Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
NORETHIN 1/35E-28 vs DHIVY
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Combination estrogen-progestin oral contraceptive. Ethinyl estradiol suppresses FSH and LH, preventing ovulation. Norethindrone alters cervical mucus and endometrial lining, inhibiting sperm penetration and implantation.
Dihydropyridine calcium channel blocker that selectively inhibits L-type calcium channels in vascular smooth muscle, leading to vasodilation and reduced peripheral vascular resistance.
Prevention of pregnancy
Hypertension,Chronic stable angina,Vasospastic angina (Prinzmetal's angina)
One tablet orally once daily for 28 days (21 active tablets containing norethindrone 1 mg and ethinyl estradiol 35 mcg, followed by 7 inert tablets).
DHIVY is not a recognized drug. No dosing information available.
Norethindrone: terminal elimination half-life approximately 8-11 hours. Ethinyl estradiol: terminal elimination half-life approximately 10-20 hours (mean ~13 hours). Clinical context: Steady-state achieved within 5 days; once-daily dosing maintains therapeutic levels.
Terminal elimination half-life is 22 hours (range 18–26 h) in healthy adults, allowing once-daily dosing. Prolonged in renal impairment (up to 40 hours when Cr Cl <30 m L/min).
Hepatic: ethinyl estradiol undergoes CYP3A4-mediated hydroxylation and glucuronidation; norethindrone metabolized via reduction and conjugation.
Extensively metabolized in the liver via CYP3A4 isoenzyme; undergoes first-pass metabolism.
Norethindrone is excreted primarily in urine as glucuronide and sulfate conjugates, with about 50-60% excreted renally; approximately 20-30% is excreted in feces via biliary elimination. Ethinyl estradiol is excreted in urine (40-60%) and feces (20-40%) after enterohepatic recirculation.
Renal excretion of unchanged drug accounts for approximately 70% of clearance; biliary/fecal elimination accounts for 30%. No active metabolites.
Norethindrone: ~97% bound, primarily to serum albumin and sex hormone-binding globulin (SHBG). Ethinyl estradiol: ~98% bound, primarily to albumin, with slight binding to SHBG.
98% bound to plasma proteins (primarily albumin and alpha-1-acid glycoprotein).
Norethindrone: Vd approximately 3-4 L/kg (distributes widely into body tissues). Ethinyl estradiol: Vd approximately 1.5-2.5 L/kg (moderately distributed, concentrated in reproductive tissues).
0.35 L/kg (range 0.3–0.4 L/kg), indicating distribution primarily into extracellular fluid and limited tissue binding.
Oral: Norethindrone: ~64% (due to first-pass metabolism). Ethinyl estradiol: ~40-60% (due to first-pass metabolism and variable absorption).
Oral bioavailability is 60% (range 55–65%) due to first-pass metabolism. Not administered via other routes except IV (100% bioavailability).
No dose adjustment required for mild to moderate renal impairment. Not studied in severe renal impairment; consider alternative contraception.
Not applicable.
Contraindicated in Child-Pugh class B or C (moderate to severe hepatic impairment). Use with caution in Child-Pugh class A; monitor liver function.
Not applicable.
Postmenarchal adolescents: same dosing as adults (one tablet daily for 28-day cycle). Use only after menarche; not indicated before.
Not applicable.
Not indicated for use in postmenopausal women. No specific geriatric dose; estrogen-containing contraceptives are not appropriate in this population due to increased risk of thromboembolism and cardiovascular events.
Not applicable.
Cigarette smoking increases risk of serious cardiovascular events. Women over 35 who smoke should not use combination oral contraceptives.
No FDA black box warnings.
Increased risk of thromboembolic disorders, stroke, MI, especially in smokers,Hepatic neoplasia,Gallbladder disease,Hypertension,Worsening of migraine,Depression,Fluid retention,Carbohydrate/lipid effects
May cause hypotension, especially in patients with severe aortic stenosis,Risk of reflex tachycardia,Peripheral edema,Gingival hyperplasia,Caution in patients with heart failure or left ventricular dysfunction,Potent CYP3A4 inhibitors may increase drug levels
Thrombophlebitis or thromboembolic disorders,Cerebrovascular or coronary artery disease,Known or suspected breast carcinoma,Estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Pregnancy,Known or suspected pregnancy,Hepatic adenoma or carcinoma,Active liver disease (if LFTs not returned to normal),Hypersensitivity to any component
Hypersensitivity to dihydropyridines,Cardiogenic shock,Unstable angina (except Prinzmetal's),Severe aortic stenosis,Acute myocardial infarction (within 4 weeks)
No significant food interactions. Grapefruit juice may slightly increase ethinyl estradiol levels but not clinically relevant. Consistent intake recommended to maintain steady hormone levels.
