BLISOVI FE 1/20
Clinical safety rating
cautionComprehensive clinical and safety monograph for BLISOVI FE 1/20 (BLISOVI FE 1/20).
Combination of ethinyl estradiol, an estrogen, and desogestrel, a progestin, which inhibit gonadotropin release (FSH and LH) from the pituitary, suppressing ovulation and altering cervical mucus and endometrial lining to reduce likelihood of fertilization and implantation.
| Metabolism | Ethinyl estradiol is metabolized primarily by CYP3A4; desogestrel is a prodrug converted to etonogestrel, which is metabolized by CYP2C9 and CYP3A4. |
| Excretion | Renal: ~50-60% as metabolites; fecal: ~40-50% via biliary elimination; less than 10% unchanged in urine. |
| Half-life | Ethinyl estradiol: ~12-14 hours; norethindrone: ~7-8 hours; both allow once-daily dosing with steady-state reached within 7-10 days. |
| Protein binding | Ethinyl estradiol: ~97-98% bound (primarily albumin); norethindrone: ~93-95% bound (primarily albumin and SHBG). |
| Volume of Distribution | Ethinyl estradiol: ~2.5-4.0 L/kg; norethindrone: ~3.5-4.5 L/kg; large Vd indicates extensive tissue distribution. |
| Bioavailability | Oral: Ethinyl estradiol ~40-50% (first-pass metabolism); norethindrone ~50-70% (first-pass metabolism reduced with micronized formulation). |
| Onset of Action | Oral: Inhibition of ovulation typically achieved after 7 days of consistent dosing; contraceptive effect begins after 7 days if started on day 1 of menstrual cycle. |
| Duration of Action | Oral: Contraceptive protection persists for 24 hours with once-daily dosing; withdrawal bleeding occurs during the 7-day placebo/iron-free interval. |
| Molecular Weight | 436.4 |
| Action Class | Oral Contraceptive; Estrogen-Progestin Combination |
One tablet orally once daily for 21 days, followed by 7 days of placebo (iron-containing) tablets. Each active tablet contains 0.1 mg levonorgestrel and 20 mcg ethinyl estradiol.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Not studied in severe renal impairment (eGFR <30 mL/min/1.73 m²) or end-stage renal disease; use contraindicated due to potential for fluid retention and hypertension. |
| Liver impairment | Contraindicated in Child-Pugh Class B or C (moderate to severe hepatic impairment) due to reduced steroid clearance. Use with caution in Child-Pugh Class A; monitor liver function. |
| Pediatric use | Use post-menarche. Standard dose: one tablet orally once daily for 21 days, then 7 days of placebo. Not indicated before menarche. |
| Geriatric use | Not indicated for use in postmenopausal women. No specific dose adjustment; efficacy and safety not established in geriatric population. |
| 1st trimester | Contraindicated; risk of congenital defects including neural tube defects and cardiovascular anomalies due to folic acid antagonism. |
| 2nd trimester | Contraindicated; may cause fetal harm including growth restriction and potential teratogenicity. |
| 3rd trimester | Contraindicated; may cause fetal harm and maternal complications including thromboembolism. |
Clinical note
Comprehensive clinical and safety monograph for BLISOVI FE 1/20 (BLISOVI FE 1/20).
| Placental transfer | Crosses the placenta; high transfer rate documented. |
| Breastfeeding | Excreted in breast milk; may cause jaundice and hemolytic anemia in neonates. Use is generally avoided during breastfeeding. |
| Lactation Rating | L5 - Contraindicated |
| Teratogenic Risk | Tri 1: No increased risk of birth defects in large cohort studies; however, combined hormonal contraceptives are contraindicated in pregnancy due to potential fetal harm from estrogen. Tri 2 & 3: No known teratogenicity; continuation after confirmed pregnancy not indicated. |
| Fetal Monitoring | Pregnancy test at baseline and if pregnancy suspected; no routine fetal monitoring required. Monitor blood pressure and thromboembolic signs if pregnancy occurs. |
| Fertility Effects | Reversible inhibition of ovulation; normal fertility returns after discontinuation. No permanent effects on fertility. |
■ FDA Black Box Warning
Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age and number of cigarettes smoked, particularly in women over 35 years old.
| Common Effects | Nausea, Headache, Breast tenderness, Irregular uterine bleeding, Weight changes, Mood changes |
| Serious Effects | Venous thromboembolism (VTE), Arterial thromboembolism (e.g., stroke, myocardial infarction), Hypertension, Hepatic adenoma or hepatocellular carcinoma, Gallbladder disease, Hyperkalemia (due to drospirenone's antimineralocorticoid activity) |
Pregnancy or suspected pregnancyHistory of thromboembolic disordersCerebrovascular or coronary artery diseaseKnown or suspected breast cancerUndiagnosed abnormal uterine bleedingCholestatic jaundice of pregnancy or jaundice with prior pill useHepatic adenomas or carcinomasKnown hypersensitivity to ethinyl estradiol or norethindrone
| Precautions | Increased risk of venous thromboembolism and arterial thrombosis, Increased risk of myocardial infarction and stroke, especially in smokers, Liver disease including hepatic adenoma and hepatocellular carcinoma, Hypertension, Gallbladder disease, Carbohydrate and lipid metabolism effects, Headache including migraine, Uterine bleeding irregularities, Depression, Hereditary angioedema, Chloasma, Ocular lesions (e.g., retinal thrombosis) |
| Food/Dietary | No specific food restrictions. May be taken with or without food. Grapefruit juice may increase ethinyl estradiol levels but not clinically significant. Avoid St. John's wort (reduces efficacy). Alcohol consumption is not contraindicated but may increase side effects like nausea or dizziness. |
| Clinical Pearls | BLISOVI FE 1/20 is a combination oral contraceptive containing norethindrone acetate (1 mg) and ethinyl estradiol (20 mcg) with ferrous fumarate (75 mg) as an iron supplement in the placebo pills. The low estrogen dose may increase breakthrough bleeding risk, especially in the first few cycles. The ferrous fumarate tablets are not intended for contraceptive effect; ensure patients take active pills correctly. Missed pill management: if one active pill is missed, take as soon as remembered; if two or more active pills are missed, use backup contraception for 7 days and consider emergency contraception. Active pill color is pink; placebo pills are brown (ferrous fumarate). Contraindications: history of thromboembolic events, migraine with aura, liver disease, undiagnosed abnormal uterine bleeding, breast cancer, or pregnancy. Monitor for hypertension, depression, and cholestasis. Drug interactions: CYP3A4 inducers (e.g., rifampin, phenytoin, carbamazepine, St. John's wort) reduce efficacy; antibiotics may also reduce efficacy (except rifampin-like drugs, which are definite). |
| Patient Advice | Take one pill daily at the same time, preferably in the evening to reduce nausea. · The pill pack contains 21 active pink pills (hormonal) and 7 brown placebo pills (contain iron). · You will have a withdrawal bleed during the placebo week, typically starting 2-3 days after the last active pill. · If you miss a dose, refer to the package instructions: for one missed active pill, take it as soon as remembered; if more than one missed, use a backup method for 7 days. · Inform your healthcare provider if you experience severe abdominal pain, chest pain, shortness of breath, headache, visual changes, or leg pain/swelling. · Smoking increases the risk of serious cardiovascular side effects; avoid smoking, especially if over 35 years old. · This medication does not protect against sexually transmitted infections; use condoms for prevention. · The iron in placebo pills may cause dark stools; this is harmless. · Store at room temperature away from moisture and heat. |
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