Melatonine Lp Venipharm (Melatonin)

Melatonin acts on the melatonin receptor pathway to support normal sleep regulation.

• Insomnia: helps reduce sleep onset latency and improve sleep continuity.
• Jet lag: assists in adjusting the internal clock after rapid time‑zone travel.
• Circadian rhythm sleep disorders: supports synchronization of disrupted sleep‑wake cycles.

• Melatonin binds to MT1 and MT2 receptors in the suprachiasmatic nucleus, mimicking endogenous melatonin. Activation of these G‑protein‑coupled receptors reduces neuronal firing during the night, signaling darkness and promoting the initiation of sleep. By modulating the circadian clock, the drug helps align the body’s internal rhythm with the external light‑dark cycle, facilitating sleep onset. The effect is dose‑dependent and typically peaks within an hour after oral administration.

Melatonin is generally well tolerated, but some users may experience adverse reactions. While most side effects are mild and transient, patients should be aware of the range of possible reactions.

Common Side Effects

• Drowsiness: feeling of sleepiness during the day.
• Headache: mild to moderate head pain.
• Dizziness: sensation of light‑headedness.
• Gastrointestinal discomfort: nausea or stomach upset.
• Vivid dreams: unusually intense or memorable dreams.
• Mood swings: mild irritability or emotional fluctuations.

Serious or Rare Side Effects

• Allergic reaction: rash, itching, swelling, or difficulty breathing.
• Mood changes: depression or increased anxiety in susceptible individuals.
• Hormonal effects: alterations in menstrual cycle or reduced fertility with prolonged high‑dose use.

When using Melatonin, certain precautions should be observed to ensure safe and effective use.

• Assess suitability: evaluate underlying sleep disorder and medical history before starting.
• Avoid driving: do not operate machinery or drive if drowsiness occurs.
• Drug interactions: review concomitant medications for potential interactions.
• Pregnancy and lactation: consult a healthcare professional before use during pregnancy or breastfeeding.
• Age considerations: use lower doses in elderly patients due to increased sensitivity.
• Store at ambient temperature: keep below 25 °C in the original container, protect from moisture and light.

Melatonin may interact with several medicines, altering its effectiveness or increasing adverse effects. Patients should discuss all current medications with their prescriber.

Major Interactions (Avoid)

• Anticoagulants: may increase bleeding risk when combined with warfarin or similar agents.
• Immunosuppressants: can reduce efficacy of drugs such as cyclosporine.

Moderate Interactions (Monitor Closely)

• Sedatives: additive drowsiness when taken with benzodiazepines or antihistamines.
• Antidepressants: possible serotonin syndrome risk with SSRIs or MAO inhibitors.
• Oral contraceptives: melatonin may affect hormone levels, requiring monitoring.
• Antidiabetic drugs: may influence blood glucose control, requiring dose adjustment.