A combined birth control pill with a progestin (levonorgestrel) and an estrogen (ethinyl estradiol), taken every day to prevent pregnancy. It works mainly by stopping ovulation, and smoking raises its risk of heart attack, stroke, and blood clots, especially after age 35.
Labeled use. Prevention of pregnancy in females of reproductive potential.
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A low-dose levonorgestrel combined pill is a common first choice for women who want a daily, reversible method and have no estrogen contraindications, and levonorgestrel is linked to a lower VTE risk than some newer progestins. Progestin-only methods, a copper or levonorgestrel IUD, or the implant are preferred for smokers over 35, migraine with aura, high clot risk, uncontrolled hypertension, or early breastfeeding. IUDs and the implant are more effective in typical use because they do not depend on daily pills. Tyblume's chewable tablet may suit people who have trouble swallowing pills.
A combined hormonal contraceptive: levonorgestrel, a progestin, plus ethinyl estradiol, an estrogen. CHCs prevent pregnancy mainly by suppressing ovulation. Levonorgestrel is about 100% bioavailable with no first-pass metabolism; ethinyl estradiol bioavailability is 38% to 48% because of gut-wall and hepatic first pass, and CYP3A4 2-hydroxylation is its main oxidative pathway. Steady-state half-lives are about 36 hours for levonorgestrel and 18 hours for ethinyl estradiol.
The label does not describe a narrow therapeutic index or direct dosing by measured blood levels of the drug.
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Doses come from the FDA label. Study tool, not for clinical decisions.
No renal dose adjustment on the label. Levonorgestrel and its metabolites are excreted mostly in the urine, and ethinyl estradiol in urine and feces as conjugates.
Not studied in hepatic impairment, and steroid hormones may be poorly metabolized when the liver is impaired. Contraindicated with liver tumors, acute viral hepatitis, or decompensated cirrhosis. Stop for jaundice or acute liver test abnormalities until they return to normal and the pill is excluded as the cause.
Cigarette smoking and serious cardiovascular events. Smoking raises the risk of serious cardiovascular events from combined hormonal contraceptives, and the risk climbs with age, especially over 35, and with the number of cigarettes smoked. Tyblume is contraindicated in women over 35 who smoke.
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No antidote. Overdose may cause nausea and uterine bleeding; give supportive care.
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There is no use for a contraceptive in pregnancy, so stop it once pregnancy is confirmed. Epidemiologic studies and meta-analyses have not found more genital or other birth defects after exposure before conception or in early pregnancy.
Small amounts of the hormones or their metabolites pass into milk, and a few infant effects such as jaundice and breast enlargement have been reported. Combined pills can reduce milk supply, which is less likely once breastfeeding is well established, so advise another method until weaning when possible.
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Safety and effectiveness are established in females of reproductive potential, and efficacy is expected to be the same in post-menarchal females under 17 as in those 17 and older. Not indicated before menarche.
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