TYBLUME
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TYBLUME (TYBLUME).
Combination of norethindrone acetate, a progestin, and ethinyl estradiol, an estrogen, that suppresses gonadotropin release, preventing ovulation and altering cervical mucus and endometrial lining.
| Metabolism | Metabolized primarily by cytochrome P450 3A4 (CYP3A4) in the liver; norethindrone undergoes reduction and conjugation; ethinyl estradiol is metabolized by CYP3A4 and undergoes glucuronidation. |
| Excretion | Approximately 50% to 60% is excreted in urine as unchanged drug and metabolites, with the remainder eliminated in feces via biliary excretion. Renal clearance accounts for 30-40% of total clearance, and fecal elimination for 20-30%. |
| Half-life | The terminal elimination half-life is approximately 20 to 30 hours in healthy adults, allowing once-daily dosing. In patients with hepatic impairment, the half-life may be prolonged up to 40 hours. |
| Protein binding | Approximately 98% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | The volume of distribution is approximately 0.6 to 0.8 L/kg, suggesting distribution into total body water and moderate tissue binding. |
| Bioavailability | Oral bioavailability is approximately 80% to 90% under fasting conditions. Food does not significantly alter the extent of absorption, but may delay Tmax by 1-2 hours. |
| Onset of Action | Following oral administration, the onset of therapeutic effect is observed within 1 to 2 hours, with peak plasma concentrations reached in 2 to 4 hours. |
| Duration of Action | The duration of action is approximately 24 hours, supporting once-daily administration. Clinical effects persist for the dosing interval, with steady-state achieved after 5-7 days of repeated dosing. |
| Molecular Weight | 294.34 |
1 tablet (0.1 mg levonorgestrel/0.02 mg ethinyl estradiol) orally once daily for 24 days, then 1 inert tablet for 2 days.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required in mild to moderate renal impairment. Not studied in severe renal impairment; use contraindicated if renal function is severely compromised due to potential for hormonal accumulation. |
| Liver impairment | Contraindicated in severe hepatic disease (Child-Pugh class C). Use with caution and monitor liver function in mild to moderate impairment (Child-Pugh A or B); dose adjustment not specifically defined. |
| Pediatric use | Not indicated for use before menarche. For postmenarchal adolescents, dosing is same as adult: 1 tablet daily for 24 days followed by 2 inert tablets. Safety and efficacy established in females of reproductive age. |
| Geriatric use | Not indicated for use after menopause. For perimenopausal women, same dosing as adult, but use caution due to increased risk of thromboembolic events and cardiovascular disease in older women. |
| 1st trimester | Contraindicated due to risk of fetal malformations, including heart defects and neural tube defects. |
| 2nd trimester | Contraindicated; may cause fetal harm based on human data. |
| 3rd trimester | Contraindicated; may cause neonatal withdrawal and respiratory depression. |
Clinical note
Comprehensive clinical and safety monograph for TYBLUME (TYBLUME).
| Placental transfer | Crosses the placenta; documented in human studies. |
| Breastfeeding | Not recommended during breastfeeding. Small amounts may be excreted in breast milk; potential for serious adverse reactions in nursing infants. |
| Lactation Rating |
■ FDA Black Box Warning
Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptive use. This risk increases with age and with heavy smoking (≥15 cigarettes per day) and is quite marked in women over 35 years of age. Women who use combination hormonal contraceptives should be strongly advised not to smoke.
| Serious Effects |
PregnancyBreastfeedingHypersensitivity to drug or any componentConcurrent use of MAOIs or within 14 days of MAOI discontinuationUncontrolled narrow-angle glaucomaSevere hepatic impairment
| Precautions | Thrombotic events including venous thromboembolism and arterial thrombotic events, Cardiovascular disease risk in smokers, Elevated blood pressure, Gallbladder disease, Hepatic impairment, Carbohydrate and lipid metabolic effects, Headache/migraine, Bleeding irregularities, Use in pregnancy, Depression, Malignant neoplasms, Ocular lesions, Hereditary angioedema, Chloasma, Interference with laboratory tests |
| Food/Dietary | No significant food interactions. Grapefruit juice may increase estrogen levels by inhibiting CYP3A4, but this is not specific to TYBLUME. Avoid St. John's wort as it may reduce contraceptive efficacy. |
Loading safety data…
| L5 - Avoid |
| Teratogenic Risk | Pregnancy Category X. Contraindicated in pregnancy. No adequate studies in pregnant women. Fetal risk is based on animal studies and known teratogenic effects of progestins in early pregnancy, including genital abnormalities (masculinization of female fetuses) and increased risk of neural tube defects, cardiac defects, and limb defects. Use during first trimester is associated with a significantly increased risk of spontaneous abortion and fetal malformations. Second and third trimester exposure may result in adverse fetal outcomes such as low birth weight, neonatal withdrawal syndrome, and endocrine disturbances. |
| Fetal Monitoring | Monitor pregnancy status before initiating therapy (rule out pregnancy). During use, perform pregnancy tests if pregnancy is suspected. For women who become pregnant during therapy, discontinue immediately and advise regarding fetal risks. Consider ultrasound for fetal assessment if inadvertent exposure occurs. No specific maternal monitoring is required beyond routine prenatal care. |
| Fertility Effects | TYBLUME is a progestin-only contraceptive. It is intended to prevent pregnancy. After discontinuation, return to fertility is expected to be rapid, typically within the first menstrual cycle. No long-term effects on fertility have been reported. |
| Clinical Pearls | TYBLUME is a combined oral contraceptive containing levonorgestrel and ethinyl estradiol. It is indicated for the prevention of pregnancy. Note that it is a 91-day extended-cycle regimen (84 active pills followed by 7 placebo pills). The progestin component is a first-generation progestin. Monitor for thromboembolic events, especially in smokers over 35. Breakthrough bleeding is common in the first few cycles. |
| Patient Advice | Take one pill daily at the same time each day to maintain contraceptive efficacy. · Expect spotting or breakthrough bleeding during the first few cycles; this typically decreases with continued use. · Use backup contraception (e.g., condoms) for the first 7 days of the first pack if not starting on the first day of menstruation. · If you miss a pill, follow the package instructions carefully; if you miss more than 2 pills, use backup contraception. · This regimen has 84 active pills followed by 7 placebo pills; you will have a period only during the placebo week every 3 months. |