- Drugs List
- Therapeutic Indications
- Precautions and Warnings
- Pregnancy and Lactation
- Side Effects
Oral formulations of melatonin.
Insomnia in children with ADHD aged 6 years and above
Insomnia with autism or Smith-Magenis Syndrome in children
Jet-lag in adults: short term treatment
Short term treatment of primary insomnia in patients 55 years or over
Short term monotherapy for primary insomnia characterised by poor quality of sleep in adults aged 55 years and above.
Insomnia with Autism Spectrum Disorder and/or Smith-Magenis syndrome in children aged 2 to 18 years where sleep hygiene measures have been insufficient.
Insomnia with ADHD in children aged 6 to 18 years where sleep hygiene measures have been insufficient.
Short term treatment of jet lag in adults. The medicinal product is recommended to adult travellers flying across more than 5 time zones, particularly in an easterly direction, and especially if they have experienced jet lag symptoms on previous journeys. Travellers crossing 2 to 4 time zones can also use if need be.
Sleep onset insomnia and delayed sleep phase syndrome in children
Sleep onset insomnia and/or delayed sleep phase syndrome in children.
Primary insomnia in patients aged 55 years and above
2mg once daily, taken 1 to 2 hours before bedtime, after food.
Maximum treatment duration of thirteen weeks.
Short term treatment of jet lag
3mg once daily for a maximum of 4 days. Some manufacturers recommend a starting dose of 2ml (equivalent to 2mg).The maximum treatment period may vary amongst brands.
Some manufacturers indicate that the dose may be increased to 5mg or 6mg once daily for a maximum of 5 days if necessary. A lower dose of 1mg may be sufficient for some individuals.
The first dose should be taken on arrival at destination at the habitual bed time not before 20:00hr or after 04:00hr at destination.
Melatonin may be taken for a maximum of 16 treatment periods per year.
Insomnia with Autism Spectrum Disorder and/or Smith-Magenis syndrome in children aged 2 years to 18 years
2mg once daily, taken 30 minutes to 1 hour before bedtime, with or after food.
The dose may be increased to 5mg once daily if necessary. Maximum dose 10mg daily.
Insomnia with ADHD in children aged 6 years to 18 years
1mg to 2mg daily, taken 30 minutes to 1 hour before bedtime. Some brands recommend an initial dose of 3mg and are suitable only when the lowest effective dose has been established to be 3mg.
The dose may be increased by 1mg every week. Maximum dose 5mg daily.
Review treatment after 3 months and consider discontinuation if no response is seen. Review ongoing treatment at least every 6 months. Data is available for up to three years of treatment. During ongoing treatment, especially if the treatment effect is uncertain, discontinuation attempts should be done regularly. e.g once per year. If the sleep disorder has started during treatment with medicinal products for ADHD, dose adjustment or switching to another product should be considered.
The following alternative unlicensed dosing schedule may be suitable:
Sleep onset insomnia and/or delayed sleep phase syndrome (unlicensed)
2mg to 3mg daily, before bedtime, for one to two weeks.
The dose may be increased to 4mg to 6mg daily if necessary. Maximum dose 10mg daily.
Additional Dosage Information
Caution is advised when switching between immediate release formulations as the peak plasma-melatonin concentration may be higher with the oral solution than with the tablets.
Children under 2 years
Precautions and Warnings
Children aged 2 to 18 years
Females of childbearing potential
Impaired glucose tolerance
Patients over 65 years
Predisposition to seizures
Glucose-galactose malabsorption syndrome
Hereditary fructose intolerance
ADHD: Treatment to be initiated by a specialist
Advise patient drowsiness may affect ability to drive or operate machinery
Not all available brands are licensed for all age groups
Not all available brands are licensed for all indications
Not all available strengths are licensed for all indications
Presentations with sorbitol unsuitable in hereditary fructose intolerance
Some formulations contain hydroxybenzoate
Some formulations contain lactose
Take at the same time in respect to food as absorption may be affected
Evaluate treatment efficacy regularly
May increase seizure frequency
Dose adjustment required if patient starts/stops smoking during therapy
Maintain treatment for the shortest possible duration
Advise patient to avoid alcohol during treatment
Male & female: May cause infertility
Female: Ensure adequate contraception during treatment
Advise patient to seek medical advice if taking NSAIDs
The effect of renal impairment in melatonin treatment has not been studied. Immediate release formulations are not recommended for patients with severe renal impairment.
