Levonorgestrel Teva (Levonorgestrel)

Levonorgestrel works on the hormonal regulation of the menstrual cycle to prevent pregnancy.

• Emergency contraception: prevents pregnancy after unprotected intercourse when taken within the recommended time frame.
• Regular contraception: provides ongoing prevention of ovulation when used as directed in a daily regimen.
• Hormonal regulation: alters the endometrium to reduce the likelihood of implantation.

• Levonorgestrel binds to progesterone receptors in the hypothalamus and pituitary, suppressing the luteinizing hormone surge that triggers ovulation. By maintaining elevated progestogenic activity, it inhibits follicular rupture and modifies the endometrial lining, making it less receptive to a fertilized egg. The combined effect prevents both ovulation and implantation, providing contraceptive efficacy.

Levonorgestrel may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Headache: transient tension‑type headaches.
• Abdominal pain: cramping or discomfort in the lower abdomen.
• Fatigue: feeling unusually tired.
• Breast tenderness: mild soreness of the breasts.
• Menstrual changes: spotting or altered flow.

Serious or Rare Side Effects

• Thromboembolic events: deep vein thrombosis or pulmonary embolism.
• Severe allergic reaction: rash, swelling, or difficulty breathing.
• Liver dysfunction: jaundice or abnormal liver enzymes.
• Ectopic pregnancy: implantation outside the uterus.
• Persistent abdominal pain: may indicate serious complications.

When prescribing Levonorgestrel, clinicians should consider several precautionary measures to ensure safe use.

• Contraindications: verify no history of thromboembolic disorders, severe liver disease, or known hypersensitivity.
• Medical history: assess for hormonal disorders, pregnancy, or breastfeeding status.
• Drug interactions: review concomitant medications that may reduce efficacy.
• Monitoring: observe for signs of abnormal bleeding or severe abdominal pain.
• Storage: Store at ambient temperature below 25°C: keep in the original packaging, protect from moisture and light.

Levonorgestrel can interact with other medicines, affecting its contraceptive effectiveness.

Major Interactions (Avoid)

• Rifampin and other enzyme inducers: may markedly reduce contraceptive efficacy.
• St. John’s wort: herbal inducer that can lower drug levels.
• Certain hormonal therapies: may interfere with progestogenic activity.

Moderate Interactions (Monitor Closely)

• Antifungal agents such as ketoconazole: may increase plasma concentrations.
• Antiretroviral drugs (e.g., efavirenz): may modestly reduce effectiveness.
• Some antibiotics (e.g., griseofulvin): may slightly diminish contraceptive reliability.