Nacrez (Desogestrel)

Desogestrel, a third‑generation progestin, is used within the hormonal contraceptive pathway to prevent pregnancy.

• Prevention of pregnancy: provides reliable contraceptive protection when taken as directed.

• Desogestrel binds to progesterone receptors in the hypothalamus and pituitary, suppressing the luteinizing hormone (LH) surge and thereby inhibiting ovulation. It also induces changes in cervical mucus, making it thicker and less permeable to sperm, and alters endometrial development to reduce implantation potential.

Desogestrel may cause a range of adverse reactions, from mild to serious.

Common Side Effects

• Nausea: mild stomach upset that often resolves with continued use.
• Headache: transient tension‑type headaches.
• Breast tenderness: mild discomfort or swelling of the breasts.
• Irregular bleeding: spotting or changes in menstrual flow.
• Weight gain: modest increase in body weight.
• Mood changes: occasional irritability or mood swings.

Serious or Rare Side Effects

• Deep vein thrombosis: blood clot formation in deep veins.
• Pulmonary embolism: clot migration to the lungs, a medical emergency.
• Severe allergic reaction (anaphylaxis): rash, swelling, difficulty breathing.
• Hepatic dysfunction: abnormal liver enzyme elevations.
• Vision disturbances: rare cases of visual impairment.
• Severe hypertension: sudden increase in blood pressure.

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

• Pregnancy: not indicated for use during pregnancy; discontinue if pregnancy occurs.
• Breastfeeding: assess risk versus benefit, as drug may pass into milk.
• Smoking: avoid in women over 35 who smoke due to increased thrombotic risk.
• History of thromboembolic disorders: contraindicated in patients with prior clotting events.
• Drug interactions: review concomitant medications that may affect efficacy.
• Store at ambient temperature: keep below 25°C, retain in original packaging, protect from moisture.

Desogestrel can interact with several drug classes, requiring careful management.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampicin, carbamazepine, phenytoin): may markedly reduce contraceptive effectiveness.
• Antifungal azoles (e.g., ketoconazole, itraconazole): can increase plasma concentrations, raising risk of side effects.
• Protease inhibitors (e.g., ritonavir): may alter hormone levels and affect efficacy.

Moderate Interactions (Monitor Closely)

• Certain antibiotics (e.g., tetracycline, metronidazole): may slightly diminish contraceptive reliability.
• St. John’s wort (hypericum perforatum): herbal inducer that can lower hormone levels.
• Anticonvulsants with moderate enzyme induction (e.g., valproic acid): require monitoring of contraceptive effect.