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. |
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 | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for TYBLUME (TYBLUME).
| Breastfeeding | Data on breastfeeding exposure are limited. Norethindrone (the active progestin) is excreted in human milk in small amounts. The M/P ratio is unknown. The American Academy of Pediatrics considers norethindrone compatible with breastfeeding, but long-term effects on the infant are unknown. Use during lactation is not recommended unless the expected benefit outweighs potential risks. Monitor infant for jaundice, drowsiness, and weight gain. |
| 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. |
■ 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 |
["History of or current venous thromboembolism","High risk of venous or arterial thrombosis","Cerebrovascular disease","Coronary artery disease","Uncontrolled hypertension","Diabetes with vascular involvement","Headaches with focal neurological symptoms or migraine with aura (age ≥35)","Undiagnosed abnormal uterine bleeding","Current or history of breast cancer or other estrogen-sensitive neoplasia","Liver tumors (benign or malignant) or active liver disease","Use of Hepatitis C combination therapy containing ombitasvir/paritaprevir/ritonavir ± dasabuvir","Pregnancy","Hypersensitivity to any component","Age >35 and smoking ≥15 cigarettes/day"]
| 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"] |
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| 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. |