Melatonin

Medication Information Leaflet

What is this medication for?

Melatonin is used for short-term treatment of insomnia (difficulty sleeping).
It may also be used for other conditions. Check with your healthcare professional if you are unsure why you are given this medication.

How should I take/use this medication?

  • Follow the instructions on your medication label and take this medication as prescribed by your doctor. 
  • This medication should be taken with or after food.
  • This medication should be taken shortly (1 – 2 hours) before going to bed.
  • The prolonged-release (PR) tablet must be swallowed whole with water or other liquids; do not crush, chew or cut into half.

What should I do if I forget to take/use this medication?

If you are directed by your doctor to take the medication regularly and forget to take a dose, take it as soon as you remember, before going to sleep, or wait until it is time to take your next dose, then go on as before. Do not take two doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if: 
  • You are allergic to this medication or any of the other ingredients of this medication
  • You are pregnant, planning to become pregnant, or breastfeeding. If you are pregnant and/or breastfeeding, your doctor would have discussed the potential benefits and side-effects with you. If you have further questions or concerns, do consult your doctor.
  • You are taking any other medications including over-the-counter medications, supplements, traditional Chinese medicine and herbal remedies. Some of them may affect how this medication works or cause serious drug interactions.
  • You are smoking. Smoking may decrease the amount of Melatonin that stays in your body.
  • You have or have ever had:
    • Other drug allergies or lactose intolerance (congenital galactosaemia, glucose malabsorption syndrome or lactase deficiency)
    • Medical conditions such as:
      • Lung, liver or kidney disease
      • Drug or alcohol abuse
      • Sleep apnea (temporary stopping of breathing during sleep) or 
      • Any autoimmune disease (where the body is ‘attacked’ by its own immune system)

What are some common side-effects of this medication?

The mentioned side effects generally affect up to 10% of patients.
  • Nausea or vomiting
    • Take this medication with or after food
    • Take simple meals and avoid rich or spicy foods
  • Light-headedness (especially during a sudden change in posture)
    • Get up slowly from a sitting or lying down position
  • Feeling tired or drowsy
    • Avoid driving or engaging in activities requiring concentration
  • Feeling clumsy or unsteady 
    • Speak to your doctor if it becomes bothersome
  • Headache
    • Speak to your doctor if it becomes bothersome
Most of the side effects listed here will improve with time. Speak to your doctor if they continue, get worse or are affecting your daily life.

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following: 
  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body
Rarely this medication may cause:
  • Fever
  • Severe chest pain
  • Irregular heartbeat
  • Memory loss (amnesia)
  • Abnormal thinking or changes in behaviour
  • Unusual excitement, nervousness, irritability, or agitation
  • Blurred vision
  • Fainting episodes
  • Seizures (fits)
If you experience any of these side effects, you should stop your medication and inform your healthcare professional immediately.

Please also take note that not all possible side effects are listed above. If you have any concerns about your medication, please consult your doctor or pharmacist.

What food or medication should I avoid when I take this medication?

Avoid drinking alcohol while taking this medication as it can reduce the effect of this medication on sleep.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 

How should I throw away this medication safely?

Pack this medication into a trash bag and seal it tightly before throwing into the rubbish chute or bin.


Disclaimers
If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Oct 2021
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