Microdiol (Desogestrel, Ethinylestradiol)

Microdiol is a combined oral contraceptive that acts on the hormonal regulation of the menstrual cycle.

• Contraception (prevention of pregnancy): provides reliable birth control for women of reproductive age.
• Menstrual cycle regulation: helps establish a more predictable menstrual pattern.
• Treatment of moderate acne: reduces androgen‑driven skin lesions in eligible patients.

• Desogestrel is a progestogenic agent that suppresses the mid‑cycle luteinising hormone surge, preventing ovulation. Ethinylestradiol provides estrogenic activity that stabilises the endometrium and enhances the progestin's effect on cervical mucus, making it thicker and less permeable to sperm, thereby inhibiting fertilisation and implantation.

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

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Headache: tension‑type or migraine‑like pain.
• Breast tenderness: temporary swelling or discomfort.
• Spotting or breakthrough bleeding: irregular light bleeding.
• Weight gain: modest fluid retention.
• Mood changes: irritability or mild depression.

Serious or Rare Side Effects

• Venous thromboembolism: deep‑vein thrombosis or pulmonary embolism.
• Arterial thrombosis: stroke or myocardial infarction.
• Severe hypertension: sudden increase in blood pressure.
• Liver dysfunction: jaundice or abnormal liver enzymes.
• Gallbladder disease: cholelithiasis or cholecystitis.
• Allergic reaction: rash, swelling, or anaphylaxis.

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

• Smoking: avoid use in women over 35 who smoke due to increased cardiovascular risk.
• History of thromboembolism: contraindicated in patients with prior clotting events.
• Hypertension: monitor blood pressure regularly.
• Liver disease: use with caution in patients with active liver pathology.
• Migraine with aura: consider alternative contraception.
• Store at ambient temperature: keep below 25 °C, in the original packaging, protected from moisture and direct sunlight.

Microdiol can interact with several medicines that affect hormone metabolism or clotting risk.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampicin, carbamazepine): markedly reduce contraceptive efficacy.
• Anticoagulants (e.g., warfarin): may increase bleeding risk.
• Certain antiretrovirals (e.g., protease inhibitors): can alter hormone levels.

Moderate Interactions (Monitor Closely)

• Antifungals (e.g., ketoconazole): may increase hormone concentrations.
• Antidepressants (e.g., sertraline): potential for modest pharmacokinetic changes.
• Herbal supplements (e.g., St John’s wort): may reduce effectiveness.
• Diuretics: may affect fluid balance and blood pressure.