Formulary
Melatonin: Indications, Dosing, Side Effects and Interactions
Melatonin clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 4 min read
Melatonin: Indications, Dosing, Side Effects and Interactions
Melatonin clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Insomnia [short-term use]**
- **Adult** (By Mouth Using Modified-Release Tablets): 55 years and over 2 mg once daily for up to 13 weeks, dose to be taken 1-2 hours before bedtime.
**Jet lag [short-term use]**
- **Adult** (By Mouth Using Immediate-Release Medicines): 3 mg once daily for up to 5 days, the first dose should be taken at the habitual bedtime after arrival at destination. Doses should not be taken before 8 p.m. or after 4 a.m, dose may be increased to 5 or 6 mg once daily if necessary, or reduced to 1 or 2 mg once daily if sufficient. Maximum of 16 treatment courses per year.
**Insomnia in patients with learning disabilities and behaviour that challenges [where sleep hygiene measures have been insufficient] (initiated under specialist supervision)**
- **Adult** (By Mouth Using Modified-Release Tablets): Initially 2 mg once daily, dose to be taken 30-60 minutes before bedtime, increased if necessary to 4-6 mg once daily, dose to be taken 30-60 minutes before bedtime, dose can be increased if necessary up to maximum 10 mg per day.
**Sleep onset insomnia (initiated under specialist supervision), Delayed sleep phase syndrome (initiated under specialist supervision) for melatonin**
- **Child** (By mouth using modified-release tablets): Initially 2-3 mg once daily for 1-2 weeks, dose to be taken before bedtime, then increased if necessary to 4-6 mg once daily, dose to be taken before bedtime, dose can be increased if necessary up to maximum 10 mg per day.
**Insomnia in patients with learning disabilities and behaviour that challenges [where sleep hygiene measures have been insufficient] (initiated under specialist supervision) for melatonin**
- **Child** (By mouth using modified-release tablets): Initially 2 mg once daily, dose to be taken 30-60 minutes before bedtime, increased if necessary to 4-6 mg once daily, dose to be taken 30-60 minutes before bedtime, dose can be increased if necessary up to maximum 10 mg per day.
**Insomnia in patients with ADHD [where sleep hygiene measures have been insufficient] (initiated under specialist supervision) for melatonin**
- **Child 6-17 years** (By mouth using immediate-release medicines): Initially 1-2 mg once daily, dose to be taken 30-60 minutes before bedtime, increased if necessary up to 5 mg once daily, dose to be taken 30-60 minutes before bedtime, dose to be increased in steps of 1 mg at weekly intervals.
**Insomnia with autism spectrum disorder [where sleep hygiene measures have been insufficient], Insomnia with Smith-Magenis syndrome [where sleep hygiene measures have been insufficient] for Slenyto**
- **Child 2-17 years** (By mouth using modified-release tablets): Initially 2 mg once daily, dose to be taken 30-60 minutes before bedtime, increased if necessary to 5 mg once daily, dose to be taken 30-60 minutes before bedtime, dose can be increased if necessary up to maximum 10 mg per day.
Cautions
Autoimmune disease; susceptibility to seizures (risk of increased seizure frequency) Cautions, further information Autoimmune disease Avoid-limited information available in patients with autoimmune disease; exacerbation reported occasionally. M
Side effects
Common or very common Arthralgia; increased risk of infection; pain Uncommon Anxiety; asthenia; chest pain; dizziness; drowsiness; dry mouth; gastrointestinal discomfort; headaches; hyperbilirubinaemia; hypertension; menopausal symptoms; mood altered; movement disorders; nausea; night sweats; oral disorders; skin reactions; sleep disorders; urine abnormalities; weight increased Rare or very rare Aggression; angina pectoris; arthritis; concentration impaired; crying; depression; disorientation; electrolyte imbalance; excessive tearing; gastrointestinal disorders; haematuria; hot flush; hypertriglyceridaemia; leucopenia; memory loss; muscle complaints; nail disorder; palpitations; paraesthesia; partial complex seizure; prostatitis; sexual dysfunction; syncope; thirst; thrombocytopenia; urinary disorders; vertigo; vision disorders; vomiting Frequency not known Angioedema; galactorrhoea; hyperglycaemia
Interactions
**Other interactions (5):**
- Pharmacokinetic interactions Melatonin is metabolised mainly by the hepatic cytochrome P450 CYP1A enzymes, primarily CYP1A2.
- Therefore, interactions between melatonin and other active substances as a consequence of their effect on CYP1A enzymes are possible.
- This combination should be avoided.
- Pharmacodynamic interactions Melatonin may enhance the sedative effect of benzodiazepines (e.g.
- In a study of jet-lag therapy the combination of melatonin and zolpidem resulted in a higher incidence of morning sleepiness, nausea, and confusion, and reduced activity during the first hour after...
Pregnancy
No information available-avoid.
Breast feeding
Present in milk-avoid.
Hepatic impairment
For modified-release tablets , avoid (risk of decreased clearance; limited information available). M For immediate-release formulations , avoid in moderate or severe impairment (risk of decreased clearance; limited information available). M
Renal impairment
For modified-release tablets , caution (no information available). M For immediate-release formulations , caution (increased risk of exposure; limited information available); avoid in severe impairment. M
Medicinal forms
Tablet,Tablet,Tablet,Capsule,Solution
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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