TRIVORA-21
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TRIVORA-21 (TRIVORA-21).
Combination of ethinyl estradiol and levonorgestrel suppresses gonadotropin release, inhibiting ovulation, altering cervical mucus to impede sperm penetration, and reducing endometrial receptivity to implantation.
| Metabolism | Ethinyl estradiol undergoes first-pass metabolism via CYP3A4 and conjugation (sulfation, glucuronidation) in the liver and intestinal wall. Levonorgestrel is metabolized by reduction, hydroxylation, and conjugation, primarily via CYP3A4. |
| Excretion | Renal (60%), fecal (40%) as metabolites; glucose and sulfate conjugates of ethinyl estradiol and levonorgestrel are excreted in bile and undergo enterohepatic circulation. |
| Half-life | Ethinyl estradiol: terminal half-life 13-27 hours (mean 17 hours); levonorgestrel: terminal half-life 11-45 hours (mean 25 hours). Clinical context: steady-state achieved after 3-5 half-lives (~3-5 days for ethinyl estradiol, ~5-9 days for levonorgestrel). |
| Protein binding | Ethinyl estradiol: 97-98% bound (primarily albumin); levonorgestrel: 97.5-99% bound (sex hormone-binding globulin, SHBG, and albumin). |
| Volume of Distribution | Ethinyl estradiol: 2.5-4.3 L/kg (large volume due to tissue distribution, especially adipose); levonorgestrel: 1.5-2.0 L/kg (distributes to target organs and adipose). |
| Bioavailability | Ethinyl estradiol: 38-48% (oral) due to first-pass metabolism; levonorgestrel: 95-100% (oral) with minimal first-pass effect. |
| Onset of Action | Oral: contraceptive effect begins after 7 consecutive days of administration; immediate if started on day 1 of menstrual cycle. |
| Duration of Action | The contraceptive effect lasts for the duration of the 21-day cycle; after discontinuation, ovulation suppression persists for 1-2 cycles. |
| Molecular Weight | 312.45 |
One tablet orally once daily for 21 days, followed by 7 placebo days.
| Dosage form | TABLET |
| Renal impairment | Contraindicated in severe renal impairment or acute renal failure; no dose adjustment for mild-to-moderate impairment. |
| Liver impairment | Contraindicated in acute or chronic hepatocellular disease with abnormal liver function; use not recommended in Child-Pugh A or B; avoid in Child-Pugh C. |
| Pediatric use | Not indicated for use before menarche; postmenarchal adolescents: same as adult dosing. |
| Geriatric use | Not indicated for use after menopause; no specific geriatric dosing available. |
| 1st trimester | Contraindicated due to risk of congenital defects, particularly cardiovascular and limb defects, associated with sex hormone exposure during organogenesis. |
| 2nd trimester | Contraindicated due to potential adverse effects on fetal development, including masculinization of female fetuses and hepatic adenoma risk. |
| 3rd trimester | Contraindicated due to risk of masculinization of female fetuses and potential for hepatic tumors in the neonate. |
Clinical note
Comprehensive clinical and safety monograph for TRIVORA-21 (TRIVORA-21).
| Placental transfer | Yes, crosses the placenta; detectable in fetal tissues. |
| Breastfeeding | Excreted in breast milk; may cause adverse effects in nursing infants such as jaundice and breast enlargement. Use only if clearly needed and monitor infant. |
■ FDA Black Box Warning
Cigarette smoking increases the risk of serious cardiovascular events from combined hormonal contraceptive use. Risk increases with age and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use this product.
| Serious Effects |
Known or suspected pregnancyBreast cancer (current or history)Undiagnosed abnormal genital bleedingActive hepatic disease or liver tumorsThromboembolic disorders (current or history)Cerebrovascular diseaseCoronary artery disease
| Precautions | Increased risk of venous thromboembolism (VTE) and arterial thrombosis, especially in smokers, obese patients, and those with thrombogenic mutations., Elevated blood pressure risk; monitor in hypertensive patients., Possible increased risk of cervical cancer and breast cancer with long-term use., Hepatic effects: cholestatic jaundice, liver tumors; discontinue if jaundice develops., Exacerbation of gallbladder disease, porphyria, SLE, and hereditary angioedema., Retinal thrombosis; discontinue if unexplained vision loss or proptosis occurs. |
| Food/Dietary | No significant food interactions. Grapefruit juice may slightly increase ethinyl estradiol levels but not clinically relevant. St. John's wort may reduce contraceptive efficacy. |
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| Lactation Rating |
| L4 - Possibly Hazardous |
| Teratogenic Risk | Trivora-21 (levonorgestrel and ethinyl estradiol) is contraindicated in pregnancy. First trimester: Use is associated with a small increase in risk of congenital anomalies, particularly cardiovascular and limb defects, though absolute risk remains low. Second and third trimesters: Exposure may increase risk of fetal hepatic adenoma, adrenal dysfunction, and potential for urogenital abnormalities. No evidence of teratogenicity from inadvertent early exposure, but discontinuation recommended upon pregnancy diagnosis. |
| Fetal Monitoring | Monitor blood pressure, liver function tests (LFTs), and signs of thrombosis. In pregnancy-related use, assess for fetal growth and potential congenital anomalies if inadvertent exposure occurred. No routine fetal monitoring indicated for contraception. |
| Fertility Effects | Suppresses ovulation via inhibition of gonadotropin release. No permanent effect on fertility; return to fertility typically within 1-3 months after discontinuation. May temporarily prolong time to conception. |
| Clinical Pearls | Trivora-21 is a triphasic oral contraceptive containing levonorgestrel and ethinyl estradiol. The varying hormone levels mimic the natural menstrual cycle. Missed pills increase breakthrough bleeding risk. Use backup contraception if pill is taken >3 hours late. Advise patients that initial spotting often resolves after 3 cycles. Smoking ≥15 cigarettes daily in women over 35 is a contraindication due to increased thromboembolic risk. |
| Patient Advice | Take one pill daily at the same time for 21 days, then 7 placebo pills (if included) or 7 pill-free days. · If a pill is missed, follow the package insert instructions: take missed pill immediately if within 12 hours, otherwise skip and use backup contraception. · Common side effects include nausea, breast tenderness, and spotting, which often improve after 2-3 cycles. · Seek immediate medical attention for symptoms of blood clots: leg pain/swelling, sudden chest pain, shortness of breath, severe headache, or vision changes. · Trivora-21 does not protect against HIV or other sexually transmitted infections. |