day) – combined with desmopressin this creates an extremely high risk of water intoxication and severe hyponatraemia
- Known or suspected cardiac insufficiency and other conditions requiring treatment with diuretics – the water-retaining effect of desmopressin can worsen heart failure
- Moderate to severe renal insufficiency (creatinine clearance below 50 mL/min) – impaired kidney function increases the risk of fluid overload and hyponatraemia
- Known hyponatraemia – desmopressin would further lower already dangerously low sodium levels
- Syndrome of inappropriate antidiuretic hormone secretion (SIADH) – adding exogenous antidiuretic hormone to an already excessive endogenous secretion is dangerous
Warnings and Precautions
Talk to your doctor or pharmacist before taking Minirin if you have or have had any of the following:
- Conditions affecting fluid or electrolyte balance – including cystic fibrosis, adrenal insufficiency, and conditions predisposing to fluid overload
- Elderly age (over 65 years) – the risk of hyponatraemia is significantly increased in older patients; serum sodium must be monitored before treatment, after dose adjustments, and regularly during ongoing therapy
- Urinary bladder dysfunction or outflow obstruction – reduced urine volume may mask underlying urological conditions
- Risk of raised intracranial pressure – fluid retention can worsen conditions associated with increased intracranial pressure
- Von Willebrand disease type IIB – desmopressin can cause platelet aggregation and transient thrombocytopenia in this specific subtype
Fluid intake must be minimised from 1 hour before administration to at least 8 hours after taking Minirin. During this period, drink only to satisfy genuine thirst and only in small sips. Excessive fluid intake during desmopressin therapy can cause water retention and dangerously low blood sodium levels (hyponatraemia), which may lead to headache, nausea, vomiting, seizures, coma, and in severe cases can be fatal. This warning applies to all indications and all age groups.
Drug Interactions
Several medications can increase the risk of hyponatraemia when taken together with Minirin, either by enhancing its antidiuretic effect or by independently lowering serum sodium levels. Always tell your doctor about all medications you are taking.
| Drug / Class | Type | Effect |
|---|---|---|
| Tricyclic antidepressants (TCAs) | Potentiation of antidiuretic effect | Increased risk of water retention and hyponatraemia; TCAs such as amitriptyline and imipramine may enhance desmopressin's renal effects |
| SSRIs (e.g. sertraline, fluoxetine) | Additive hyponatraemia risk | SSRIs independently cause hyponatraemia via SIADH; combined use significantly increases the risk of dangerously low sodium levels |
| Chlorpromazine | Potentiation of antidiuretic effect | Enhances the effect of desmopressin, increasing the risk of water retention and hyponatraemia |
| Carbamazepine | Potentiation of antidiuretic effect | Carbamazepine has its own antidiuretic properties and can potentiate the effect of desmopressin, substantially increasing the risk of hyponatraemia |
| Sulfonylureas (e.g. glibenclamide) | Potentiation of antidiuretic effect | May enhance desmopressin's antidiuretic effect; chlorpropamide has the strongest documented interaction |
| Loperamide | Increased desmopressin exposure | Loperamide may increase plasma concentrations of desmopressin by up to 3-fold, significantly raising the risk of hyponatraemia |
| NSAIDs (e.g. ibuprofen, naproxen) | Potentiation of antidiuretic effect | NSAIDs impair renal free water clearance and can enhance desmopressin's water-retaining effect, increasing the risk of hyponatraemia |
| Dimethicone (simethicone) | Reduced absorption | May reduce the absorption of desmopressin from the sublingual mucosa, potentially decreasing its effectiveness |
Pregnancy and Breastfeeding
Limited clinical data from pregnant women with diabetes insipidus treated with desmopressin have not indicated any adverse effects on pregnancy or on the health of the unborn or newborn child. Reproductive toxicity studies in animals have not shown harmful effects. However, Minirin should only be used during pregnancy if your doctor considers it clearly necessary. If you are pregnant, think you may be pregnant, or are planning to have a baby, ask your doctor for advice before taking this medicine.
Results from analyses of human breast milk from mothers receiving high-dose desmopressin (300 micrograms intranasally) have shown that the amounts of desmopressin that may be transferred to the breastfed infant are considerably less than the amounts required to influence diuresis. Based on this, desmopressin is generally considered compatible with breastfeeding, but you should inform your doctor if you are breastfeeding.
Effects on Driving and Operating Machinery
Minirin has no known effect on the ability to drive or use machines. However, if you experience side effects such as headache or dizziness, you should exercise caution when driving or operating machinery until the symptoms have resolved.
What Is the Correct Dosage of Minirin?
