Review Drug

Melatonin

Brand names None (not commercially available in the United Kingdom)
Used in the following combined preparations None

General Information

Melatonin is a natural hormone that is secreted during the hours of darkness by the pineal gland in the brain. It is involved in the control of the body’s circadian (day-night) rhythm, the ability to sleep during the hours of darkness and stay awake during daylight hours. It may also be involved in the organization of seasonal rhythms and the timing of pubertal development.

When given as a drug, melatonin induces sleep and decreases alertness, body temperature, and performance. It is sometimes given to blind people, to regulate a disturbed circadian rhythm, and to shift-workers to alter the internal body clock. It has also been used to reduce the effects of jet lag by resetting the internal body clock.

Other conditions for which melatonin therapy has been proposed include the prevention of coronary heart disease, because of the drug’s antioxidant effect, as well as the treatment of epilepsy and sarcoidosis. The drug may also have a role in cancer treatment. However, there is as yet no scientific evidence that it is of benefit for these conditions.

QUICK REFERENCE

Drug group Hormone
Overdose danger rating Low
Dependence rating Not known – awaiting results of controlled clinical trials

Prescription needed Yes Available as generic No

Information for Users
Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken

Various oral formulations are under investigation.

Frequency and timing of doses

Dependent on formulation and indication.

Adult dosage range

Dependent upon condition being treated.

Onset of effect

Sleep may be induced within 30 minutes.
Duration of action

3-4 hours.

Diet advice

None.

Storage

Keep in a closed container in a cool, dry place out of the reach of children.

Missed dose

Take as soon as you remember. Stopping the drug

Can be safely stopped as soon as you no longer need it.

Exceeding the dose

Not known.

Possible Adverse Effects

Melatonin has been used in only a small number of people and there are few published reports. Thus the adverse effects (both short-and long-term) of its use are not yet known.
Drowsiness and impaired alertness have been noticed after taking melatonin, not because the drug acts like other sedative drugs, but because it induces sleep naturally.
 

Interactions

No information available.

Special Precautions

Be sure to tell your doctor if:

You are taking other medications.

Pregnancy

Not usually prescribed. Safety in pregnancy not established. Discuss with your doctor.

Breast-feeding

Not usually prescribed. Safety in breast-feeding not established. Discuss with your doctor.

Infants and children

Not recommended.
 
Over 60

No data available.
 
Driving and hazardous work

  Avoid such activities until you have learned how melatonin affects you because the drug causes sedation and impaired alertness.

Alcohol

Avoid. Alcohol may increase the sedative effects of this drug.
 

Prolonged Use

No information available on the long-term use of melatonin.