Iren 28 (Drospirenone, Ethinylestradiol | Lactose Anhydrous)

Iren 28, a combined oral contraceptive, is indicated for hormonal contraception to prevent pregnancy.

• Prevention of pregnancy: provides reliable contraceptive protection for women of childbearing potential.
• Regulation of menstrual cycle: helps achieve more predictable bleeding patterns and may reduce menstrual flow.
• Treatment of moderate acne: may improve acne related to androgen excess in women.
• Management of premenstrual syndrome: may alleviate mood swings and physical symptoms associated with PMS.

• Drospirenone is a synthetic progestogen with anti‑mineralocorticoid and anti‑androgenic activity, while ethinylestradiol is a synthetic estrogen. Together they bind to progesterone and estrogen receptors, suppressing the hypothalamic‑pituitary‑ovarian axis, preventing the mid‑cycle surge of luteinizing hormone and thus ovulation. They also thicken cervical mucus and alter the endometrium, creating an environment unfavorable for fertilization and implantation.

Iren 28 may cause a range of adverse reactions, which are classified by frequency and severity.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Breast tenderness: discomfort or swelling of the breasts.
• Headache: occasional throbbing or tension‑type pain.
• Spotting between periods: light vaginal bleeding.

Serious or Rare Side Effects

• Deep vein thrombosis: blood clot formation in deep veins, potentially life‑threatening.
• Pulmonary embolism: clot migration to lungs causing respiratory distress.
• Severe allergic reaction: rash, swelling, or anaphylaxis requiring immediate medical attention.

Before prescribing Iren 28, clinicians should consider several precautionary measures to ensure patient safety.

• Contraindications: avoid use in women with a history of thromboembolic disorders, estrogen‑dependent tumors, or active liver disease.
• Smoking: do not prescribe to smokers over 35 years of age due to increased cardiovascular risk.
• Cardiovascular risk: assess blood pressure and lipid profile before initiating therapy.
• Drug interactions: review concomitant medications that may affect clotting or hormone metabolism.
• Pregnancy and lactation: discontinue if pregnancy is confirmed and avoid use during breastfeeding unless benefits outweigh risks.
• Store at ambient temperature: keep below 25 °C in the original packaging, protect from moisture and light.

Iren 28 can interact with other medicines, altering its effectiveness or increasing the risk of adverse events.

Major Interactions (Avoid)

• Combined hormonal contraceptives with other estrogen‑containing products: may increase risk of thrombosis.
• Certain antiepileptic drugs (e.g., carbamazepine, phenytoin): can reduce hormonal levels, decreasing contraceptive efficacy.
• Strong CYP3A4 inducers (e.g., rifampicin, St. John’s wort): may markedly lower ethinylestradiol concentrations.

Moderate Interactions (Monitor Closely)

• Antifungal azoles (e.g., ketoconazole): may increase hormone levels, raising side‑effect risk.
• Antibiotics such as metronidazole: may slightly affect contraceptive reliability; advise backup contraception.