Mercilon (Desogestrel, Ethinylestradiol)

Mercilon is a combined hormonal contraceptive that acts on the reproductive endocrine system to prevent pregnancy.

• Contraception: provides reliable prevention of pregnancy for women of child‑bearing potential.
• Menstrual cycle regulation: helps establish a more predictable menstrual pattern.
• Acne management: may improve mild to moderate acne associated with hormonal fluctuations.

• Desogestrel is a progestogenic agent that suppresses the mid‑cycle surge of luteinizing hormone (LH) and follicle‑stimulating hormone (FSH), thereby preventing ovulation. Ethinylestradiol provides estrogenic activity that stabilises the endometrial lining and enhances the inhibition of ovulation, while also thickening cervical mucus to impede sperm penetration.

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

Common Side Effects

• Nausea: mild stomach upset, often improves with continued use.
• Headache: tension‑type or migraine‑like pain.
• Breast tenderness: temporary swelling or discomfort.
• Spotting or breakthrough bleeding: irregular bleeding between periods.
• Weight change: slight fluid retention or appetite variation.
• Mood changes: mild irritability or emotional fluctuations.

Serious or Rare Side Effects

• Venous thromboembolism: deep vein thrombosis or pulmonary embolism.
• Arterial thrombosis: stroke or myocardial infarction.
• Hypertension: significant increase in blood pressure.
• Liver dysfunction: jaundice or abnormal liver enzymes.
• Gallbladder disease: gallstones or cholecystitis.
• Severe allergic reaction: rash, swelling, or anaphylaxis.

Before prescribing Mercilon, clinicians should evaluate individual risk factors and contraindications.

• Smoking: avoid use in women over 35 who smoke due to increased thrombotic risk.
• Cardiovascular disease: contraindicated in patients with history of stroke, myocardial infarction, or uncontrolled hypertension.
• Liver disease: use with caution in severe hepatic impairment.
• Migraine with aura: avoid because of elevated stroke risk.
• Pregnancy: discontinue immediately if pregnancy is confirmed.
• Store at ambient temperature: keep below 25 °C, retain original packaging, protect from moisture and direct sunlight.

Mercilon can interact with several medicines that affect its efficacy or safety.

Major Interactions (Avoid)

• Antiepileptic drugs (e.g., carbamazepine, phenytoin): may reduce contraceptive effectiveness.
• Rifampicin and other potent enzyme inducers: can markedly lower hormone levels.
• Certain antivirals (e.g., ritonavir): may increase risk of hormonal side effects.

Moderate Interactions (Monitor Closely)

• Antifungals (e.g., fluconazole): may increase plasma concentrations of ethinylestradiol.
• St. John’s wort: may diminish contraceptive efficacy.
• Diuretics: can affect fluid balance and blood pressure, requiring monitoring.