Microlut (Levonorgestrel)

• Microlut (levonorgestrel) is a progestogen‑only hormonal contraceptive acting within the reproductive health pathway.
• Contraception (prevention of pregnancy): provides reliable daily birth control for women of reproductive age.
• Emergency contraception (post‑coital use of levonorgestrel): a single high‑dose regimen can prevent pregnancy after unprotected intercourse, though this is a different dosage form than the daily tablet.
• Menstrual cycle regulation (reduction of irregular bleeding): helps stabilize the endometrial lining and may lessen breakthrough bleeding.

• Levonorgestrel binds to progesterone receptors in the hypothalamus and pituitary, suppressing the luteinizing hormone surge that triggers ovulation. It also induces changes in the cervical mucus, making it thicker and less permeable to sperm, and alters the endometrial lining to reduce the likelihood of implantation. These combined actions prevent fertilization and pregnancy. The progestogenic effect also provides a stable hormonal environment that supports the contraceptive efficacy throughout the menstrual cycle.

Levonorgestrel may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Headache: mild to moderate headache may occur.
• Nausea: occasional nausea or stomach upset.
• Breast tenderness: mild breast discomfort.
• Irregular bleeding: spotting or changes in menstrual flow.

Serious or Rare Side Effects

• Deep vein thrombosis: rare clot formation in veins.
• Severe allergic reaction: rash, swelling, or anaphylaxis.
• Hepatic dysfunction: signs of liver injury such as jaundice.

Before prescribing Microlut, clinicians should evaluate several safety considerations.

• Assess cardiovascular risk: review history of thromboembolic disorders or smoking in women over 35.
• Screen for liver disease: avoid use in active hepatic impairment.
• Evaluate breast health: contraindicated in known or suspected breast cancer.
• Review medication adherence: daily intake at the same time is essential for effectiveness.
• Consider interactions with enzyme‑inducing drugs: may reduce contraceptive efficacy.
• Store at ambient temperature: keep tablets below 25 °C in the original packaging, protected from moisture.

Levonorgestrel’s effectiveness can be altered by other medicines.

Major Interactions (Avoid)

• Enzyme‑inducing antiepileptics (e.g., carbamazepine, phenytoin): significantly lower plasma levonorgestrel levels.
• Rifampin or rifabutin: reduce contraceptive efficacy and increase risk of unintended pregnancy.
• St. John’s Wort: herbal inducer that may diminish hormonal protection.

Moderate Interactions (Monitor Closely)

• Antifungal agents (e.g., ketoconazole, itraconazole): may increase levonorgestrel concentrations.
• Certain antibiotics (e.g., tetracycline, metronidazole): can slightly decrease effectiveness.
• Protease inhibitors (e.g., ritonavir): may affect metabolism and require monitoring.