BLISOVI 24 FE
Clinical safety rating
cautionComprehensive clinical and safety monograph for BLISOVI 24 FE (BLISOVI 24 FE).
Combination of ethinyl estradiol and drospirenone; primarily suppresses gonadotropins (FSH, LH) via negative feedback, preventing ovulation. Drospirenone has anti-mineralocorticoid and anti-androgenic activity.
| Metabolism | Ethinyl estradiol undergoes hydroxylation via CYP3A4 and conjugation (glucuronidation, sulfation); drospirenone is metabolized primarily via CYP3A4 and to a lesser extent via CYP1A1 and CYP2C9. |
| Excretion | Renal: 30-40% as drospirenone metabolites, 20-30% as ethinyl estradiol metabolites; fecal: 40-50% as drospirenone metabolites, 30-40% as ethinyl estradiol metabolites; biliary: minimal. |
| Half-life | Drospirenone: 25-33 hours; Ethinyl estradiol: 13-24 hours; steady-state achieved after 10 days. |
| Protein binding | Drospirenone: 95-97% bound to albumin; Ethinyl estradiol: 98% bound to albumin and SHBG. |
| Volume of Distribution | Drospirenone: 4 L/kg; Ethinyl estradiol: 2-4 L/kg; indicates extensive tissue distribution. |
| Bioavailability | Oral: Drospirenone ~76%; Ethinyl estradiol ~45% (first-pass metabolism reduces absolute bioavailability). |
| Onset of Action | Oral: contraception effect begins after 7 days of continuous dosing; therapeutic effect on acne/PMDD may require 1-3 cycles. |
| Duration of Action | Oral: 24-hour dosing interval; contraceptive protection lasts through 4-day placebo interval if taken correctly. |
| Molecular Weight | 252.31 |
| Action Class | Oral Contraceptive; Progestin-Estrogen Combination |
One tablet orally once daily for 24 weeks, followed by placebo tablets for 4 weeks; each tablet contains 0.15 mg levonorgestrel and 0.03 mg ethinyl estradiol for 21 days, then 0.01 mg ethinyl estradiol for 3 days, then 2 tablets of 75 mg ferrous fumarate for 5 days.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment (GFR <30 mL/min/1.73 m²) due to potential fluid and electrolyte disturbances. |
| Liver impairment | Contraindicated in acute hepatic disease, hepatic adenomas, or impaired liver function (Child-Pugh class B or C). For mild hepatic impairment (Child-Pugh A), use with caution and monitor liver function; dose adjustment not specifically defined. |
| Pediatric use | Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults: one tablet orally once daily for 24 weeks followed by placebo for 4 weeks. |
| Geriatric use | Not indicated for use in postmenopausal women. No specific geriatric dose studies; use not recommended in elderly due to lack of indication. |
| 1st trimester | Contraindicated due to risk of fetal malformations, particularly cardiac and neural tube defects, if pregnancy occurs during use. Monotherapy if inadvertently used. |
| 2nd trimester | Contraindicated; increased risk of fetal toxicity, including IUGR and craniofacial defects. |
| 3rd trimester | Contraindicated; neonatal hemorrhage and withdrawal symptoms may occur. Avoid labor and delivery use. |
Clinical note
Comprehensive clinical and safety monograph for BLISOVI 24 FE (BLISOVI 24 FE).
| Placental transfer | Crosses placenta; fetal concentrations reach 50-100% of maternal levels. |
| Breastfeeding | Excreted in breast milk; may cause infant drowsiness and poor feeding. Use with caution; monitor for adverse effects. Consider alternative therapy if high doses required. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | BLISOVI 24 FE (norethindrone/ethinyl estradiol) is contraindicated in pregnancy due to increased risk of fetal harm, including cardiovascular anomalies and neural tube defects during first trimester. No evidence of teratogenicity from inadvertent exposure, but risk of oral clefts and heart defects with first trimester use. Later trimester exposure may be associated with genitourinary anomalies and potentially metabolic effects. |
| Fetal Monitoring | Perform rule-out pregnancy test before initiation. Monitor for hypertension, thromboembolic events, and liver dysfunction. Fetal surveillance includes growth scans if exposure occurs. Blood pressure every 3 months; annual liver function tests. |
| Fertility Effects | Suppresses ovulation via gonadotropin inhibition. Reversible upon discontinuation; no permanent fertility impairment after cessation. May cause delayed return of fertility for up to 3 months. |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptives (COCs). Risk increases with age (especially in women >35 years) and with number of cigarettes smoked. Women over 35 who smoke should not use COCs.
| Common Effects | Nausea, Headache, Breast tenderness, Irregular bleeding or spotting, 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) |
PregnancyKnown hypersensitivity to zonisamide or sulfonamidesSevere hepatic impairment
| Precautions | Thrombotic disorders and cardiovascular events (including VTE, MI, stroke), Liver disease (including hepatic adenoma or active hepatitis), Hypertension (especially new-onset or uncontrolled), Carbohydrate and lipid metabolism effects, Headache (including migraine with focal neurological symptoms), Bleeding irregularities (e.g., breakthrough bleeding, amenorrhea), Depression, Gallbladder disease, Hereditary angioedema exacerbation, Chloasma, Drug interactions (e.g., anticonvulsants, antibiotics, St. John's Wort) |
| Food/Dietary | No specific food interactions. Grapefruit juice may increase estrogen levels, but clinical significance is not established. The iron tablets should be taken with food if gastrointestinal upset occurs; avoid taking with calcium-rich foods or beverages (e.g., milk) as they may reduce iron absorption. |
| Clinical Pearls | BLISOVI 24 FE is a combination oral contraceptive containing drospirenone and ethinyl estradiol, with ferrous fumarate as an iron supplement in the fourth week. The drospirenone component has anti-mineralocorticoid activity, which may cause mild potassium elevation; caution in patients with renal impairment or on potassium-sparing diuretics. Missed pills in week 1 warrant a backup method. The iron tablets are placebo for contraception; ensure patient does not mistake them for active pills. |
| Patient Advice | Take one pill daily at the same time. The last 4 tablets in the pack are iron tablets, not active hormones; they do not provide contraception. · If you miss one active pill, take it as soon as remembered and continue the pack. If you miss two active pills in a row, take the last missed pill, discard the other, use backup contraception for 7 days. · Smoking increases risk of serious cardiovascular side effects, especially in women over 35. Avoid smoking while on this medication. · Inform your healthcare provider if you have kidney disease, liver disease, adrenal insufficiency, or if you take potassium-sparing diuretics (e.g., spironolactone) due to potential potassium elevation. · Common side effects include nausea, breast tenderness, headache, and spotting between periods. These often improve after a few cycles. |
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