Lencya (Ulipristal Acetate)

Lencya (ulipristal acetate) is employed in reproductive health and gynecologic conditions where modulation of progesterone receptors is required.

• Emergency contraception: prevents pregnancy when taken up to five days after unprotected intercourse.
• Uterine fibroids: may reduce fibroid size and control associated bleeding in women for whom surgery is not indicated.
• Ovulation delay: postpones follicular rupture to avoid fertilization in the menstrual cycle.

• Ulipristal acetate acts as a selective progesterone receptor modulator, binding to progesterone receptors in the hypothalamus, pituitary, and ovary. This binding alters receptor conformation, inhibiting the luteinizing hormone surge required for ovulation and thereby preventing fertilization. In uterine tissue, the modulation can lead to reduced proliferation of fibroid cells, contributing to size reduction and symptom control.

Ulipristal acetate can cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Headache: transient cranial discomfort.
• Abdominal pain: cramping or lower‑abdomen discomfort.
• Fatigue: feeling unusually tired.
• Menstrual changes: spotting or altered cycle timing.

Serious or Rare Side Effects

• Severe allergic reaction: rash, swelling, or difficulty breathing.
• Liver injury: elevated liver enzymes or jaundice.
• Ectopic pregnancy: implantation outside the uterus if fertilization occurs.
• Thromboembolic events: rare clot formation.
• Uterine rupture: extremely rare in women with fibroids undergoing surgery.

Before prescribing Lencya, clinicians should evaluate patient history and potential risk factors.

• Timing of intercourse: confirm that unprotected sex occurred within five days.
• Pregnancy status: avoid use if pregnancy is already established.
• Hepatic function: assess liver health, especially in patients with known disease.
• Concomitant CYP3A4 inducers: review medications that may reduce efficacy.
• Store at ambient temperature: keep in the original packaging, protect from moisture and direct sunlight.

Ulipristal acetate may interact with other medicines that affect its metabolism or hormonal activity.

Major Interactions (Avoid)

• Rifampicin: strong CYP3A4 inducer that markedly reduces exposure.
• Carbamazepine: enzyme inducer that can lower effectiveness.
• St. John’s wort: herbal CYP3A4 inducer that may compromise efficacy.

Moderate Interactions (Monitor Closely)

• Combined oral contraceptives: may experience reduced contraceptive effect.
• Ketoconazole: potent CYP3A4 inhibitor that could increase drug levels.
• Macrolide antibiotics (e.g., erythromycin): moderate CYP3A4 inhibition requiring monitoring.