MELATONIN

brands

Class

• Neuroscience-based Nomenclature: Melatonin Receptor Agonist
• Melatonin (Hormone, Chronobiotic, Sedative-Hypnotic)

MELATONIN commonly prescribed for

(Bold for FDA approved)

How MELATONIN works

• Binds to Melatonin Receptors (MT1 and MT2):

• Synchronizes the sleep-wake cycle by acting on the hypothalamic suprachiasmatic nucleus (SCN), which regulates circadian rhythms.

• MT1 receptor activation: Promotes sleep onset by inhibiting neuronal firing in the SCN.

• MT2 receptor activation: Helps regulate the timing of the circadian clock.

How long until MELATONIN works

• Immediate effects on sleep onset may be noticeable within 30 minutes to 2 hours of taking a dose, depending on the formulation and individual sensitivity.

• Full regulation of the circadian rhythm may take several days to a few weeks of consistent, nightly use.

Notable Side Effects

• Common:

• Sedation, daytime drowsiness, fatigue

• Headache

• Dizziness, lightheadedness

• Nausea

• Vivid dreams or nightmares

• Uncommon/Rare:

• Irritability, nervousness

• Mood changes (e.g., mild depressive symptoms)

• Mild gastrointestinal disturbances (e.g., abdominal cramps)

• Allergic reactions (e.g., rash, itching)

Life Threatening Side Effects

• Extremely rare and generally associated with misuse or interactions:

• Severe drowsiness or lethargy, especially when combined with other CNS depressants.

• Hypersensitivity reactions (e.g., anaphylaxis).

weight gain

unusual

sedation

common

What to do about MELATONIN side effects

• Wait

• Wait

• Wait

• Lower the dose

• Take dose at bedtime to avoid sedative effects during the day

• Switch to another agent

usual dosage range

• Insomnia or Circadian Rhythm Disorders: 1–10 mg/day, typically 30–120 minutes before bedtime.

• Most individuals respond well to doses of 1–5 mg/day.

• Jet Lag: 0.5–5 mg/day for a few days before travel and up to several days after arriving at the destination.

• Sleep Disorders in Children (e.g., neurodevelopmental conditions): Start with 0.5–1 mg/day, titrating up to a maximum of 6–10 mg/day based on response.

Dosage Forms

• Immediate-Release Tablets/Capsules: 1 mg, 3 mg, 5 mg, and 10 mg

• Sublingual Tablets: 0.5 mg to 3 mg

long term use

• Long-term use is generally safe and effective for chronic sleep or circadian rhythm disorders when taken as directed.

• Tolerance to therapeutic effects is rare but may occur with prolonged use.

habit forming

• Not Habit Forming

Renal Impairment

• No Dose Adjustment Typically Required

Hepatic Impairment

• Dose Should Be Reduced

Cardiac Impairment

• Generally Safe for Use: No direct effects on cardiac function

Elderly

• Lower Doses Recommended

Children and Adolescents

• Initial dose: 0.5–1 mg at bedtime, adjusted based on response.

• Maximum dose: 6–10 mg/day

Pregnancy

• Limited data on safety; potential effects on fetal development are unknown.

• If used, restrict to low doses (0.3–1 mg/day) and only in the later stages of pregnancy.

• Discontinue melatonin if unnecessary and taper gradually to avoid circadian disruption.

Breast Feeding

• Small amounts of melatonin may pass into breast milk.

• Effects on the nursing infant are unknown but likely minimal due to the short half-life.

• Consider discontinuing melatonin or monitoring the infant for signs of sedation or feeding issues.