Norlevo (Levonorgestrel)

Levonorgestrel is used in the emergency contraception pathway to prevent unintended pregnancy after a single episode of unprotected intercourse.

• Unprotected sexual intercourse: provides emergency contraception to lower the chance of pregnancy.
• Contraceptive failure: serves as a backup method when a regular method fails.
• Delayed ovulation: postpones ovulation to prevent fertilisation.

• Levonorgestrel binds to progesterone receptors in the hypothalamic‑pituitary‑ovarian axis, inhibiting the luteinising hormone surge that triggers ovulation. By preventing or delaying the release of an oocyte, it reduces the likelihood of fertilisation. If ovulation has already occurred, levonorgestrel may also impair sperm transport or fertilisation and may alter endometrial receptivity, thereby decreasing the chance of implantation.

Levonorgestrel is generally well tolerated, but some users experience adverse reactions.

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Headache: transient cranial discomfort.
• Abdominal pain or cramps: intermittent lower‑abdominal discomfort.
• Fatigue: temporary feeling of tiredness.
• Menstrual changes: spotting or altered timing of the next period.
• Dizziness: brief episodes of light‑headedness.

Serious or Rare Side Effects

• Allergic reaction: rash, itching, swelling, or difficulty breathing.
• Severe abdominal pain: persistent or worsening pain.
• Chest pain or palpitations: unusual cardiac sensations.
• Persistent vomiting: inability to retain fluids.
• Signs of ectopic pregnancy: sharp pelvic pain with vaginal bleeding.
• Unusual bleeding: heavy or prolonged vaginal bleeding.

Levonorgestrel should be used according to professional guidance and with awareness of specific safety considerations.

• Timing of use: take as soon as possible after the event, ideally within 72 hours.
• Pregnancy status: do not use if a confirmed pregnancy exists.
• Liver disease: avoid in severe hepatic impairment.
• Repeated use: limit frequent use; consider regular contraception for ongoing protection.
• Drug interactions: review concomitant medications that may reduce efficacy.
• Store at ambient temperature below 25°C: keep in the original pack, protect from moisture.

Levonorgestrel may have its effectiveness altered by other medicines.

Major Interactions (Avoid)

• Rifampicin or other strong enzyme inducers: may markedly reduce levonorgestrel levels.
• St John’s wort: can decrease hormonal efficacy.
• Anticonvulsants (e.g., carbamazepine, phenytoin): may lower contraceptive effect.

Moderate Interactions (Monitor Closely)

• Antacids or iron supplements: may slightly affect absorption if taken simultaneously.
• Hormonal therapies (e.g., combined oral contraceptives): monitor for reduced overall contraceptive protection.
• Certain antibiotics (e.g., griseofulvin): may modestly diminish effectiveness.