Levonorgestrel Abece (Levonorgestrel)

Levonorgestrel acts on the hormonal pathways that regulate ovulation and endometrial development.

• Emergency contraception: prevents pregnancy after unprotected intercourse when taken within the recommended time window.
• Birth control (progestin‑only pill): provides daily hormonal contraception for women seeking a non‑estrogen regimen.
• Menstrual cycle regulation: can be used to adjust timing of the menstrual period in certain clinical protocols.

• Levonorgestrel binds with high affinity to progesterone receptors in the hypothalamus and pituitary, suppressing the luteinizing hormone surge and thereby inhibiting ovulation. It also induces changes in the cervical mucus and endometrial lining, reducing sperm penetration and making the uterine environment unsuitable for implantation.

Levonorgestrel is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Headache: transient tension‑type headache.
• Breast tenderness: mild discomfort in the breast tissue.
• Irregular bleeding: spotting or changes in menstrual flow.
• Fatigue: temporary feeling of tiredness.

Serious or Rare Side Effects

• Allergic reaction: rash, itching, swelling, or difficulty breathing.
• Severe abdominal pain: may indicate ectopic pregnancy.
• Thromboembolic events: rare clot formation, especially in high‑risk individuals.
• Chest pain or shortness of breath: possible cardiovascular involvement.
• Liver dysfunction: jaundice or abnormal liver tests.

Levonorgestrel should be used with awareness of specific safety considerations.

• Contraindications: known hypersensitivity to levonorgestrel or any tablet excipients.
• Liver disease: avoid in active severe hepatic impairment.
• Timing: must be taken as soon as possible after unprotected intercourse for maximum efficacy.
• Pregnancy status: ensure the patient is not already pregnant before administration.
• Drug interactions: review concomitant medications that may reduce effectiveness.
• Store at ambient temperature: keep in the original packaging, protect from moisture and direct sunlight.

Levonorgestrel may have clinically relevant interactions with several drug classes.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine, phenytoin): may markedly reduce contraceptive efficacy.
• Enzyme‑inducing anticonvulsants: can lower plasma levels of levonorgestrel.

Moderate Interactions (Monitor Closely)

• Antifungal agents (e.g., ketoconazole): may modestly decrease effectiveness.
• Certain antibiotics (e.g., ampicillin): occasional reports of reduced contraceptive reliability.
• St. John’s wort: herbal inducer that could lower hormone levels.
• Antiretroviral drugs (e.g., efavirenz): may require additional contraceptive measures.