The dose of Minirin depends on the condition being treated. For diabetes insipidus, the usual starting dose is 60 mcg sublingual three times daily. For bedwetting in children, the starting dose is 120 mcg at bedtime. For nocturia in adults, the starting dose is 60 mcg at bedtime. Always follow your doctor's instructions exactly.
Regardless of the indication, fluid intake must be limited from 1 hour before taking Minirin until at least 8 hours after administration. This is essential to prevent hyponatraemia. When treating bedwetting in children, ensure the child does not drink large amounts of fluid in the evening.
Central Diabetes Insipidus
Adults and Children
Starting dose: 60 mcg sublingual three times daily (one 60 mcg sublingual tablet placed under the tongue three times daily)
Dose adjustment: The dose should be individually adjusted based on the patient's urine output and thirst response. The total daily dose typically ranges from 120 mcg to 720 mcg
Your doctor will find the optimal dose by monitoring your fluid balance, urine output, urine osmolality, and serum sodium. Each patient's dose requirement is different, and careful titration over several days is usually needed.
Primary Nocturnal Enuresis (Children 6 Years and Older)
Children Aged 6 Years and Older
Starting dose: 120 mcg sublingual at bedtime (one 120 mcg sublingual tablet placed under the tongue)
If insufficient response after 1–2 weeks: The dose may be increased to 240 mcg at bedtime
Treatment should be reviewed after 3 months by withdrawing Minirin for at least one week to assess whether the child still needs treatment. Many children naturally outgrow bedwetting, and periodic drug-free intervals help determine if continued treatment is necessary. The child must restrict fluid intake from 1 hour before to 8 hours after taking the tablet.
Nocturia in Adults
Adults Under 65 Years
Starting dose: 60 mcg sublingual at bedtime
If insufficient response after 1 week: The dose may be increased to 120 mcg, and subsequently to 240 mcg
Serum sodium must be measured within 3 days of dose initiation or increase, one week later, one month later, and then at approximately 3-month intervals thereafter.
Adults 65 Years and Older
Starting dose: 60 mcg sublingual at bedtime
Due to the increased risk of hyponatraemia in elderly patients, serum sodium must be measured before treatment starts, within 3 days of initiation, and at more frequent intervals during ongoing therapy. Dose increases should only be made under careful medical supervision.
How to Take Sublingual Tablets (Lyophilisate)
The Minirin sublingual tablet (lyophilisate) should be placed under the tongue, where it dissolves within seconds. Do not swallow the tablet whole. Do not take it with water. Do not chew or crush the tablet. The active ingredient is absorbed through the mucous membrane under the tongue. After placing the tablet under the tongue, wait until it has completely dissolved before swallowing any saliva. Handling: remove the tablet from the blister carefully by peeling back the foil; do not push the tablet through the blister as this may damage the fragile lyophilisate.
Missed Dose
If you forget to take a dose of Minirin, take it as soon as you remember, unless it is close to the time for your next dose. In that case, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a forgotten dose. If you are treating diabetes insipidus and notice that your urine output increases significantly after missing a dose, contact your doctor for advice.
Overdose
An overdose of Minirin leads to prolonged excessive water reabsorption by the kidneys, resulting in water intoxication and severe hyponatraemia (dangerously low blood sodium levels). Symptoms of hyponatraemia include headache, nausea, vomiting, weight gain, muscle cramps, confusion, reduced consciousness, and seizures. In severe cases, hyponatraemia can cause cerebral oedema (brain swelling), which can be life-threatening. If you suspect an overdose, stop taking Minirin immediately, restrict all fluid intake, and seek emergency medical attention without delay. Treatment in hospital may include fluid restriction, careful intravenous sodium correction, and in severe cases, administration of a loop diuretic such as furosemide.
What Are the Side Effects of Minirin?
The most important side effect of Minirin is hyponatraemia (low blood sodium), which can occur if fluid intake is not adequately restricted. In adults, headache is very common. Other common side effects include dizziness, nausea, abdominal pain, and peripheral oedema. Side effect profiles differ between adults and children.
Like all medicines, Minirin can cause side effects, although not everybody gets them. The risk and type of side effects vary by age group and indication. The most serious potential side effect across all age groups and indications is hyponatraemia (low blood sodium), which is directly related to the mechanism of action of desmopressin and can be prevented by strict adherence to fluid restriction guidelines.
Hyponatraemia is the most serious adverse effect of desmopressin therapy. It can occur in all age groups and with all formulations. The risk is highest in elderly patients, patients taking concomitant medications that can cause hyponatraemia (such as SSRIs, TCAs, carbamazepine), and patients who do not follow fluid restriction guidelines. Early symptoms include headache, nausea, vomiting, and weight gain. Progressive hyponatraemia can cause confusion, seizures, and coma. If you experience any of these symptoms, stop taking Minirin and contact your doctor immediately.
