1. Clinical Overview
A low-dose, biphasic combined oral contraceptive (COC) pill containing a synthetic estrogen (Ethinyl Estradiol) and a second-generation progestin (Levonorgestrel). It is a widely used, highly effective, and reversible method of contraception in the Indian market. It works primarily by inhibiting ovulation, thickening cervical mucus, and altering the endometrium.
| Onset | Duration | Bioavailability |
|---|---|---|
| Contraceptive effect begins immediately if started on day 1-5 of the menstrual cycle. Cervical mucus changes occur within hours; ovulation inhibition requires consistent use over 7 days. | 24-hour contraceptive coverage per dose. Must be taken daily for continuous efficacy. | Ethinyl Estradiol: ~40-50% (extensive first-pass metabolism). Levonorgestrel: ~100% (almost completely bioavailable). |
2. Mechanism of Action
The combination exerts a synergistic contraceptive effect through multiple mechanisms: 1) Inhibition of the mid-cycle gonadotropin surge (LH and FSH) from the pituitary, preventing ovulation. 2) Production of a thick, viscous cervical mucus hostile to sperm penetration and capacitation. 3) Induction of endometrial atrophy, making it unsuitable for implantation.
3. Indications & Uses
- Prevention of pregnancy (Contraception)
- Regulation of menstrual cycle (for women with irregular cycles on COC)
4. Dosage & Administration
Adult Dosage: One tablet orally, once daily, at approximately the same time each day. Standard regimen: 21 active tablets followed by a 7-day hormone-free interval (or 7 placebo pills). For 28-day packs, follow pack instructions.
Administration: Take with or without food. If gastrointestinal upset occurs, take with food. Start on Day 1 of menstrual cycle (no backup needed) or on Sunday after period begins (backup contraception needed for first 7 days). For postpartum (non-breastfeeding), start at 4 weeks. For post-abortion, start immediately. If a pill is missed, refer to specific missed pill guidelines (within 12-24 hours).
5. Side Effects
Common side effects may include:
- Nausea, vomiting
- Headache (including migraine)
- Breast tenderness, enlargement
- Breakthrough bleeding, spotting (especially in first 3 cycles)
- Amenorrhea or changes in menstrual flow
- Mood changes, depression
- Weight change
- Acne (may improve or worsen initially)
- Decreased libido
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Enzyme Inducers (e.g., Rifampicin, Rifabutin, Carbamazepine, Phenytoin, Phenobarbital, Primidone, Topiramate, Modafinil, St. John's Wort) | Marked decrease in Ethinyl Estradiol and Levonorgestrel plasma levels, leading to contraceptive failure and breakthrough bleeding. | Major |
| Broad-spectrum Antibiotics (e.g., Ampicillin, Tetracyclines, Griseofulvin) | Possible reduction in contraceptive efficacy due to altered gut flora and reduced enterohepatic recirculation of EE. | Moderate |
| Antiretroviral Protease Inhibitors & NNRTIs (e.g., Ritonavir, Efavirenz) | Variable effects; some increase, some decrease hormone levels. Consult specific guidelines. | Major |
| Ascorbic Acid (High Dose), Atorvastatin | May increase Ethinyl Estradiol plasma levels. | Minor |
| Warfarin, other Coumarins | Ethinyl Estradiol may decrease anticoagulant effect; monitor INR closely. | Moderate |
| Cyclosporine | Ethinyl Estradiol may increase Cyclosporine levels, risk of toxicity. | Moderate |
| Lamotrigine | Ethinyl Estradiol significantly reduces Lamotrigine levels, increasing seizure risk. | Major |
| Tizanidine | Ethinyl Estradiol may potentiate hypotensive and sedative effects. | Moderate |
7. Patient Counselling
- DO take the pill at the same time every day to maintain efficacy.
- DO use a backup contraceptive method (e.g., condoms) for the first 7 days of the first cycle or if you miss a pill.
- DO inform all healthcare providers (including dentists) that you are on oral contraceptives.
- DONT smoke cigarettes, especially if you are over 35.
- DONT take new medications (including OTC, herbal like St. John's Wort) without consulting your doctor/pharmacist.
- DONT use this pill to protect against HIV/AIDS or other STIs.
8. Toxicology & Storage
Overdose: Nausea, vomiting, withdrawal bleeding in females. No specific acute life-threatening symptoms in adults. In children, estrogen overdose may cause nausea and gynecomastia.
Storage: Store below 30°C, in a cool, dry place, protected from light and moisture. Keep out of reach of children. Do not use after the expiry date printed on the pack.