Mercilon (Desogestrel, Ethinylestradiol)

• Mercilon, a combined oral contraceptive, is used to prevent pregnancy by modulating the hormonal regulation of the menstrual cycle.
• Contraception: provides reliable prevention of unintended pregnancy when taken as directed.
• Family planning: enables women to plan and space pregnancies for optimal reproductive health.
• Menstrual cycle control: may help achieve more regular menstrual bleeding patterns.

• Desogestrel acts as a progestogenic agent that suppresses the mid‑cycle luteinizing hormone surge, thereby inhibiting ovulation. Ethinylestradiol supplies estrogenic activity that stabilises the endometrial lining and enhances the progestin’s effect on cervical mucus, making it thicker and less permeable to sperm. The combined hormonal action blocks fertilisation and implantation when the tablet is taken daily.

Common Side Effects

• Nausea: mild to moderate stomach upset, especially during the first cycles.
• Breast tenderness: transient swelling or discomfort of the breasts.
• Headache: occasional tension‑type or migraine‑like headaches.
• Irregular bleeding: spotting or breakthrough bleeding between periods.
• Mood changes: mild fluctuations in mood or emotional state.

Serious or Rare Side Effects

• Venous thromboembolism: deep‑vein thrombosis or pulmonary embolism, requiring immediate medical attention.
• Arterial thrombosis: increased risk of stroke or myocardial infarction, particularly in smokers over 35.
• Severe allergic reaction: rash, swelling, or anaphylaxis.
• Liver dysfunction: jaundice or abnormal liver enzyme levels.
• Hypertension: sudden rise in blood pressure.

Precautions should be observed when prescribing Mercilon to ensure safety and effectiveness.

• Smoking: avoid smoking, especially in women over 35, due to heightened thrombotic risk.
• Cardiovascular disease: contraindicated in patients with a history of thromboembolism, myocardial infarction, or stroke.
• Migraine with aura: use with caution as it may increase stroke risk.
• Liver disease: monitor hepatic function and adjust use in severe impairment.
• Pregnancy: contraindicated; product is classified as pregnancy category X.
• Store at ambient temperature: keep below 25 °C, retain in the original packaging, and protect from moisture and light.

Drug interactions may alter the efficacy or safety profile of Mercilon.

Major Interactions (Avoid)

• Antiepileptic enzyme inducers (e.g., carbamazepine, phenytoin): may markedly reduce contraceptive effectiveness.
• Rifampin: decreases hormone levels, increasing the risk of unintended pregnancy.
• Griseofulvin: can lower oral contraceptive efficacy.

Moderate Interactions (Monitor Closely)

• Azole antifungals (e.g., ketoconazole): may increase hormone concentrations, raising side‑effect potential.
• St. John’s wort: may reduce contraceptive effectiveness through enzyme induction.
• Protease inhibitors: can alter hormone metabolism, requiring clinical monitoring.