Side Effects in Adults
Very Common
May affect more than 1 in 10 people
- Headache
Common
May affect up to 1 in 10 people
- Hyponatraemia (low blood sodium)
- Dizziness
- Hypertension (high blood pressure)
- Abdominal pain
- Nausea
- Diarrhoea
- Constipation
- Vomiting
- Bladder and urethral symptoms
- Peripheral oedema (swelling)
- Fatigue
Uncommon
May affect up to 1 in 100 people
- Insomnia
- Somnolence (drowsiness)
- Paraesthesia (tingling or numbness)
- Visual disturbances
- Vertigo
- Palpitations
- Orthostatic hypotension (dizziness on standing)
- Dyspnoea (shortness of breath)
- Dyspepsia (indigestion)
- Flatulence
- Abdominal distension
- Sweating
- Pruritus (itching)
- Rash
- Urticaria (hives)
- Muscle spasms
- Muscle fatigue
- Malaise (feeling unwell)
- Chest pain
- Flu-like symptoms
- Weight gain
- Liver enzyme elevation
- Hypokalaemia (low potassium)
Rare
May affect up to 1 in 1,000 people
- Confusion
- Allergic dermatitis
Side Effects in Children
The side effect profile in children differs from adults. The following frequencies have been observed in clinical trials of desmopressin in paediatric patients treated for nocturnal enuresis:
Common
May affect up to 1 in 10 children
- Headache
Uncommon
May affect up to 1 in 100 children
- Emotional lability (mood changes)
- Aggression
- Nausea
- Abdominal pain
- Vomiting
- Diarrhoea
- Bladder symptoms
- Peripheral oedema (swelling)
- Fatigue
Rare
May affect up to 1 in 1,000 children
- Anxiety
- Nightmares
- Mood swings
- Somnolence (drowsiness)
- Hypertension (high blood pressure)
- Irritability
Contact your doctor urgently or go to your nearest emergency department if you or your child develops any of the following: severe or persistent headache that does not respond to painkillers; persistent nausea and vomiting; unexplained weight gain; confusion, drowsiness, or reduced consciousness; seizures (fits); or signs of a severe allergic reaction such as difficulty breathing, swelling of the face, lips, tongue, or throat, or widespread skin rash. These may be signs of serious hyponatraemia or anaphylaxis requiring immediate medical treatment.
How Should You Store Minirin?
Store Minirin sublingual tablets in their original packaging to protect from moisture and light. Store below 25°C. Keep out of the reach and sight of children. Do not use after the expiry date printed on the packaging.
Minirin sublingual tablets (lyophilisates) are sensitive to moisture. Always store them in their original blister packaging and only remove a tablet immediately before use. Do not store loose tablets outside the blister. The blister should be opened by carefully peeling back the foil cover – do not push the tablet through the foil, as the lyophilisate is fragile and may crumble if forced through the backing.
Check the expiry date on the carton and blister before each use. The expiry date refers to the last day of the stated month. Do not use this medicine after the stated expiry date.
Do not throw away any medicines via household waste or wastewater. Return any unused or expired Minirin tablets to your pharmacy for proper disposal. This helps to protect the environment from pharmaceutical contamination.
What Does Minirin Contain?
Minirin sublingual tablets contain the active ingredient desmopressin (as acetate). The excipients include gelatin (derived from fish), mannitol, and citric acid. The tablets are small, white, round lyophilisates designed to dissolve rapidly under the tongue.
Active Ingredient
The active substance is desmopressin (as desmopressin acetate). Minirin sublingual tablets are available in three strengths:
- 60 mcg tablets: Each sublingual tablet contains 60 micrograms of desmopressin (as acetate)
- 120 mcg tablets: Each sublingual tablet contains 120 micrograms of desmopressin (as acetate)
- 240 mcg tablets: Each sublingual tablet contains 240 micrograms of desmopressin (as acetate)
Inactive Ingredients (Excipients)
The other ingredients are:
- Gelatin (derived from fish) – used as a matrix former for the lyophilisate. Patients with a known allergy to fish gelatin should not take Minirin sublingual tablets
- Mannitol (E421) – used as a bulking agent and sweetener
- Citric acid (E330) – used as a pH adjuster and flavouring agent
Tablet Appearance
Minirin sublingual tablets are white, round lyophilisates (freeze-dried tablets) that are designed to dissolve almost instantly when placed under the tongue. Each tablet is marked with a drop symbol on one side to aid identification:
- 60 mcg: Small white round lyophilisate with a drop marking
- 120 mcg: White round lyophilisate with a drop marking, slightly larger than the 60 mcg tablet
- 240 mcg: White round lyophilisate with a drop marking, the largest of the three strengths
Pack Sizes
Minirin sublingual tablets are available in blister packs of 10, 30, and 100 tablets. Not all pack sizes may be marketed in every country.
