FEMCON FE

Clinical safety rating: caution

Comprehensive clinical and safety monograph for FEMCON FE (FEMCON FE).

How it works

Combination oral contraceptive containing norethindrone and ethinyl estradiol. Inhibits ovulation via suppression of gonadotropins (FSH, LH); increases cervical mucus viscosity, impairing sperm penetration; alters endometrial receptivity.

What the body does with it

Metabolism	Norethindrone is metabolized primarily via reduction and sulfate conjugation; ethinyl estradiol is metabolized via CYP3A4 and glucuronidation.
Excretion	Renal excretion accounts for approximately 40-60% of the dose as metabolites; fecal excretion is about 20-30% via bile. Unchanged drug excretion is minimal.
Half-life	The terminal elimination half-life of ethinyl estradiol is 13-18 hours; for norethindrone, it is 7-12 hours. Both allow once-daily dosing for contraceptive efficacy.
Protein binding	Ethinyl estradiol is approximately 98% bound to albumin and sex hormone-binding globulin (SHBG); norethindrone is about 80% bound to albumin and SHBG.
Volume of Distribution	Ethinyl estradiol: 2.3-4.1 L/kg; norethindrone: 3.6-4.5 L/kg. Indicates extensive tissue distribution, including reproductive tissues.
Bioavailability	Oral bioavailability: ethinyl estradiol ~40-45% (due to first-pass metabolism); norethindrone ~60-80%. Ferrous fumarate (iron supplement) has low bioavailability but is not relevant for contraception.
Onset of Action	Contraceptive effect begins after 7 consecutive days of active pills when taken correctly. Ovulation suppression may occur earlier.
Duration of Action	Duration of contraceptive effect lasts throughout the 21-day active pill cycle; after last active pill, effects wane over 5-7 days, leading to withdrawal bleed. Missed pills risk ovulation.

Classification & Brands

Dosing & administration

One tablet (norethindrone 0.5 mg + ethinyl estradiol 35 mcg) orally once daily for 28 days.

Dosage form	TABLET
Renal impairment	No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment due to potential estrogen accumulation.
Liver impairment	Contraindicated in severe hepatic disease (Child-Pugh class C). Use with caution in Child-Pugh class A or B; consider alternative contraception.
Pediatric use	Not indicated for use before menarche. Post-menarche: same as adult dosing (one tablet daily).
Geriatric use	Not indicated for use in postmenopausal women. No dose adjustment required for healthy elderly; consider risks of thromboembolism and metabolic effects.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for FEMCON FE (FEMCON FE).

Breastfeeding	Contraindicated in breastfeeding. Excreted in breast milk; may suppress milk production and cause adverse effects in nursing infants (e.g., jaundice, breast enlargement). M/P ratio not established; ethinyl estradiol and norethindrone acetate are present in low levels. Use alternative contraception.
Teratogenic Risk	FDA Pregnancy Category X. Contraindicated in pregnancy due to known teratogenicity. First trimester exposure is associated with cardiovascular defects, neural tube defects, and limb reduction defects. Second and third trimester exposure carries risks of fetal genital abnormalities (e.g., virilization of female fetuses from progestin component).

Warnings & precautions

■ FDA Black Box Warning

Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age (>35 years) and number of cigarettes smoked. Women who use combination oral contraceptives should be strongly advised not to smoke.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Thrombophlebitis or thromboembolic disorders","History of deep vein thrombosis or pulmonary embolism","Cerebrovascular or coronary artery disease","Known or suspected breast cancer","Undiagnosed abnormal genital bleeding","Known or suspected pregnancy","Benign or malignant liver tumor","Active liver disease or impaired liver function","Hypersensitivity to any component",">35 years and smokes ≥15 cigarettes per day"]

Clinical Precautions

Precautions

["Thrombotic disorders (venous thromboembolism, stroke, MI)","Cardiovascular disease (especially in smokers >35 years)","Hepatic neoplasia","Gallbladder disease","Hypertension","Carbohydrate/lipid effects","Headache/migraine","Uterine bleeding irregularities","Ocular effects (retinal thrombosis)","Depression"]

Clinical Tips & Counseling

Drug interactions

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FEMCON FE

Clinical safety rating: caution

Comprehensive clinical and safety monograph for FEMCON FE (FEMCON FE).

How it works

What the body does with it

Metabolism	Norethindrone is metabolized primarily via reduction and sulfate conjugation; ethinyl estradiol is metabolized via CYP3A4 and glucuronidation.
Excretion	Renal excretion accounts for approximately 40-60% of the dose as metabolites; fecal excretion is about 20-30% via bile. Unchanged drug excretion is minimal.
Half-life	The terminal elimination half-life of ethinyl estradiol is 13-18 hours; for norethindrone, it is 7-12 hours. Both allow once-daily dosing for contraceptive efficacy.
Protein binding	Ethinyl estradiol is approximately 98% bound to albumin and sex hormone-binding globulin (SHBG); norethindrone is about 80% bound to albumin and SHBG.
Volume of Distribution	Ethinyl estradiol: 2.3-4.1 L/kg; norethindrone: 3.6-4.5 L/kg. Indicates extensive tissue distribution, including reproductive tissues.
Bioavailability	Oral bioavailability: ethinyl estradiol ~40-45% (due to first-pass metabolism); norethindrone ~60-80%. Ferrous fumarate (iron supplement) has low bioavailability but is not relevant for contraception.
Onset of Action	Contraceptive effect begins after 7 consecutive days of active pills when taken correctly. Ovulation suppression may occur earlier.
Duration of Action	Duration of contraceptive effect lasts throughout the 21-day active pill cycle; after last active pill, effects wane over 5-7 days, leading to withdrawal bleed. Missed pills risk ovulation.

Classification & Brands

Dosing & administration

One tablet (norethindrone 0.5 mg + ethinyl estradiol 35 mcg) orally once daily for 28 days.

Dosage form	TABLET
Renal impairment	No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment due to potential estrogen accumulation.
Liver impairment	Contraindicated in severe hepatic disease (Child-Pugh class C). Use with caution in Child-Pugh class A or B; consider alternative contraception.
Pediatric use	Not indicated for use before menarche. Post-menarche: same as adult dosing (one tablet daily).
Geriatric use	Not indicated for use in postmenopausal women. No dose adjustment required for healthy elderly; consider risks of thromboembolism and metabolic effects.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for FEMCON FE (FEMCON FE).

Breastfeeding	Contraindicated in breastfeeding. Excreted in breast milk; may suppress milk production and cause adverse effects in nursing infants (e.g., jaundice, breast enlargement). M/P ratio not established; ethinyl estradiol and norethindrone acetate are present in low levels. Use alternative contraception.
Teratogenic Risk	FDA Pregnancy Category X. Contraindicated in pregnancy due to known teratogenicity. First trimester exposure is associated with cardiovascular defects, neural tube defects, and limb reduction defects. Second and third trimester exposure carries risks of fetal genital abnormalities (e.g., virilization of female fetuses from progestin component).