A 28-year-old nulliparous woman with a history of irregular, heavy periods and no structural uterine pathology on imaging presents for management. She requires contraception and has failed medical management with tranexamic acid. What is the drug of choice for her condition?

Explanation

## Second-Line Management: Heavy Menstrual Bleeding with Contraceptive Need **Key Point:** The levonorgestrel intrauterine system (LNG-IUS) is the drug of choice for heavy menstrual bleeding when contraception is also required and first-line pharmacotherapy has failed. ### Mechanism of Action The LNG-IUS releases levonorgestrel directly into the uterine cavity, causing: 1. Endometrial atrophy and thinning 2. Suppression of endometrial prostaglandin synthesis 3. Local anti-inflammatory effects 4. Systemic progestin effect for contraception ### Efficacy & Advantages | Parameter | LNG-IUS | DMPA | COC | Danazol | |-----------|---------|------|-----|----------| | **Blood loss reduction** | 80–90% | 50–70% | 30–50% | 80–90% | | **Contraceptive efficacy** | 99.8% | 99.7% | 91% | No | | **Amenorrhea rate** | 20% at 1 year | 40–50% | Variable | 50–80% | | **Suitable for nullipara** | Yes | Yes | Yes | No | | **Androgenic side effects** | None | None | None | Yes (virilization) | | **Duration of action** | 5 years | 3 months | Continuous | Continuous | **High-Yield:** The LNG-IUS is superior to oral contraceptives for menorrhagia because it delivers progestin directly to the endometrium, achieving greater blood loss reduction (80–90% vs 30–50%) with lower systemic hormone exposure. ### Clinical Pearl The LNG-IUS is particularly advantageous in: - Nulliparous women (contrary to older dogma, it is safe and effective) - Women who fail or cannot tolerate first-line agents - Those requiring both contraception and menorrhagia treatment - Women with contraindications to estrogen (thrombophilia, migraine with aura) ### Timeline to Efficacy - **Contraceptive protection:** Immediate (if inserted within 7 days of cycle onset) - **Reduction in bleeding:** Progressive over 3–6 months - **Maximum effect:** By 12 months ### Why Not Other Options? **Medroxyprogesterone Acetate (DMPA) Injection:** - Achieves 50–70% reduction in blood loss (less than LNG-IUS) - Higher rates of irregular bleeding and spotting initially - Amenorrhea develops in 40–50% (not ideal if patient wants regular cycles) - Less effective than LNG-IUS for menorrhagia **Combined Oral Contraceptive Pill (COC):** - Reduces blood loss by only 30–50% (significantly less than LNG-IUS) - Requires daily compliance - Not ideal for women who have failed first-line pharmacotherapy - Contraindicated if migraine with aura or thrombophilia present **Danazol:** - Synthetic androgen; effective (80–90% reduction) but causes significant virilization - Side effects: acne, hirsutism, voice deepening, clitoral enlargement - Hepatotoxicity risk with prolonged use - No contraceptive benefit - Rarely used in modern practice; reserved only for severe, refractory cases [cite:Jeffcoate's Principles of Gynaecology 8e Ch 15] [cite:RCOG Guideline on Heavy Menstrual Bleeding 2016]