Melatonina Lek-Am (Melatonin)

Melatonin acts on the melatonin receptor pathway to address sleep‑related disorders.

• Insomnia: helps reduce sleep latency and improve total sleep time in individuals with difficulty initiating or maintaining sleep.
• Sleep onset difficulties: facilitates quicker transition to sleep by synchronising circadian rhythms.
• Jet lag: assists in adjusting the internal clock after rapid time‑zone travel, reducing daytime sleepiness and nighttime wakefulness.

• Melatonin binds to MT1 and MT2 receptors in the suprachiasmatic nucleus, mimicking the endogenous hormone released during darkness. This agonist activity modulates the circadian timing system, promoting physiological signalling that signals the body to prepare for sleep. By enhancing receptor activation, it helps reset the internal clock and supports normal sleep‑wake patterns.

Melatonin may be associated with a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Drowsiness: feeling of sleepiness during daytime.
• Headache: mild to moderate head pain.
• Dizziness: sensation of light‑headedness.
• Gastrointestinal discomfort: nausea or abdominal cramps.

Serious or Rare Side Effects

• Allergic reactions: rash, itching, swelling, or anaphylaxis.
• Mood changes: depression, irritability, or vivid dreams.

When considering melatonin therapy, several safety considerations should be observed.

• Pregnancy: safety has not been established; use only if clearly needed.
• Breastfeeding: potential transfer to infant; evaluate risk versus benefit.
• Concomitant CNS depressants: may enhance sedative effects; monitor alertness.
• Underlying medical conditions: assess for depression, epilepsy, or autoimmune disorders before use.
• Age restrictions: not recommended for children without medical supervision.
• Store at ambient temperature: keep below 25 °C in the original container, protect from moisture and light.

Melatonin can interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Anticoagulants: may increase bleeding risk; avoid concurrent use.
• Immunosuppressants: potential reduction in immunosuppressive effect; avoid combination.

Moderate Interactions (Monitor Closely)

• Sedatives or hypnotics: additive sleep‑inducing effect; monitor for excessive drowsiness.
• Oral contraceptives: may reduce melatonin metabolism, increasing levels; observe for heightened effects.
• Antidepressants (SSRIs, MAOIs): possible serotonin syndrome; watch for symptoms.
• Caffeine: may counteract melatonin’s sleep‑promoting action; advise timing adjustments.