MODICON 21

Clinical safety rating: caution

Comprehensive clinical and safety monograph for MODICON 21 (MODICON 21).

How it works

Combination estrogen-progestin contraceptive; suppresses gonadotropins (FSH, LH) from pituitary via negative feedback, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; induces endometrial thinning.

What the body does with it

Metabolism	Ethinyl estradiol undergoes hepatic CYP3A4-mediated hydroxylation and conjugation; norethindrone is reduced and conjugated in liver.
Excretion	Renal (80% as metabolites, 20% unchanged); biliary/fecal (minor, <5% total)
Half-life	Terminal elimination half-life: 12–18 hours; clinical context: steady-state reached after 3–5 days of daily dosing
Protein binding	Ethinylestradiol: 97% bound to albumin; Norethindrone: 80% bound to albumin and SHBG
Volume of Distribution	Ethinylestradiol: 2–4 L/kg; Norethindrone: 3–5 L/kg; large Vd indicates extensive tissue distribution
Bioavailability	Oral: 40–60% (first-pass metabolism reduces systemic availability)
Onset of Action	Oral: 24–48 hours for contraceptive effect (ovulation inhibition); rapid onset if used for emergency contraception (within 72 hours of unprotected intercourse)
Duration of Action	Oral: 24 hours for contraceptive effect (requires daily dosing); duration of emergency contraceptive effect: single dose covers one menstrual cycle

Classification & Brands

Dosing & administration

One tablet (norethindrone 0.5 mg and ethinyl estradiol 0.035 mg) orally once daily for 21 consecutive days, followed by 7 drug-free days.

Dosage form	TABLET
Renal impairment	No dose adjustment required for chronic kidney disease. Contraindicated in acute renal failure or severe renal impairment (GFR <30 mL/min) due to potential fluid retention and electrolyte disturbances.
Liver impairment	Contraindicated in acute hepatic disease, hepatic adenomas, or impaired liver function (Child-Pugh class B or C). For mild hepatic impairment (Child-Pugh class A), use with caution; monitor liver function.
Pediatric use	Not indicated for use in pediatric patients before menarche. Safety and efficacy in postmenarchal minors established; dose same as adults (one tablet daily for 21 days, then 7 days off).
Geriatric use	Not indicated for use in postmenopausal women. No specific dose adjustments for elderly due to lack of indication; consider increased risk of cardiovascular and thrombotic events in women over 35 who smoke.

Use during pregnancy

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

Clinical note

Comprehensive clinical and safety monograph for MODICON 21 (MODICON 21).

Breastfeeding	Combination hormonal contraceptives reduce milk production and may pass into breast milk. M/P ratio not established. Use in breastfeeding is generally not recommended until breastfeeding is well-established (typically after 6 weeks postpartum).
Teratogenic Risk	Modicon 21 is a combination oral contraceptive. First trimester: Epidemiologic studies have not shown an increased risk of birth defects with inadvertent exposure. Second and third trimesters: Use is not indicated during pregnancy; fetal and neonatal risks include cardiovascular and genitourinary anomalies, though data are limited and confounded by maternal condition.

Warnings & precautions

■ FDA Black Box Warning

Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptives. Risk increases with age and heavy smoking (≥15 cigarettes/day); women >35 years who smoke should not use this product.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Thrombophlebitis or thromboembolic disorders (current or history)","Cerebrovascular or coronary artery disease","Known or suspected breast carcinoma","Endometrial or other estrogen-dependent neoplasia","Undiagnosed abnormal genital bleeding","Cholestatic jaundice of pregnancy or jaundice with prior pill use","Hepatic adenoma or carcinoma","Known or suspected pregnancy","Hypersensitivity to any component","Smoking and age >35 years"]

Clinical Precautions

Precautions

["Thrombotic disorders (thrombophlebitis, venous thromboembolism, arterial thromboembolism)","Cardiovascular disease (e.g., myocardial infarction, stroke) especially in smokers >35","Liver disease (e.g., hepatic adenoma, hepatocellular carcinoma)","Elevated blood pressure","Gallbladder disease","Carbohydrate/lipid metabolic effects","Ocular lesions (e.g., retinal thrombosis)","Headache/migraine","Bleeding irregularities","Depression"]

Clinical Tips & Counseling

Drug interactions

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MODICON 21

Clinical safety rating: caution

Comprehensive clinical and safety monograph for MODICON 21 (MODICON 21).

How it works

What the body does with it

Metabolism	Ethinyl estradiol undergoes hepatic CYP3A4-mediated hydroxylation and conjugation; norethindrone is reduced and conjugated in liver.
Excretion	Renal (80% as metabolites, 20% unchanged); biliary/fecal (minor, <5% total)
Half-life	Terminal elimination half-life: 12–18 hours; clinical context: steady-state reached after 3–5 days of daily dosing
Protein binding	Ethinylestradiol: 97% bound to albumin; Norethindrone: 80% bound to albumin and SHBG
Volume of Distribution	Ethinylestradiol: 2–4 L/kg; Norethindrone: 3–5 L/kg; large Vd indicates extensive tissue distribution
Bioavailability	Oral: 40–60% (first-pass metabolism reduces systemic availability)
Onset of Action	Oral: 24–48 hours for contraceptive effect (ovulation inhibition); rapid onset if used for emergency contraception (within 72 hours of unprotected intercourse)
Duration of Action	Oral: 24 hours for contraceptive effect (requires daily dosing); duration of emergency contraceptive effect: single dose covers one menstrual cycle

Classification & Brands

Dosing & administration

One tablet (norethindrone 0.5 mg and ethinyl estradiol 0.035 mg) orally once daily for 21 consecutive days, followed by 7 drug-free days.

Dosage form	TABLET
Renal impairment	No dose adjustment required for chronic kidney disease. Contraindicated in acute renal failure or severe renal impairment (GFR <30 mL/min) due to potential fluid retention and electrolyte disturbances.
Liver impairment	Contraindicated in acute hepatic disease, hepatic adenomas, or impaired liver function (Child-Pugh class B or C). For mild hepatic impairment (Child-Pugh class A), use with caution; monitor liver function.
Pediatric use	Not indicated for use in pediatric patients before menarche. Safety and efficacy in postmenarchal minors established; dose same as adults (one tablet daily for 21 days, then 7 days off).
Geriatric use	Not indicated for use in postmenopausal women. No specific dose adjustments for elderly due to lack of indication; consider increased risk of cardiovascular and thrombotic events in women over 35 who smoke.

Use during pregnancy

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

Clinical note

Comprehensive clinical and safety monograph for MODICON 21 (MODICON 21).

Breastfeeding	Combination hormonal contraceptives reduce milk production and may pass into breast milk. M/P ratio not established. Use in breastfeeding is generally not recommended until breastfeeding is well-established (typically after 6 weeks postpartum).
Teratogenic Risk	Modicon 21 is a combination oral contraceptive. First trimester: Epidemiologic studies have not shown an increased risk of birth defects with inadvertent exposure. Second and third trimesters: Use is not indicated during pregnancy; fetal and neonatal risks include cardiovascular and genitourinary anomalies, though data are limited and confounded by maternal condition.