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.
Hormonal contraceptives are not on the ISMP acute care high-alert list.
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The label does not describe a narrow therapeutic index or direct dosing by measured blood levels of the drug.
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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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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.
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.