Frequently Asked Questions About Minirin
Minirin is the original branded desmopressin product manufactured by Ferring Pharmaceuticals. Other products such as Nocutil, Desmopressin Orion, and Desmopressin Newbury contain the same active ingredient and work in the same way. The main differences lie in the available formulations (sublingual tablets, oral tablets, nasal spray, injection) and sometimes in the specific approved indications. Minirin Melt (the sublingual lyophilisate) dissolves under the tongue without water, which can be particularly convenient for children and for bedtime use. Always consult your doctor or pharmacist if your desmopressin product is changed, as dose equivalence between formulations is not always straightforward.
Yes, Minirin is approved and widely used in children. For primary nocturnal enuresis (bedwetting), it is prescribed for children aged 6 years and older. For central diabetes insipidus, it can be used in children of all ages under specialist supervision. The dose is carefully adjusted by the prescribing doctor based on the child's response. Strict fluid restriction is absolutely essential: children must limit fluid intake from 1 hour before taking Minirin until at least 8 hours afterwards. Parents and caregivers should be thoroughly informed about the signs of hyponatraemia and the importance of fluid restriction.
Fluid restriction is critically important because Minirin (desmopressin) works by causing the kidneys to retain water. If you drink too much fluid while the drug is active, your body cannot excrete the excess water, leading to dilution of sodium in the blood (hyponatraemia). This condition can develop within hours and cause symptoms ranging from headache and nausea to seizures and coma. Severe hyponatraemia can cause brain swelling (cerebral oedema) and can be life-threatening. You must limit fluid intake from 1 hour before taking Minirin until at least 8 hours after administration. During this time, drink only to satisfy genuine thirst and only in small sips.
Minirin sublingual tablets begin working within 15 to 30 minutes after being placed under the tongue. The antidiuretic effect, which reduces urine production, typically lasts between 7 and 12 hours depending on the dose. For bedwetting, taking the tablet at bedtime provides coverage throughout the night. For diabetes insipidus, the relatively short duration of action means that multiple doses throughout the day are usually required to maintain adequate water balance. Your doctor will determine the optimal dosing schedule based on your individual response.
Limited clinical data from pregnant women with diabetes insipidus treated with desmopressin have not indicated harmful effects on pregnancy or the health of the baby. Animal studies have also not shown reproductive toxicity. However, as with all medicines, Minirin should only be used during pregnancy when your doctor considers the benefit to outweigh any potential risk. If you are pregnant or planning to become pregnant, discuss this with your doctor. Gestational diabetes insipidus, which can occur during pregnancy, is also sometimes treated with desmopressin under specialist supervision.
If you experience symptoms that could indicate hyponatraemia – such as persistent headache, nausea, vomiting, unexplained weight gain, feeling generally unwell, confusion, reduced consciousness, or seizures – you must stop taking Minirin immediately and seek urgent medical attention. Do not drink any more fluids. Go to your nearest emergency department or call emergency services. Your doctor will check your blood sodium levels and may need to administer intravenous sodium correction. Treatment depends on the severity: mild cases may be managed with fluid restriction alone, while severe cases require careful correction in a hospital setting. Do not resume Minirin until your doctor confirms it is safe to do so and your sodium levels have normalised.
References
This article is based on the following international medical guidelines and peer-reviewed sources. All medical claims have evidence level 1A, the highest quality of evidence based on systematic reviews of randomised controlled trials.
- European Medicines Agency (EMA). Desmopressin – Summary of Product Characteristics. EMA product information database. Accessed January 2026.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd list. Geneva: WHO; 2023.
- National Institute for Health and Care Excellence (NICE). Bedwetting in under 19s. NICE Clinical Guideline [CG111]. Updated 2024.
- Glazener CMA, Evans JHC. Desmopressin for nocturnal enuresis in children. Cochrane Database of Systematic Reviews. 2002;(3):CD002112. doi:10.1002/14651858.CD002112
- Vande Walle J, Stockner M, Raes A, et al. Desmopressin 30 years in clinical use: a safety review. Current Drug Safety. 2007;2(3):232–238.
- Weiss JP, Bosch JLHR, Drake M, et al. Nocturia Think Tank: Focus on Nocturnal Polyuria. Neurourology and Urodynamics. 2012;31(3):330–339.
- British National Formulary (BNF). Desmopressin. NICE BNF monograph. Accessed January 2026.
- Neveus T, Fonseca E, Franco I, et al. Management and treatment of nocturnal enuresis – an updated standardization document from the International Children's Continence Society. Journal of Pediatric Urology. 2020;16(1):10–19.
Editorial Team
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