Due to the effects of carbohydrate-rich meals on blood glucose, it is advised to take melatonin at least 2 hours before or at least 2 hours after a meal. If the patient has significantly impaired glucose tolerance or diabetes, it is advised to take melatonin at least 3 hours after a meal.
Melatonin treatment may increase the incidence of seizures in children and adolescents with multiple neurological defects.
High doses and long term use may affect fertility, animal studies are insufficient with respect to effects on fertility. Some manufacturers do not recommend melatonin treatment when planning a pregnancy.
Possible long term effects of melatonin have been inadequately studied. There are theoretical risks based on biological effects of melatonin e.g immunological regulation, effects on threshold for seizures and endocrinological effects, which could affect puberty development and fertility, respectively.
Pregnancy and Lactation
Melatonin is contraindicated during pregnancy.
Manufacturers do not recommend using melatonin during pregnancy or in women of childbearing potential not using contraception.
Animal studies do not indicate reproductive toxicity. Human data is limited but melatonin is known to cross the placenta, and as such a potential risk cannot be ruled out.
Melatonin is contraindicated during breastfeeding.
Manufacturers do not recommend breastfeeding whilst taking melatonin.
Animal studies indicate melatonin is transferred into breast milk. The potential risk to exposed infants is unknown however it should be born in mind that endogenous melatonin is a normal component of breast milk. Furthermore, doses higher than those expected in breast milk from maternal supplementation have been used safely in infants. As such, LactMed (2022) indicates short term use is unlikely to have adverse effects in exposed infants.
Some products may be put into food such as yoghurt, orange juice or ice-cream to facilitate swallowing. Some tablets can be crushed and mixed with water directly before administration. Consult product literature for further details. Advise patient to seek medical advice if taking NSAIDs. If possible, administration of NSAIDs should be avoided in the evening. Advise patients that starting or stopping smoking may affect the efficacy of melatonin by changing plasma levels. Advise patients to avoid alcohol during treatment. Alcohol will reduce the effectiveness of melatonin on sleep. Advise patients that melatonin may cause drowsiness. Caution is advised if drowsiness is likely to be associated with a risk to safety. Advise patient to seek advice at first indications of pregnancy. Advise patients their ability to drive or operate machinery may be affected by side effects.
Abnormal liver function tests
Early morning awakening
Gastroesophageal reflux disease
Increases in hepatic enzymes
Oral mucosal blistering
Possible alteration of laboratory tests
Sudden sleep onset episodes
It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.
The following number will direct the caller to the relevant local centre (0844) 892 0111
Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).
Last Full Review Date: November 2020
Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.
Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.
Summary of Product Characteristics: Adaflex 1mg, 2mg, 3mg, 4mg, 5mg tablets. AGB-Pharma AB. Revised November 2021.
Summary of Product Characteristics: Ceyesto 3mg tablets. Alturix Ltd. Revised November 2022.
Summary of Product Characteristics: Circadin 2mg prolonged-release tablets. Flynn Pharma Ltd. Revised August 2019.
Summary of Product Characteristics: Melatonin 1mg/ml oral solution. Colonis Pharma Ltd. Revised January 2020.
Summary of Product Characteristics: Melatonin 1mg/ml oral solution. Consilient Health Ltd. Revised March 2022.
Summary of Product Characteristics: Melatonin 2mg hard capsules. Colonis Pharma Ltd. Revised July 2020.
Summary of Product Characteristics: Melatonin 3mg film coated tablets. Colonis Pharma Ltd. Revised April 2019.
Summary of Product Characteristics: Melatonin 3mg film coated tablets. Pharma Nord Ltd. Revised September 2019.
Summary of Product Characteristics: Slenyto 1mg prolonged-release tablets and 5mg prolonged-release tablets. Flynn Pharma Ltd. Revised May 2020.
Summary of Product Characteristics: Syncrodin 3mg film coated tablets. Pharma Nord Ltd. Revised June 2020.
NICE Evidence Services Available at: www.nice.org.uk Last accessed: 09 December 2022
US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
Available at: https://www.ncbi.nlm.nih.gov/books/NBK501922/
Melatonin. Last revised: 30 November 2022
Last accessed: 09 December 2022
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Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content
FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.