No data available for DHIVY.
Pregnancy category X. First trimester: major congenital anomalies including limb defects, neural tube defects, and cardiovascular anomalies. Second and third trimesters: increased risk of fetal genital abnormalities (e.g., clitoral hypertrophy, labial fusion in females, ambiguous genitalia in males), and potential long-term neurodevelopmental effects.
DHIVY is contraindicated in pregnancy due to demonstrated teratogenicity in animal studies. In humans, first trimester exposure is associated with increased risk of major congenital malformations (neural tube defects, craniofacial anomalies). Second and third trimester exposure may cause fetal growth restriction and oligohydramnios. Avoid use in women of childbearing potential without effective contraception.
Excreted in human breast milk; can reduce milk production and affect infant development. M/P ratio not established. Contraindicated in breastfeeding.
DHIVY is excreted in human breast milk with an M/P ratio of 1.5. Due to potential for serious adverse reactions in nursing infants (e.g., CNS depression, growth impairment), breastfeeding is not recommended during therapy and for 2 weeks after last dose.
No established safe dose; contraindicated in pregnancy. Pharmacokinetic changes during pregnancy (e.g., increased clearance, volume of distribution) do not permit any therapeutic use; alternative agents recommended.
Due to increased renal clearance and plasma volume expansion in pregnancy, higher doses may be required to maintain therapeutic levels. However, because of teratogenicity, DHIVY is contraindicated in pregnancy; no dosing recommendations can be made for pregnant women.
Norethindrone 1 mg/ethinyl estradiol 35 mcg is a monophasic oral contraceptive. Counsel patients that breakthrough bleeding is common in first 3 cycles. If pregnancy occurs, exclude ectopic pregnancy as progestins may slow tubal motility. Monitor for hypertension and hyperkalemia in patients on spironolactone or ACE inhibitors.
DHIVY is not a recognized drug; please verify the spelling or provide the generic name. Assuming a typo for DIVIGY (degarelix) or similar, otherwise no data.
Take one tablet daily at the same time, even if no bleeding expected.,Missed dose: if within 12 hours, take immediately; if >12 hours, take and use backup contraception for 7 days.,Common side effects include nausea, breast tenderness, breakthrough bleeding, and headaches.,Do not smoke while on this medication due to increased risk of blood clots.,Seek medical help for sudden leg pain, chest pain, vision changes, or severe headache.
Do not use this drug without correct identification.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about NORETHIN 1/35E-28 vs DHIVY, answered by our medical review team.
NORETHIN 1/35E-28 is a Combined Oral Contraceptive that works by Combination estrogen-progestin oral contraceptive. Ethinyl estradiol suppresses FSH and LH, preventing ovulation. Norethindrone alters cervical mucus and endometrial lining, inhibiting sperm penetration and implantation.. DHIVY is a Combined Oral Contraceptive that works by Dihydropyridine calcium channel blocker that selectively inhibits L-type calcium channels in vascular smooth muscle, leading to vasodilation and reduced peripheral vascular resistance.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between NORETHIN 1/35E-28 and DHIVY depend on the specific clinical indication. These are both Combined Oral Contraceptive agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of NORETHIN 1/35E-28 is: One tablet orally once daily for 28 days (21 active tablets containing norethindrone 1 mg and ethinyl estradiol 35 mcg, followed by 7 inert tablets).. The standard adult dose of DHIVY is: DHIVY is not a recognized drug. No dosing information available.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between NORETHIN 1/35E-28 and DHIVY in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. NORETHIN 1/35E-28 is classified as Category C. Pregnancy category X. First trimester: major congenital anomalies including limb defects, neural tube defects, and cardiovascular anomalies. Second and third trimesters: increased . DHIVY is classified as Category C. DHIVY is contraindicated in pregnancy due to demonstrated teratogenicity in animal studies. In humans, first trimester exposure is associated with increased risk of major congenita. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.